| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 405.1 | Electric powered gliders... | RGB::MINER | Dan Miner, DTN:225-4015, HLO2-1/J12 (@ H11) | Wed Apr 03 1991 15:17 | 21 |
| Since I've rambled on at length in note 387 (Beginner's Electrics),
I won't duplicate the effort here. Do:
Notes> dir/auth=miner 387.*
for a list of notes containing my experiences and opinions on
electrics.
I will say "BUY A COBALT MOTOR!"
(Sorry - I just had to sneak that in... :-)
_____
| \
| \ Silent POWER!
_ ___________ _________ | Happy Landings!
| \ | | | | |
|--------|- SANYO + ]-| ASTRO |--| - Dan Miner
|_/ |___________| |_________| |
| / | " The Earth needs more OZONE,
| / not Castor Oil!! "
|_____/
|
| 405.2 | Electro-Algebra...Hey, it can happen. | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Wed Apr 03 1991 15:55 | 43 |
| Jim, sorry to hear about the Algebra misfortune. What happened?
I assume you'll be using the outboard wing panels from the Algebra
wing as the basis for the quasi-F3E wing. I guess this would give
you 400-500 sq. in. of wing area.
You should shoot for a total flying weight of <= 40 oz. if using
a typical 120-130 watt 7 cell motor (Astro 05 cobalt, Graupner
Speed 500). This will give you poor man's F3E performance, but
how poor is poor, is a matter of personal preference.
Hobby Lobby sells that German motor (don't remember name or exact
price), >$100 but it has the same external dimensions as a typical
540 type "can" motor, and runs on 7 cells with a ~ 200 watt power
rating. That baby would really zing it up there, if price were no
object.
Your ideas on fuselage layout sound feasible. The fiberglass cloth
covering may be overkill, and extra weight for little return.
Layout your radio/motor/battery and see what minimum dimensions
you'll need to house everthing.
One of the fiberglass fuselages made by Jerry Slates may be a cost/time
effective alternative. His "Zen" fuselage appeals to me as the basis
for nice looking electric, it may be a little longer than necessary
for a ~ 70" span wing.
The group of guys in Calif. who are heavily into 7 cell F3E competition
all use fiberglass fuselages, and one of their group makes and sells
them. I don't recall any of their names. There was an article in
Model Builder about them within the past two years.
I've used speed controllers in all my electrics but find that I
fly in full throttle on or off mode 90% of the time. Speed controllers
are nice on landing approaches. F3E style flying doesn't really
warrent a controller, but all the serious competitors use them.
On\off switches are cheaper but you don't save much in bulk, weight,
or wiring.
Let me know how this project goes. Not having a flyable electric
for nearly a year, stirs feelings of electro-lust.
If my tax refund ever arrives, I might pick up a Robbe Arcus, NIB,
from a local guy. Always liked them but couldn't go the ~$200.
Terry
|
| 405.3 | Electric Thoughts | USRCV1::BLUMJ | | Wed Apr 03 1991 16:30 | 23 |
| The Algebra's wings were overstressed in flight during a pullout at
high altitude, so that's how I acquired the S3021 wings(tips off the
Algebra). Hobby Lobby sells a motor manufactured by Simprop the
2000-7 which they claim is 266 watts is $119. I inquired about this
motor in note 387.410 but this conference has been very inactive.
Are Astro-cobalt good high performance motors? I like Hobby Lobby
because they sell complete electric packages that eliminate the guess
work that a beginner might have. What kind of motor run can I expect
from a high performance 05 size electric on 7 900mah cells? My UHU
runs no more than 90 sec on 7 900mah scr cells. I would like to
improve the climb on the next elctric I build. Most of the magazine
columns tend to deal more with glow styled airplane conversions to
electric than high performance f3e type craft. My father is thinking
of building Larry Jolly's Electricus and is thinking of using a geared
Astro-cobalt 05. I have gotten interested in electrics after reading
about the F3E competitions. Hope to make the KRC fun fly being held
in Quakertown, Pa. this year. Gliders that fly power off over 100mph
and can stay up 5 minutes without power sound awfully exciting, albeit
expensive.
Regards,
Jim
|
| 405.4 | Do Androids dream of electric(R/C)sheep? | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Wed Apr 03 1991 17:43 | 23 |
| Length of motor run is dependent on too many things to predict without
specifying conditions. I could get three useful one minute motor
runs on 7, 900mah cells with a direct drive. Useful meaning able
to climb back to winch launch altitude. Using the same motor/battery
with 3:1 gearing would extend useful run time to 4-5 min. but climb
rate was lower, so it's a tradeoff.
F3E rules specify 20 sec. max motor run and this is done twice during
a typical duration round, so if you can't dump all of your available
power in less than a minute, you have wasted potential. Most serious
F3E motors are designed with this in mind.
The Simprop is the motor I was thinking of. What's the cheapest
an Astro 05 cobalt goes for now? At least $70, so the Simprop at
twice the power may be worth the extra $, if its quality matches
the Astro.
Jeez, the more I think about this the more I am seized with the
desire to rush off and SPEND,SPENd,SPEnd,SPend,Spend,spend, whew...
in less than a minute you've got wasted potential. Most serious
F3E motors are designed to take advantage of these conditions
|
| 405.5 | Astro Cobalt 05 is a great choice! | HPSPWR::WALTER | | Wed Apr 03 1991 17:53 | 14 |
| >>> What kind of motor run can I expect
>>> from a high performance 05 size electric on 7 900mah cells? My UHU
>>> runs no more than 90 sec on 7 900mah scr cells.
That's about what my Challenger gets from 7 900mah cells powering a geared Astro
Cobalt 05 turning a 12 x 8 prop. I think it's overprop'd, but it leads to
spectacular climb rate. I'd guess 1000 feet per minute. I typically get two
good climbs to thermalling altitude per charge.
I've always wanted to experiment with a smaller prop, but finding a selection
of folding props is not easy. I suppose I could try a non folding prop, but it's
pretty likely to break on landing.
Dave
|
| 405.6 | Astro Cobalt 05-FAI = 200 watts | RGB::MINER | Dan Miner, DTN:225-4015, HLO2-1/J12 (@ H11) | Wed Apr 03 1991 19:36 | 20 |
| The Astro cobalt "05-FAI" delivers 200 watts also. This is a
special wind of the standard 05 (only 125 watts) and since it's
putting out more power, it pulls more current and runs down the
batteries quicker.
I have both a standard cobalt 05 a cobalt 05-FAI. There is a
noticeable difference between the two.
See note 387.213 for specs, etc...
_____
| \
| \ Silent POWER!
_ ___________ _________ | Happy Landings!
| \ | | | | |
|--------|- SANYO + ]-| ASTRO |--| - Dan Miner
|_/ |___________| |_________| |
| / | " The Earth needs more OZONE,
| / not Castor Oil!! "
|_____/
|
| 405.7 | Astro Flite cobalt 05-FAI data | RGB::MINER | Dan Miner, DTN:225-4015, HLO2-1/J12 (@ H11) | Wed Apr 03 1991 19:44 | 21 |
| Oops. I just went and re-read 387.213 and found out that the 05-FAI
is not listed in that note... Data is:
Astro Flite Cobalt 05-FAI
Power output 200 watts
Direct drive 7x6 prop @ 14,000 RPM
Geared drive 12x6 prop @ 6,000 RPM
All other data (dimensions, weight, etc.) are the same as the
standard Astro Cobalt 05.
_____
| \
| \ Silent POWER!
_ ___________ _________ | Happy Landings!
| \ | | | | |
|--------|- SANYO + ]-| ASTRO |--| - Dan Miner
|_/ |___________| |_________| |
| / | " The Earth needs more OZONE,
| / not Castor Oil!! "
|_____/
|
| 405.8 | Well, maybe it's not so difficult to get *close* | LEDS::COHEN | So much for Armageddon! | Thu Apr 04 1991 12:33 | 26 |
| > Length of motor run is dependent on too many things to predict without
> specifying conditions. I could get three useful one minute motor
> runs on 7, 900mah cells with a direct drive. Useful meaning able
> to climb back to winch launch altitude. Using the same motor/battery
> with 3:1 gearing would extend useful run time to 4-5 min. but climb
> rate was lower, so it's a tradeoff.
Gotta disagree a bit. Motor power ratings are specified with a specific
manufacturers recommended prop. If you fly this prop, the math works
quite well.
Power = Volts * Current. A Motor that's delivering 200 Watts from a 8.4
Volt source pulls 23 Amps from the battery pack. If you had a 23
Amp/Hour pack, the motor would run for one hour. A 900 Ma/Hour Pack is
approximately 1/25 the capacity of a 23 Amp/Hour pack. It will
therefore run the motor for 1/25 of an hour or 2.4 minutes. Since
nothing in life is perfect, this type of calculation should be derated a
bit, say 5%. Additionally, since the motor unloads once the plane is
flying, the draw does actually go down some, so the figure should be
uprated a bit, say 15%. But really, in practice, just the plain, simple
math will get you in the right ball park.
For reference, typical full power flights on my direct drive Astro
Cobalt 05 turning a 7-6 (I think the Astro recommended prop is an 8-4,
so I'm close) in an ElectriCub last in the 4.5 to 5 minute range, which
is right in line with the math, above.
|
| 405.9 | | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Thu Apr 04 1991 13:02 | 16 |
| I'll agree with your math, and if the motor maker specifies a prop.
The German motors don't specify props, however there are charts
floating around that give current draw using a range of props on
certain motors.
On Graupner motors, with Graupner props, I've had good results by
going up 1" in diameter and one step in pitch over what is specified.
Ie, from 7X3 to 8X4.5.
The same motor with a Freudanthaler prop is happy with a 9X5 and
I have gone as high as 12X6.5 without affecting duration too much,
although blade length interfered with the wing l.e. when folding,
in that particular experiment.
Ya' know the old saying: "Torque 'er till she smokes, then three
more turns".
Terry
|
| 405.10 | Electric power is confusing | USRCV1::BLUMJ | | Fri Apr 05 1991 10:37 | 38 |
| Well it looks like I'm going to be forced into making a choice for a
new motor. Yesterday I went out fly my Uhu, I threw the ship it climbed
for about 2 seconds then the motor quit. I took it home put it on my
bench directly connected to DC power supply. It would only start
running if you manually twisted the shaft, and would only achieve maybe
500 RPM. Obviously the motor is shot. I am not pleased about this
as the motor has only been run about 10 times. Hopefully my next motor
will have a longer life! Well I called Hobby Lobby and talked with a
fellow(Randy) about a suitable replacement(other than stock). I am
more confused than when I started. He felt the Simprop 2000-7 would
be a good choice. I told him that I had the Power Switch 20 BEC/On-off
switch(standard Uhu config) which is rated in their catalog at 150
watts max and 20 amps. He said he was running this motor in his Uhu
and had not experienced problems. Hmm, their catalog rates the 2000-7
at 266 watts, the manufacturer's chart says this motor will draw 23
amps with 8-4.5 prop driven with 7 cells. With the power switch 20
rated as stated above this seems to be asking for trouble. Randy
claims that this motor only draws about 14 amps during their empirical
bench tests. I can buy 9 stock Uhu motors for the price of 1 Simprop
2000-7, so I am thinking cautiously before buying. In fact if I buy
the Simprop 2000-7($119) with the recommended speed controller($138)
and an 8-4 prop($20), I just spent $277 to power my simple, entry level
Uhu! I then asked Randy about the Mabuchi RX540VZ which their catalog
rates at 144 watts. He said this motor is much to hot for use with
folding props, indeed he claims that using this motor in The GRaupner
Race rats has caused numerous broken folding props. He says that this
motor is wound for speed and is to be used with regular glo engine
props. I asked about Astro Cobalt motors, and he said that they
heartily recommend the 25 size and up, but feels that the smaller
motors are inefficient, drawing too much current. I need some
honest answers and a good recommendation. I will power whatever
motor I get with a 7-cell 900mah pack, and it must be direct drive.
Any help is appreciated.
Thanks,
Jim
|
| 405.11 | Check your brushes/springs | ZENDIA::REITH | Jim Reith DTN 226-6102 - LTN2-1/F02 | Fri Apr 05 1991 11:04 | 14 |
| Jim,
My son had a similar problem with his RC car (after a few more runs
than you've had though) It turned out his brushes were worn to the
point where the brush springs wouldn't hold them firmly against the
commutator. New brushes were about $4 and he was back in business. I
don't know how servicable the Uhu engine is but it sounds like you've
got nothing to lose at this point and it might give you a little more
service from it while deciding on the next engine.
Jim
P.S. The springs go in a slot in the brush carrier on his motor. The
brushes had worn to where the spring bottomed out in the slot.
|
| 405.12 | Speed 500 | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Fri Apr 05 1991 11:15 | 20 |
| If I remember correctly, the stock Uhu motor is a Speed 600, rated
at ~104 watts. A good substitute is the Speed 500 rated at 125 watts.
They are both in the $15-$20 dollar range for the bare motor. The
Speed 500 is slightly shorter and lighter than the 600.
Hobby Lobby sells two types of Speed 500s. One is $50+ and has ball
bearings etc. I don't recall the part# for the cheaper one. Look
in the H.L. catalog chart.
The Speed 500 takes my 41 oz.,76" Thermal Traveler up quite briskly.
It should work fine on an Uhu.
I think it states in the catalog that it is a good choice as an
Uhu hop-up. It spins an 8 X 4.5 Scimitar real well.
It's interesting about the 14 amp current draw. My 600s and 500
will blow a 20 amp fuse everytime when run in static conditions.
What would happen in the air, unloaded, I've never tried. I run
them with a 30 amp fuse, and never have problems.
The Graupner power switch would probably work ok with the 500.
Terry
|
| 405.13 | Hobby Lobby Motor Specs | USRCV1::BLUMJ | | Fri Apr 05 1991 15:15 | 13 |
| Terry,
Its interesting that Hobby Lobby's Speed 500 Race which they call a
hop up over the standard Uhu motor actually sells for less 40 cents
less than the standard Uhu motor, and the 8.4 Volt speed 600 which
they advertise also as a hop up(when used with 8-4 prop) sells for
80 cents less than the standard uhu motor. It is hard to figure out
which motor really would give better performance, I wonder if there
really is that big a difference.
Regards,
Jim
|
| 405.14 | | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Fri Apr 05 1991 15:36 | 17 |
| I can tell you from personal experience that the Speed 500 does
give a noticeable increase in climb rate over the Speed 600, both
used in the same airplane, and with three different props. 7X3,
8X4.5, and the older non-Scimitar Graupner prop which was about
a 12 X 5, but the blades were so flexible that it was more like
a 3 or 4 pitch under load.
The pricing of all those Graupner motors is rather odd. What's
the point of having <$1.00 difference over a range of 5 or 6 models?
Any of the 500 or 600 series can be run on 6, 7 , or 8 cells, so
some of the hop-up results can be had by simply increasing the
cell count, which is usually more expensive than buying a new motor.
BTW you do break in your motors before flying don't you ?
The two flashlight cell technique works as well as any.
Terry
|
| 405.15 | Electric Power | USRCV1::BLUMJ | | Mon Apr 08 1991 09:47 | 7 |
| I have ordered the Speed 500 with an 8-4.5 Graupner folding prop
from Hobby Lobby. I will report how this combination works
in comparison with the standard speed 600 with 7-3 prop.
Regards,
Jim
|
| 405.16 | Another grounded UHU for motor failure | KBOMFG::KLINGENBERG | | Mon Apr 15 1991 10:39 | 53 |
| Jim,
sorry for answering so late! I was off some time due to the flu and a
move of our home and then had to catch up on work before catching up on
Notes. Although I hesitate a bit to discuss Elektro-UHU problems in a
F3E topic, I am in a similar boat as you are. Have you already tried
your SPEED 500? Please keep us (me) posted on the results!
I went out flying my UHU last Saturday for the first time after the
move. First flight was fine, second (different battery, both 6-cell
1200 SCR) seemed to be with very low power. I suspected the battery
because of the layoff of a few weeks. Then, for the third time, the
motor didn't even start. I measured the resistance, and found
unlimited... I obviously shot the (stock) motor. I don't know what
ruined it - was it the bigger prop I used (8.5 x 4), was it the long
time I flew it with a switch and not with a controller (higher wear of
collector due to the high start/stop currents) or had it just reached
the expected lifetime? It had served me for many many flights, and I
don't complain.
I used to have the SPEED 600 BB in the UHU, too, but ruined that with
flying in the snow (got the fuse full with every landing, the motor
rusted and finally got rust or ice into the collector. Had an idle (!)
current of 60 A without a prop at all then...). Since I like my UHU a
lot, I want to replace the motor once more, but would like to
experiment a bit. And to upgrade, of course...
The question is: Upgrade - in what direction? Flight time? Speed? Climb
rate? The solution would probably be different for either way. I once
tested the (50+$) SPEED 500 BB RACE that I have for my RACE CAT in the
UHU. It worked nice, but the mismatch was even worse than with the
original motor. So, the performance wasn't as good as expected and the
upgrade wouldn't be worth the money - except your preferred flying
style was hot dogging. I expect similar results with any motor that was
designed with pylon racing in mind. The ASTRO Cobalt 05 FAI as well and
maybe even the Simprop - Although I have no data of this one.
I would like to try to improve flighttime (runtime as well as gliding
time). With this in mind, I probably have to go geared. Maybe I'll even
use a smaller motor (SPEED 400) with the GRAUPNER belt drive. I'll need
to dig up old mags, calculate a bit and shop around. But I seem to
recall that I once read about an UHU with this combination that usually
flew 30 minutes without thermals. And I still remember my first
electric 10 years ago, GRAUPNER Mosquito scratch built fuse with 2.80 m
wing (110"). It had a lot less input power than the UHU has now
(although it was bigger/heavier) and it always flew 20 to 30 minutes.
But the climb rate will suffer. It depends what you want.
I hope to go shopping tomorrow and will keep you posted what I end up
with.
Best regards,
Hartmut
|
| 405.17 | | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Mon Apr 15 1991 12:28 | 20 |
| Hartmut,
I've used the Graupner belt drive system with a Speed 600 and 11X6
prop on a 112", 64 oz. glider and it took it up adequately but not
spectacularly of course.
I'd be surprised if there is sufficient vertical space in a UHU
fuselage to house the belt drive. It may be possible to use the
3:1 gearbox drive that screws on to the front of the motor. It has
much less offset than the belt drive, but the motor would probably
have to be repositiioned higher in the fuselage to get a straight
shot out the centerline of the fuselage.
Last weekend our local Robbe Kormorande owner got it flying pretty
well. He installed an AStro 05 cobalt on 6 cells, 8X4.5 prop.
He has a helper launch it, then switches on when the prop is clear
of his arm. Climb is surprising for 6 cells and duration is better
than 7 cells. The glide isn't much by conventional sailplane standards
but he had an external antenna, so improvement is possible.
Terry
|
| 405.18 | Thanks, I'll take calculator AND plan with me | KBOMFG::KLINGENBERG | | Mon Apr 15 1991 13:47 | 25 |
| Terry,
I plan to have the UHU plan and a calculator with me when I go
shopping. Thanks for the hint. I have all the room under the canopy
free, so using an extended shaft might be a solution to get the belt
drive in. I certainly don't want to destroy the nice pilot my wife
painted. BTW, I was always interested in the GRAUPNER belt drive system
for maybe a bigger thermal electric glider (still have those 2.80 wings
at my parents'). How many cells did you use it with? I understand you
can increase the number of cells even on a 7.2 V motor as long as the
current stays within it's limit.
Thanks for the encouraging words on the Kormoran! That is exactly the
setup I have! I put the ASTRO cobalt 05 in (souvenir from last years
business trip to the USA, they are over $ 150.- here!). This is one of
the few rare-earth magnet motors where you can adjust the timing (for
reverse running), and I've got the aeronaut 8 x 4.5 prop, too. And I
hid the antenna in the wing, as the instructions suggest. I just didn't
find the time to test fly it due to the move. And I have to straighten
one aileron (maybe build a new one). It's not straight, and I don't
want to take risks like that with a plane with a new concept (to me at
least).
Best regards,
Hartmut
|
| 405.19 | 7 | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Mon Apr 15 1991 13:58 | 13 |
| I used 7 cells with the belt drive. The Speed 500/600 is supposed
to be able to handle 8 cells with no problem.
The belt drive system comes with a fairly long shaft, which you
cut to suit your individual installation. It may be long enough
to reach the nose from the canopy in the Uhu.
I also have a Speed 700 motor for 10-12 cells. I haven't found a
suitable application for it yet, but would like to try it in the
112", after I make new wings. The 700 motor diameter is too large
for the belt drive system to fit. The belt support housing is designed
to fit around the case of the 500/600 series.
Terry
|
| 405.20 | More UHU observations | USRCV1::BLUMJ | | Thu Jun 06 1991 10:25 | 25 |
| After flying my UHU more this year(with speed 500 and 8x4.5 prop) and
7-cell 900mah, I think that it is underpowered. To climb it is
necessary to achieve speed at level flight and then use the speed to
attain altitude, repeating this until sufficient thermal altitude
is achieved(at great expense to the battery). I have enjoyed flying it
on slopes where the lift helps keep it up. To keep it up in thermals
seems to require that you get up high where thermals are better
developed, but then with its 66" wing it is hard to see. It is a fun
ship to fly, but with anemic climb and high wing loading it has its
drawbacks. I would like to put a more powerful motor in it, but this
will require a different battery eliminator/on-off switch (the power
switch 20 is only rated at 20 amps). Also the cheap charger I bought
is just about worthless. Making mistakes in electric flight is very
expensive. My father has decided to electrify his MIRAGE sailplane and
the price tag with 05 GEARED ASTRO is $348. IF I had to purchase the
UHU again I would buy the POWER SWITCH 25 which only costs $7 more than
the power switch 20, I would get a quality charger, and probably the
Simprop 2000-7 or other 200 watt+ direct drive motor. This would raise
the price tag of the Uhu - $UHU kit = $90 Astroflight charger = $82
Battery = $42 POWER switch 25 = $63 Simprop 2000-7 motor = $119 prop =
$25 total cost = $421(wow).
Regards,
Jim
|
| 405.21 | | CSOVAX::MILLS | | Thu Jun 06 1991 12:33 | 13 |
| I'm running the power switch 20 with a Astro Cobalt 05 and it runs
great. Astro weighs less and is more powerfull (sucks battery down
too). With the 7 x 3 graupner prop I can use a 20 amp fuse. With the 8
x 4.5 prop it requires 25 amp. BUT !!! if I run the 20 amp fuse on the
"Bench" it runs about 15 seconds before it blows. Meaning when Flying
I'm confident the astro with the 8 x 4.5 is pulling less than 20 amps.
But 8 x 4.5 on astro 05 is way to powerfull for me and I run the 7 x 3
regulary on UHU. But I have s133 servos and 700mah pack which may be
lighter than yours. I regularly run an 8 x 5 (wood prop) on the astro
05, power switch 20 and 25 amp fuse on another ship and runs great.
I agree, it thermals great way up there when it's impossible to see :-)
|
| 405.22 | More UHU Questions | USRCV1::BLUMJ | | Thu Jun 06 1991 16:10 | 14 |
| re: -1
Is your ASTRO 05 the geared version, is it the 125 watt or 200watt
version. How do you have it mounted? How long does it run on a charge?
My Uhu with standard servos and 7-cell 900mah pack weighs 46 oz. What
type of charger are you using. Thanks for any information.
Regards,
Jim
|
| 405.23 | Astro 05 fits right in UHU | CSOVAX::MILLS | | Fri Jun 07 1991 11:52 | 11 |
| I made a mistake in .-2 I do have 900mah packs also not 700mah. It's
not geared and not the FAI (hotter) motor. It mounts just like the
speed 600/500 no mods. I did make an aluminum plate for the nose that I
silconed glued to the front for when I was using the SPEED 600. This
really strengthens the nose up. Using micro servos in an electric saves
an ounce that really counts :-).
I have the ASTRO flight model 112 (I think) (not constant current and
not auto peack). But does have variable current, ammeter and discharge
circuit. I wish I got the auto peak (model 115 I think) sometimes.
|
| 405.24 | More poer questions | USRCV1::BLUMJ | | Fri Jun 07 1991 12:05 | 15 |
| I am somewhat confused about powering gliders with electric motors.
I am currently using a Graupner Speed 500(rated at 120 watts) with
8x4.5 Graupner prop. The Uhu is definitely not "overpowered", in fact
under power it is very hard to keep it from stalling. Why would an
ASTRO non-geared 05(rated at 125 watts) with 7x3 prop provide such a
difference in climb performance? Maybe the Graupner motor is not
really 125 watts? It is my feeling to increase the climb of the Uhu
I need to spin a bigger prop, which requirea a motor and speed
controller that can handle the additional current. Is it possible the
ASTRO gives better performance because it is spinning its comparably
sized prop faster than the Speed 500? Any help is appreciated.
Thanks,
Jim
|
| 405.25 | | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Fri Jun 07 1991 14:32 | 25 |
| Jim,
I notice that your Uhu weighs 46 oz. This goes a long way toward
explaning its climb performance.
My Thermal Traveler at 41 oz., and same motor/prop combo, could
hold a steady 10-15 degree climb angle for the first 1-2 minutes
of the flight, which meant out-of-sight, but I never let it get
that far.
I was using micro servos, S-33, and SR SCE 1200 battery which is
~ 30 grams lighter than the usual Sanyo SCR 900 packs. However,
climb performance didn't suffer when I used SCRs because the greater
power more than made up for the greater weight.
Frankly, I've never noticed any worthwhile performance increase
between a Speed 500 and an Astro 05, using comparable props/batteries.
Going to a geared motor/larger prop on the Uhu would give you a
steeper climb angle. Level flight would be the same or slightly
slower than direct drive, depending on prop size.
If you could reduce the Uhu's weight a little (probably not too
easy at this point), some of your problems would be solved.
Terry
|
| 405.26 | A couple cents more worth | CSOVAX::MILLS | | Sun Jun 09 1991 09:18 | 22 |
| I agree with .-1 partially. But 125 watts does NOT equal 125 watts. I'm
not familiar with SPEED 500, but I believe it's a cheap motor (just a
different winding of the 600). Even if it does put out what the astro
05 does (which I doubt) it weighs less I'm sure. Switching to micros's
and an astro 05 will save some critical weight. The motor is such high
quality it is worth the investment.
I think you will loose using a speed control. Because the speed control
has loss and you will have to add weight for the rx pack. Unless you
want to fly with motor constant on (which is where you want a speed
control) like for an electro-streak.
Using geared is confusing and I have not yet. But I think it works this
way. For a slow flying plane you want geared. You can also pull as much
current by turning a bigger prop at slower RPM. This allows the plane
to fly closer to the speed that the prop is trying to push it (and maxs
the efficientcy due to less slippage). Running a large prop (direct
drive) at half throttle on a speed control will strain the motor and
runs less efficient because the speed control is even less efficient at
partial throttle (I believe). The UHU is more a fast flyer than a slow
and it seems to fly well with direct.
|
| 405.27 | Electric Questions | USRCV1::BLUMJ | | Mon Jun 10 1991 11:31 | 56 |
| This weekend I researched 7-cell motors, because I am not satisfied
with my UHU's rate of climb. The only way I can reduce the weight is
by going from standard to micro servos. The plane weighs what it was
advertised, so I don't think it's worth the trouble.
Manufacturer Watts Price Weight Diameter Magnet Type
************ ***** ***** ****** ******** ***********
Astro 05 125 $83 6 1/2 oz. 1 1/4" sam. cobalt
Astro 05 FAI 200 $100 " " "
Simprop 266 $119 7 3/4 oz 1 3/8" ferrite
Graupner-3303 201 $229 9.0 oz 1 7/16" sam cobalt
Graupner-3303S 272 $259 " " "
Graupner-ULTRA 384 $256 13.0 oz. 1 3/4" "
Keller 22/9,12 160 $140 8.8 0z. 1 3/8" neodym
Keller 25/8,10 190 $170 10.8 oz. " "
Keller 35/5,6,8 260 $189 11.8 oz. " "
Keller 40/8,10 300 $200 12.7 oz. " "
Keller 50/5,6,7 360 $219 14.0 oz. 1 9/16" sam cobalt
Asto prices - Hobby Lobby
Graupner prices - Hobby Lobby
Keller prices- Robbe
Simprop prices - Hobby Lobby
All the above motors are direct drive, however Astro offers the 05 FAI
(200 watts) in a geated version for $125. All the manufacturers claim
these motors will run on 7-cells.
Can someone explain the relationship between watts and the ability of
the motor to lift a sailplane. My interest is to get a glider up
quickly, I do not care about run time, speed at level flight, only
rapid climb. Hence if a motor only runs 1 1/2 minutes, but allows 3
climbs to 500 ft., that would be great. The more research I have done
on electric motors the more confused I've gotten. There does not seem
to be any rating standards. Hobby Lobby lists the Keller 80/8 motor
at 1740 watts, while Robbe rates the same motor at 600 watts. DO WATTS
MEAN ANYTHING!!! I really need this question answered. From the above
chart it seems that the Astro 05 offers the most for the money(light
weight, Samarium Cobalt magnets, decently watts for the $). My father
will be gettin an 05 Astro(geared) this week. I am going to set up a
test jig and will report on some of the motors I end up with(ie how
much current is drawn spinning different sized folding props. If seems
that the only way to find out about these motors is empirically. Most
of the articles and testing seem to have been done with glow engine
props. Very little has been written about powering gliders. I'd like
to hear from anyone with knowledge/experience.
Thanks,
Jim
|
| 405.28 | Still trying to convince you | CSOVAX::MILLS | | Mon Jun 10 1991 11:57 | 15 |
| I guess that I have not convinced you that my UHU runs Great with just
the ASTRO 05 and micros. Just because you meet the weight spec doesn't
mean anything. If all your interested in is getting up there for the
glide then go with the lightest motor that will do the job. In fact
ASTRO flight recommends an 035 for UHU. With the 8x4.5 I can climb at
about ~35 degrees for two climbs. With the 7x3 I get 3 climbs at ~15
degrees. Watts is how much it draws not what it puts out. It depends on
how efficient the motor is. Cobalt magnets are more efficient. Bearings
have less friction etc. Get the micro servos first and you'll see what
a difference an ounce will make.
I use this same drive setup in my Mirrage 550 and I can fly off the
water!!! in 30 ft. I know of people in this notes file that couldn't
get thier gas powered plane off the water !!!
|
| 405.29 | DC motors 101 | USRCV1::BLUMJ | | Mon Jun 10 1991 12:37 | 15 |
| RE: -1
I do believe your UHU climbs well with an Astro 05, in fact this is
most likely the motor I will be getting. What I don't understand
is why it doesn't climb that well with a speed 500 rated at 120 watts
(the Astro is rated at 125 watts). How does torque figure in the
equation? In other words maybe the Astro can turn the prop faster than
the speed 500? If Power = volts x current and I = volts/resistance,
I would assume that the better quality motors have lower resistance,
and since voltage is constant, the current it will draw is higher.
So is this why the power draw is higher on better motors?
Thanks,
Jim
|
| 405.30 | Internal bushing/bearing drag will make a difference | ZENDIA::REITH | Jim Reith DTN 226-6102 - LTN2-1/F02 | Mon Jun 10 1991 13:19 | 4 |
| Power to watts is a fair measurement only if the friction is the same.
More friction will help stall the motor some and cause a higher draw
and less RPMs. Chances are that Astro has worked that side of the
equation out over the last 20 years of making motors.
|
| 405.31 | Motor wire | USRCV1::BLUMJ | | Mon Jun 10 1991 14:17 | 6 |
| Is 12 gauge stereo speaker wire ok to use for electric motor
installation? It is supposed to be fairly low resistance.
Priced right to!
Thanks,
Jim
|
| 405.32 | ROBBE ARCUS | USRCV1::BLUMJ | | Mon Jun 10 1991 15:26 | 16 |
| Earlier in this note I was trying to find sources for fiberglass
fuselages. I have received the Robbe catalog, and they sell the
ARCUS fuselage separately for $59.95, the canopy for $6.95, and
the tailfeathers for $7.95. The entire kit is $149, so if you
are willing to build you own wing, you can save over $70. The
ARCUS is a 2-meter design using the EPPLER 176-180 airfoil, it
has 511 sq. in. wing. Wing loading is 15-18 oz./sq. ft. depending
if 7 or 10 cell operation is chosen. Separate servos are wing
mounted in the aileron version using computer control for differential,
a poly version is also shown. The wing is mounted with nylon bolts.
overall it looks like a nice design, which can accomodate direct or
geared motors.
Regards,
Jim
|
| 405.33 | One more opinion on the Astro 05 | HPSPWR::WALTER | | Mon Jun 10 1991 18:17 | 4 |
| The Astro 05 should pull the UHU with authority. I have one in my
Challenger, geared, 12-8 folding prop, and 7 - 900 mAHr cells. This
setup climbs with urgency, will get 2 or 3 pulls to 500 feet or so.
My plane weighs about 43 oz.
|
| 405.34 | re: -1 | USRCV1::BLUMJ | | Tue Jun 11 1991 09:38 | 9 |
| re: -1
Is the Astro 05 in your Challenger the 125 or 200 watt version?
I would think that a geared 05 spinning a 12-8 prop on a 43 oz.
ship should give awesome climb.
Thanks,
Jim
|
| 405.35 | Challenger w/ cobalt 15 geared | RGB::MINER | Dan Miner, DTN:225-4015, HLO2-1/J12 (@ H11) | Tue Jun 11 1991 11:43 | 18 |
| If you want *REALLY* spectacular climb (approx 75 degrees), try an
Astro Challenger on an Astro Cobalt 15 geared w/ 12 cells @ 900mAh
(the standard "cobalt 15 geared SYSTEM") using a 12x8 prop.
You can easily get 5-8 climbs to winch launch height (only takes
about 20 seconds or less) and 15 to 20 minute flights in dead air.
It's a winning combination.
_____
| \
| \ Silent POWER!
_ ___________ _________ | Happy Landings!
| \ | | | | |
|--------|- SANYO + ]-| ASTRO |--| - Dan Miner
|_/ |___________| |_________| |
| / | " The Earth needs more OZONE,
| / not Castor Oil!! "
|_____/
|
| 405.36 | UHU UPGRADE ordered | USRCV1::BLUMJ | | Tue Jun 11 1991 12:37 | 21 |
| After talking with Larry Sribnick at SR Batteries (he sells electric
motors, batteries, chargers, etc.), I have ordered the following:
Astro 05 FAI direct drive motor- $97.95
Astro 110A peak detecting charger - $82.95
He also offers an 1100mah 7 cell battery that weighs 9.45 oz for $45.50
I probably will have to junk the Graupner power switch 20, I will bench
test the motor to see how much current it draws. I will probably buy
the Graupner mini-switch 40(handles 300watts, 40amps) and use a 250mah
battery for the receiver. I am buiding an 83" wing for the UHU using
the Selig 3021 airfoil. This is why I went with the FAI motor. I will
start with a Graupner 7-3 prop and see how it climbs. I will report
the results.
Regards,
Jim
|
| 405.37 | Good choice | CSOVAX::MILLS | | Tue Jun 11 1991 14:52 | 5 |
|
Just sit the plane vertically on the ground, stand back and turn it
on :-). Good choice...and good luck. I just bought an astro 05 geared
and 11-6 prop myself today for my spectra :-).
|
| 405.38 | 125W cobalt | HPSPWR::WALTER | | Tue Jun 11 1991 17:34 | 5 |
| Re: .34
Nope, mine is the standard 125W motor. I wouldn't call the climb
"awesome", but it is impressive when compared to say the Eclipse
or Electra running a stock can motor. When I hand launch it, there's
no need to fly level to establish speed. It climbs out immediately.
|
| 405.39 | Astro 05 Shaft Question | USRCV1::BLUMJ | | Tue Jun 11 1991 17:44 | 13 |
| I am confused about the shaft of the Astro 05. Is it a 4mm shaft
with a flattened area ? The Hobby Lobby catalog is kind of con-
fusing it states as follows - 4.0 + 3/16(shaft diameter specs mm from
specifications chart, pg. 43 of recent catalog) "This is the diameter
of the bare shaft without the included prop hub. The bare shafts have
flattened portion for set screw." I don't know what the "+3/16" means.
Can anyone help? Hobby Lobby sells Freudenthaler props with 4mm prop
shaft adapters, does anyone know if these props slip right on the Astro
4mm+3/16 shafts? Thanks again for any help.
Regards,
Jim
|
| 405.40 | Indirect answer | CSOVAX::MILLS | | Wed Jun 12 1991 00:32 | 24 |
| I don't know the sizes but I know this much. I called Hobby lobby with
the same problem and they told me they didn't have a folding props that
would mount without mods (at least graupner ones). They said some
people drill out the smaller one. I missed :-( on my first drilling.
But the second time I got it perfectly square. It's impossible with out
a drill press (which I had on both trys). An alternative which I also
used and worked fine (but does not look as nice) was to leave out the
compressing pin and drilled a plastic bushing to keep the compression
nut centered on the stock astro adapter (not nearly as hard to drill).
But you can't mount the spinner cap and the cap does not fix the blade
blade position when running. If you do plan to drill a graupner one
I'll let you know the trick I used to not "miss".
I know Kay Fisher runs a sonotronics folding prop on his astro 05. I
personally don't like the floppy blades (although they could save you a
finger some day) and he seems to run fine with it. I think master screw
also makes one a lot like sonotronics but has blades similar to the
graupner. Tom's has all of these including graupner ones. I saw them
today when I bought my 11-7 graupner one for a new geared cobalt (which
is yet another size).
I don't know about the Freudenthaler props. But I've seen the table
your refering to and I think they offer they same sizes as graupner
(metric sizes).
|
| 405.41 | Astro 05 Prop Choices | USRCV1::BLUMJ | | Thu Jun 13 1991 09:47 | 13 |
| RE: -1
Are replacement 3.2mm collets available from Graupner/Hobby Lobby?
By the way am I correct in assuming that thge Astro 05 shaft is indeed
4mm? Hobby Lobby sells a 4mm prop adapter for Graupner props, however
the smallest prop that you can use with this setup is 9-5 which may be
to big. What do you think? Experimenting with props is an expensive
proposition, but then again everything about electric flight is pretty
expensive. Thanks for any help.
Regards,
Jim
|
| 405.42 | Some answers... hopefully | KBOMFG::KLINGENBERG | | Thu Jun 13 1991 13:46 | 62 |
| Hello Jim,
sorry for being late to pop up in this note, but I was off for two
weeks and am just catching up.
Yes, the ASTRO 05 shaft diameter is indeed 4mm, and, to be honest, I
wouldn't invest in a cobalt or neodymium motor with a smaller shaft
diameter. You probably already know how easily the shafts of the cheap
motors (SPEED ...) are bent. I'm not sure whether GRAUPNER offers hubs
for 4 mm shafts. If you refer to the white (glass) or black (carbon)
props from AERONAUT (designed by R. Freudenthaler), they have a
complete line of adapters, spinners and props that are (in limits)
interchangeable. I'll use an ASTRO 05 with such a prop (9*5) on my
ROBBE Kormoran. I'm not sure whether the AERONAUT 4 mm adapter would
fit into the GRAUPNER spinner, but I can check tonight. If you should
go completely AERONAUT, be aware that the adapter protrudes over the
backside of the spinner. This means that you either have to cut out
your firewall and set it ~3mm back or make up a ring to be put between
firewall and spinner (which will make it hard to find a spinner). The
front end of the UHU has a diameter of 38 mm which fits the smallest
aeronaut spinner.
I know all this because I'm just in the process to modify my UHU. I'll
try to go with the SPEED 600 FG3 (geared 1:3), and I have already spent
a few nights to get it going. I need to place the motor back into the
fuse due to the height of the gear, need an additional bearing in the
firewall and have alignment problems with motor and bearing... Oh well,
I wanted to learn, and that's what I do. In case I'll ever finish, I'll
let you know the results. My goal is to extend motor runtime (decrease
current) and flight time. Measurements on the ground indicated that
this motor has more 'ooomph' with less current than the direct drive.
We'll see.
Regarding ROBBE Arcus: It's indeed a nice looking airplane. A colleague
had one and only talks good about it (pilot's fault that it is no
more). But be aware that the fuse is plastic as is with the GRAUPNER.
It's not real fiberglass.
Comparison of motors - mmh, I don't feel competent to answer your big
question since I am experimenting, too. But the data you have given in
the table is only half the truth (if at all). There is in fact a
relation between power consumption and output (output = input *
efficiency) with efficiencies between 70 and 80 %. BUT - with an
electric, it all depends on the power supplied and the load. For
example, I have a Keller 40/10, and it is a really nice motor that will
certainly deliver 300 watts, but never with 7 cells! It is designed for
about 10 cells, and you can probably drive it with 14 cells and feed
500 watts into it. You just have to be careful for heat problems, and
you will loose efficiency when you are far off the designed
voltage/current/load. The ASTRO 05 FAI would probably not be better for
your UHU since it is optimized for pylon racing (=high rpm). This
means, you need a small prop to get a reasonable rpm on your slow (in
comparison to a pylon racer) UHU, and the efficiency of small, fast
turning props on gliders is very bad. This is why they use gears. The
efficiency of the motor is worse with the gear train, but that of the
prop is better and possibly makes it worth all the hassle. My
experiment will show whether this is true.
So much for today, hope it helps.
Best regards,
Hartmut
|
| 405.43 | Share you experience/ save others $ | USRCV1::BLUMJ | | Thu Jun 13 1991 14:43 | 44 |
| RE: -1
Thanks for the input, I must admit I am a little discouraged at the
apparent difficulty of using folding props on the the Astro motors.
Which only highlights what I have said all along - There is a lot of
information available on electric airplanes, but very little on the
use of these motors in glider aplications(ie with folding props). I
was originally attracted to the Hobby Lobby stuff because they took
some of the guess work out of it, but they have a lot of high priced
equipment. Apparently the Astro motors were designed for use with glow
engine props, I really think Astro Flight should sell adapters so their
motors can be used with the readily available folding props. This
notes file can serve the valuable function of what works well and what
doesn't in the world of electric powered gliders. I will be able to
report shortly on how an Astro 05 FAI using 7 900mah cells works with
an UHU, I will also report on how a geared Astro 05 works on a 112"
Mirage Sailplane. Up to this point I have the following
recommendations, based on real average user(me) experience:
(1) Do not buy a cheap charger, specifically the Aristocraft AC/DC
charger sold by Hobby Lobby($53.00). It works terribly from DC source.
(2) Do not buy the Graupner Power Switch 20, spend the extra $7.00
and get the Power Switch 25, it is rated at 25 amps vs. 20 amps and
does not weigh anymore. This will allow much more versatility in
motor selection.
(3) The climb of the stock UHU(particularly) on 6 cells is nothing
to get excited about. The kit and design is great, keep the weight
down and put a light powerful motor in it. At 14 oz. wing loading
this is not a beginners ship as Hobby Lobby leads you to believe.
Since a lot of electric motor/prop/glider combinations simply do not
work well it is important that some of the more experienced elctric
fliers share their experiences. Anybody want to buy an Aristocraft
Charger cheap(see what I mean)? Keep those experiences/recomendations
coming(both positive and negative).
Thanks,
Jim
|
| 405.44 | What are you calling a prop adapter | CSOVAX::MILLS | | Thu Jun 13 1991 15:45 | 12 |
| I ordered Both "compression pins" from hobby lobby. The one for
the large props and the one for the small props. I don't know if
your calling this a "prop adapter". What I call a prop adapter
is something like what comes with the astro motor with the set screw
in it. Neither compression pin fits the shaft of the astro or the
adapter. Even though after I read the hobby lobby table I thought
they did. I had to drill the small compression pin to fit the astro
shaft directly. No gaps between firewall and spinner. Hobby lobby
will sell the compression pins seperate (depending on who answers the
phone). I wouldn't go any bigger than a 8-5 on that motor in my opinion
you'll cook something.
|
| 405.45 | What burns? | USRCV1::BLUMJ | | Thu Jun 13 1991 16:48 | 15 |
| re: -1
I will bench test the motor using fuses(20,25,30 amp) to see how
much current is drawn. Based on the outcome, I will probably
order the Graupner Mini Switch 40($58, rated at 40 amps, 300watts)
from Hobby Lobby. What would burn - the wiring, the motor, the
battery? I will call Hobby Lobby to see if they sell the compression
pins today. If they do, I will try to drill them out so I may use
the 7x3 and 8x5 props I already have, if not I might order the 4mm
adapter and 9x5 Graupner prop.
Thanks,
Jim
|
| 405.46 | Sonictronics props w/ adaptors | RGB::MINER | Dan Miner, DTN:225-4015, HLO2-1/J12 (@ H11) | Thu Jun 13 1991 17:08 | 14 |
| If you buy the Sonictronics props, they come with 3 or 4 adapters
for different motor shaft diameters. I have used these props and
have been happy with them.
_____
| \
| \ Silent POWER!
_ ___________ _________ | Happy Landings!
| \ | | | | |
|--------|- SANYO + ]-| ASTRO |--| - Dan Miner
|_/ |___________| |_________| |
| / | " The Earth needs more OZONE,
| / not Castor Oil!! "
|_____/
|
| 405.47 | Forgot to look after the props/adapters, sorry! | KBOMFG::KLINGENBERG | | Fri Jun 14 1991 06:51 | 31 |
| re.: .44
The metal part that connects the prop with the motor shaft is what I
called adapter. Compression pin is more properly for the Graupner
design, but for the high rpm SPEED 500 BB RACE for example, they screw
this part onto the shaft (as AERONAUT does in general). These adapters
might be easier to drill for 4mm than the compression type.
Unfortunately, I forgot to look whether the AERONAUT 4 mm adapter fits
with the GRAUPNER folding props. I'll try to remember to find out over
the weekend. I'm sorry!
Regarding the GRAUPNER switch: I am pretty sure that the difference in
the two switches (20 vs. 25) is just the relais used. If $$$ is an
issue, did you consider to just swap the relais in the switch you have?
You might find a suitable one at any electronics store. Okay, warranty
is an issue, but before you junk the switch you have, it might be an
alternative.
If you consider other switches/controllers: Both kinds are available
with and without BEC circuits. It's your choice. I would hesitate to
use BEC with more than either 30 A current flow (collector firing),
more than 10 cells (voltage drop and heat at regulator) or more than 3
servos (current flow through BEC circuit). But if none of these limits
is exceeded and I have made sure (=bench tested) that the receiver will
have enough juice for some more time even after the controller shuts
off the motor, I very much like to use BEC and didn't have a problem
yet.
Best regards,
Hartmut
|
| 405.48 | call Astro-Flight 213-821-6242 | CSOVAX::MILLS | | Fri Jun 14 1991 12:36 | 7 |
|
I think if you run a 9x5 direct the batteries will get very hot and
possibly vent. The motor commutator and brushes may get over heated
also. With the standard astro 05 and an 8x5 my batteries get extremly
hot. You can't hold them in your hands firmly for more than a few
seconds. Call ASTRO flight and see what they have to say 213-821-6242.
|
| 405.49 | More Astro info. | USRCV1::BLUMJ | | Mon Jun 17 1991 13:44 | 33 |
| I called Hobby Lobby and they said they had just started carrying a
new adapter that allows 5mm Graupner props to be used with Astro
motors. In line with my suggestion that we share our knowledge/
mistakes regarding equipment, I have the following to report:
(1) I bench tested my father's new 125 watt, geared, Astro 05 with
Sonictronics 12x7 folding prop, 7 cell, 1100 mah SR battery which
charged with my lousy Aristocraft charger for 30 minutes @ 2.5
amps or less(the charge rate falls over the charging time). This
setup yielded a strong continuous run of 2:45. With a properly
charged battery, I would think a strong 3 minute run was feasible.
(2) The Astro Flight model 110A peak detecting charger works very
well. It peaked my 900mah SCR battery in less than 20 minutes.
(3) I received my Astro 05 FAI direct drive(200watt) and will hope-
fully bench test it this week when the Hobby Lobby adapter and
prop comes. It looks like a great motor excepting the cheap
Tamiya connectors. I think that its time these things were
phased out, at least for model airplane motors.
Hartmut is right, after talking with Hobby Lobby, the only difference
between the Power Switch 20 and 25 is the contact relays.
As a point of interest I calculated the wing loading of the US f3E
ships, and figure they are 26 oz/sq ft minimum and probably closer
to 30 oz/sq ft. They must be challenging to land!
Regards,
Jim
|
| 405.50 | ASTRO makes $35 40 amp switch | CSOVAX::MILLS | | Mon Jun 17 1991 14:47 | 6 |
| I noticed in the Tower catalog that ASTRO has a BEC switch for around
$35 rated at 40 amps !!!. And as you can see now ASTRO flight doesn't
make junk. So it sounds like a pretty good deal. That's great about the
adapter. I wonder if they just drilled out a bunch of 4mm :-). Let us
know if it's a different size compression pin or an adapter that
converts 4mm to 5mm or what ever.
|
| 405.51 | | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Mon Jun 17 1991 14:59 | 9 |
| And while your're at it Jim, cut off those Tamiya connectors and
install Sermos.
I'm waiting to hear about the Astro/Graupner combo.
I tried using a Sonictronics prop on a Graupner motor once, and
it fell off in the air. The set screw and adapter was bogus, so
I've stayed with Graupner and Aeroflite props since.
Terry
|
| 405.52 | Sand your sermos connectors | CSOVAX::MILLS | | Mon Jun 17 1991 16:41 | 6 |
| Don't forget to sand the contact with very fine paper lightly before
inserting into plastic. Solder resin or oxide can be on them and make
NO contact. I have had one refuse to make contact even after pushing it
in and out many times. Kay Fisher also had a similar problem and now no
longer likes them. But I still like them but always sand them and have
had no trouble since.
|
| 405.53 | To sand or not to sand... | RGB::MINER | Dan Miner, DTN:225-4015, HLO2-1/J12 (@ H11) | Mon Jun 17 1991 17:07 | 15 |
| I've never sanded mine and haven't had a problem. I do make sure
that I don't get any flux on the contact area. I don't think
sanding them is a good idea because they are silver plated - sanding
them will remove the silver plating...
_____
| \
| \ Silent POWER!
_ ___________ _________ | Happy Landings!
| \ | | | | |
|--------|- SANYO + ]-| ASTRO |--| - Dan Miner
|_/ |___________| |_________| |
| / | " The Earth needs more OZONE,
| / not Castor Oil!! "
|_____/
|
| 405.54 | | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Mon Jun 17 1991 17:16 | 8 |
| Yeah, I've never sanded mine either. The contact area does seem
to attract flux readily, but a good cleaning solves this.
I've never had a bit of problems with them, but wish there were
an easier method of inserting the contact into the housing without
the ~$5 tool that Sermos sells. I've never seen one.
Terry
|
| 405.55 | I wouldn't trust my $300 in the air without sanding | CSOVAX::MILLS | | Mon Jun 17 1991 23:16 | 7 |
|
Well I know of two failures Kay and Me. I swear I didn't get flux on
it but I gave sermos the benifit of the doubt. But I think it was heavy
oxide build up. When I clean them they turn from very dull to almost
like chrome. I agree the silver is very thin. That's why you should
use very fine (~300) paper.
|
| 405.56 | aeronaut/GRAUPNER don't match. What did you expect | KBOMFG::KLINGENBERG | | Tue Jun 18 1991 05:22 | 14 |
|
Real connectors for electric flight are gold plated...
Jim,
I'm happy to hear you found a suitable adapter. I had to find
out last night that the aeronaut adapter is by ONE mm (.040")
smaller than the GRAUPNER prop wants it (12 instead of 13 mm).
Not sure if it would work or if the prop would wearout easily,
I wouldn't want to try. How could I hope it would be otherwise...
Best regards,
Hartmut
|
| 405.57 | My .02 on connectors | USRCV1::BLUMJ | | Tue Jun 18 1991 10:08 | 16 |
| I like the look of the gold Konkat(sp?) conectors shown in the
Hobby Lobby and Robbe catalogs. They are about twice as expensive
as the Sermos($7.60 per pair) but look much simpler to solder well
and I think you would be able to tell if you were getting a bad
connection because they are basically high quality banana plugs
(rated for 30,000 connection cycles). Now that I have everything
changed to SErmos is probably a bad time to make this decision.
I have probably gotten some flux on my Sermos connectors, I have
never successfully been able to extract the metal contact once it
has been installed in the plastic housing. If I had it to do again,
I would use these connectors(they are rated at 80 amps, which is nice).
Thanks,
Jim
|
| 405.58 | Use a Diaper pin and a screwdriver | CSOVAX::MILLS | | Tue Jun 18 1991 15:08 | 6 |
|
I don't think twice about extracting the sermos connecters. I just use
a thick pin (diaper pin, a "T" is a little thin but it works too) on
the side to get it to clear the retaining clip and then just push it
out with a small screw driver (you have to push pretty hard).
|
| 405.59 | Astro 05 FAI test results | USRCV1::BLUMJ | | Thu Jun 20 1991 10:55 | 16 |
| My prop and adapter came from Hobby Lobby last night. I ran the motor
on the bench, here are the stats:
Motor: Astro Cobalt 05 FAI (rated 200watts)
Battery: Sanyo 7-cell 900mah
Charger: Astroflight 110A
Charge procedure @ time of test: Charged at 4.5 amps until peaked
by the 110A(approx. 18 minutes)
Prop used: Graupner 8x4.5 folding Scimitar
Lowest fuse that didn't blow: 25amp
Run time on bench with above config: 2 minutes
Regards,
Jim
|
| 405.60 | First flightAStro 05/UHu | USRCV1::BLUMJ | | Fri Jun 21 1991 10:11 | 17 |
| Last night I flew the Elektro-UHU with the new motor(Astro 05 FAI Direct
drive) and Graupner 8x4.5 prop and Sanyo 7-cell 900 mah battery. The
climb was much better than with Speed 500 or 600 which I had previously
used. Two excellent climbouts were possible. The biggest problem is
the nose comes up and causes the ship to stall. Best climb is obtained
by keeping the nose pointed approx. 20 degrees upward. This ship will
not climb on the prop alone. I am really sorry that I could not use
my Power Switch 20 BEC, the ship definitely feels heavier with the
250mah battery. I will weigh the ship this weekend and make sure the
battery is "peaked" when I fly again. The speed of this combination is
impressive! I am also going to call Astroflight to see if they feel
this combination would work with a 9x5 prop. Hopefully I will be able to
replace the standard futaba servos with s133's to reduce weight.
Regards,
Jim
|
| 405.61 | Predicting Performance | USRCV1::BLUMJ | | Fri Jun 21 1991 17:45 | 66 |
| In my quest for a poor man's F3E type glider, I will Compare(pick-on)
Hobby Lobby's offerings:
SHIP ASTRO-UHU ASW22B B270 SUNFLY SPEED500-UHU
WEIGHT(OZ) 48 112 79 106 46
WING AREA(SQ IN) 450 766 679 604 450
WING LOADING(OZ/SQ FT) 15.4 21.0 16.8 25.3 14.7
MOTOR RATING(WATTS) 200 512 144 512 120
WATTS/OZ. 4.17 4.57 1.82 4.83 2.61
RECOMMENDED BATTERY(V) 8.4 19.2 9.6 19.2 8.4
RECOMMENDED PROP 8X4.5 ? 10X6 11X7 8X4.5
What I am attempting to do is see how my UHU compares with other ships
which have received rave review both from Hobby Lobby and others, and
also to see if the numbers make any sense in predicting performance.
The above numbers are based on specifications given in the Hobby Lobby
catalog, as usual, I would expext them to be optimistic(ie your lucky
if your ship weighs in at the advertised weight).
The Sunfly was given a rave review by Model Builder Magazine, they
were really impressed by its performance in the above configuration.
This ship would cost over $1000 as listed above. The ASW22B with the
above configuration was awarded first prize for "Most Impressive
Electric Airplane" at the KRC Funfly. With all these accolades, these
would seem like the ships to use for comparision.
The first ratio I looked at was watts/oz. Repowering my UHU with the
ASTRO resulted in a 40% increase in watts/oz. and since the same prop
and battery was used , a good comparison can be made. Earlier
in this conference Mr. Mills said that the relationship between weight
and power was not linear. Empirically he is right, my UHU does not
climb 40% better with the new motor. The Sunfly has a watts/oz. rating
15.8% higher than my UHU, but then again if I put the MARX GT300/5($107
from Hobby lobby, 450 watts) my watts/oz would soar to 8watts/oz, which
is 65% better than the Sunfly. I doubt that my UHU with this motor
would outclimb the Sunfly by a large margin. I must conclude that the
manufacturer's rated watt output is not a good indicator of what
ultimate performance you can expect. This conclusion has been stated
earlier by another contributor. I must ask again - WHAT IS THE VALUE
OF THE MANUFACTURER'S WATTAGE RATINGS???? When it comes to climb, I
would think that a light ship spinning a large propeller would climb
well. The Sunfly weighs 2.2 times as much as my UHU and has a motor
rated at 2.5 times the power. Hence I would expect the climb of the
UHU to be close to the Sunfly. Conversely, the uhu with the Astro
weighs 4% more than the speed 500 version but has 60% more rated power.
Without rambling on a lot more, I think that it is obvious that using
weight and motor wattage is a bad way to predict climb rate. The
prop size must be taken into account and matched to the motor and the
glider. Short of watching someone fly a configuration, I have no idea
how to come up with this "match" without actually buying the euipment
and testing it myself. Comments welcomed?
Regards,
Jim
|
| 405.62 | F3E:A hole in the sky to drop money | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Fri Jun 21 1991 18:35 | 23 |
| Poor Man's F3E is probably an oxymoron. Aside from that, wattage
ratings give only a rough indication of what the motor can do and
is useful for comparisons between models from the same mfg.
Battery size/type is one item that must be specified before any
meaningful comparisons can be made.
Your idea of watching various types fly is the best way, if often
impractical, of narrowing down what you are willing to accept as matching
your personal price/performance profile.
Of all the electric stuff that I have bought from Hobby Lobby over
the past 3 years, it has all performed satisfactorily, and I have
developed to some degree, a feel for what a certain combination
might do. Still, I don't think that any sort of chart is going to
be a substitute for (expensive) experimentation.
It's probably no accident that most of the contest winning F3E planes
are own design/scratch built types. Their builders probably dispaired
of ever finding a kit that would do exactly what they expected.
Terry
|
| 405.63 | Winning Combinations | USRCV1::BLUMJ | | Mon Jun 24 1991 12:41 | 36 |
| Re: -1
Yes poor man's f3e certainly is an oxymoron, but it is a lot fun
trying anyway! At this point, I am only considering the power
aspect. The really hard stuff is how to build 2-meter wings that
can support an all up weight of 7lbs. flying at speeds over 100mph,
doing pylon style turns(high G's) and still fly power off for 5
minutes and spot land. Now that is going to take some $ and a lot of
engineering skills. I think that f3e offers the designer more
challenge than any other type of RC competition. So it is fun to
see how fast I can make a small, 7-10 cell ship climb, and how fast it
can fly. The Uhu has been a great place to start, with the ASTRO 05
FAI, it has a good climb rate, its low drag allows it to fly quite
fast, and the price tag for this setup with Astro 110A charger is less
than $400(excluding radio gear). I have a set of Balsa USA Allure
plans coming(2 meter, 632 sq.in, 9% airfoil, V-tail with ailerons)
which I will evaluate for a next project. This model powered by a
Keller 520 watt competion motor, spinning a 12-6, using 10 cells would
have a comparable wing loading to the Uhu at twice the watts/oz.
rating. The total cost for this setup is: Allure plan + materials
$30, Keller motor-$249, Astroflight Speed control $139, 10 cell 1100mah
SR battery pack-$65, Astroflight 110A charger $82, Frudenthaler 12x6
prop- $27 = $592. Throw in a vision radio and you just spent about
$1000! For the sake of argument lets call the upper limit of "poor
man's f3e" $1000.00, including all necessary equipment(charger, speed
control, servos, etc). Anybody got any winning combinations in mind
that fit this criteria? This is a challenge compared to most
electric flight I have read about. If you build a light 2 meter
thermal duration style glider(ie Spirit, Electra, etc.) and power it
with a geared 125 watt motor using 7-cells, I don't think you can miss
having a winning combination. A winning combiation for "poor man's
f3e" is going to be more difficult to achieve.
Regards,
Jim
|
| 405.64 | Astro 05 props | USRCV1::BLUMJ | | Fri Jun 28 1991 19:43 | 10 |
| I called Astroflight and asked them about running a 9-5 prop on my
Asto 05 FAI, they thought it would get pretty hot, but would probably
be ok for 30 second runs. He really thought the 8-4.5 was about the
best so I will stay with that. They mentioned that they are coming out
with a 15 FAI that will be rated at about 400 watts. Hopefully we will
be seeing this motor soon.
Regards,
Jim
|
| 405.65 | Electrified Mirage Report | USRCV1::BLUMJ | | Mon Jul 01 1991 10:31 | 24 |
| This weekend my father flew his electric converted Mirage sailplane.
The specs are:
(1) Mirage polyhedral sailplane, 112" wing, all up weight 58 oz.
(2) Motor - Astro flight 05, 125 watt geared motor
(3) Battery- SR 7 cell, 1100mah
(4) Charger - Astroflight 110A
(5) On/off Switch- High Sky rated at 25 amps
(6) Prop - Sonictronics 12-7
The Mirage flew very well with this setup, the climbout was good,
allowing two climbs to higher than winch launch height. The wing
loading of this ship is about 9.5 oz./sq. ft.(*it was a real floater
before electrification) so it still thermals very well. In poor lift
conditions flights of 15-20 minutes per charge were attained. Recharge
time is 18 minutes. I was surprised to see this big, rather draggy(by
modern standards) sailplane climb so well with the Astro. I am really
sold on electric, it is expensive, to be sure, but your stick time
really increases and you can fly alone.
Regards,
Jim
|
| 405.66 | F3E World Competition | USRCV1::BLUMJ | | Tue Jul 02 1991 15:40 | 13 |
| I was reading the review in Model Builder magazine of the F3E world
championship. The top climbing glider went up at a rate of over 6000
feet per minute. This equates to climbing at 68 mph! At this rate
the motor runs are typically less than 20 seconds. The winner, Rudolph
Freudenthaler, averaged 115 mph in the speed event. I would really
love to see a competition of this caliber. The American team turned in
an excellent showing, finishing in second place, it appears however,
that this type of flying is concentrated in California.
Regards,
Jim
|
| 405.67 | New electrics in Model Builder | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Wed Jul 03 1991 11:48 | 11 |
| Jim,
Did you notice in the latest issue of MB, that Freudenthaler is
selling a small F3E plane now ? Can't remember the name, but it
looks to be ~60-70" span. This is about the size that the guys in
Calif. are flying in the 7 cell F3E events.
I'll bet Hobby Lobby starts carrying this bird. It looks like a
good way to explore F3E flying without mortgaging the farm.
Also, how about that electro-Uhu with the solar cells in the wing.
Definitely a farm mortgage for that one.
Terry
|
| 405.68 | More F3E Ideas | USRCV1::BLUMJ | | Wed Jul 03 1991 12:14 | 16 |
| An interesting and encouraging statement from the same MB review
"no competitive flyer was using rudder control"(elevator&ailerons
only). It went on to state that the weight savings of no rudder
contributed to better climb. So if the best in the world can perform
without rudder, I certainly see no reason to add it- saves
weight,hassle, and money. Simple is usually the best way to go.
My currrent electric aspiration is to buy a Robbe Arcus and install
a computer radio(Infifnity or X347), powered by a Keller 520 watt
10 cell competion motor. This is an expensive setup, but I hope the
performance(ie speed and climb) will be spectacular. Its just tough
to spend the money with layoffs happening in my office as I write this.
Regards,
Jim
|
| 405.69 | Comments on Arcus and F3E | KBOMFG::KLINGENBERG | | Wed Jul 03 1991 13:26 | 30 |
| Jim,
the ROBBE Arcus is certainly a nice ship. A colleague had one and liked
it a lot. He flew it on 10 cells with a geared el cheapo motor ( I
think the one ROBBE recommends for 7 cells), and he said it had great
performance. The only drawback I recently heard of is that it likes to
tip-stall. So, make sure you'll keep the necessary airspeed.
Omitting a control in order to save weight is very common with
electrics. I just read an article the other night about a semi-scale
contest for electric planes here in Germany. The class was called
400/10, meaning the planes were supposed to have a scale of 1:10 and
cheap motors (GRAUPNER SPEED 400, Mabuchi 380 etc.). Some very nice
planes. Some of the big ones (4 or even 6 SPEED 400 motors), even with
0� dihedral, flew without aileron. The relation between wing stiffness
and fuse weight is such that it has enough dihedral in the air to give
sufficient control by rudder only. These guys really know how to build
light! Sorry, this doesn't really belong into the F3E note, I just had
to tell you...
More on the F3E side: I had a chance to watch a F3B contest the other
weekend with some of the best pilots Germany has (part of German
championship). It was IMPRESSIVE, especially the zoom launches and the
speed flights. Now if you consider that F3E ships have a ground speed
for distance flights that is similar to that of F3B speed flights -
it's certainly an event to watch! And a hole in the sky to drop money
(and all kind of material) in...
Best regards,
Hartmut
|
| 405.70 | Electric Fiesta | USRCV1::BLUMJ | | Wed Jul 03 1991 13:54 | 13 |
| re: -1
Hartmut,
How is the performance of you elctrified Fiesta? If I get a
computer radio, Iam thinking of finishing my Fiesta with electric
power. You mentioned earlier it uses a Keller 40/10 with 12 cells.
Does this give it enough power for good climb. What is your
impression of Keller motors in general?
Thanks,
Jim
|
| 405.71 | FIESTA and Ke 40/10 | KBOMFG::KLINGENBERG | | Wed Jul 03 1991 14:24 | 46 |
| Uh oh, you finally got me...
I'm sorry, can't really say much. I tried the concept last year with
just two flights and it seemd to be fine. The climb rate was better
than that of my UHU (with Speed 500 7.2V/8*4.5 folding prop/6 cells
1200 SCR). Unfortunately, the flights weren't very long because of dead
air and the batteries weren't used for a few weeks. It was just enough
that I decided to leave it as it is and give the fuse it's final
colour.
The weather didn't cooperate for spraying, than we moved our house... I
just managed to get the FIESTA E done last weekend. I wanted to fly it
Monday, but got a chance to fly full scale. So it's still in the shop,
but ready for flying again.
The one thing is: it's pretty heavy and therefore, fast. Multiplex
makes a kit now for an electric FIESTA, and they offer it with an ASTRO
cobalt 05 (geared, but not ASTRO gear) and claim it flies on 8 cells.
It's probably quite different, more on the soft side.
I expect to get even better climb rates with a carbon prop I hope to
receive from Ed Siegmann. I'll keep you posted. But one thing I can say
for sure: making an electric of the FIESTA wasn't easy - at least for
me. It took A LOT more headscratching than the aileron servos - you
know what I mean... I put two 6cell battery packs right behind the wing
steels into the fuse, and the radio stuff as far back as possible. It
still came out noseheavy - so much for the weight of the Keller 40/10.
The Keller motors in general are fine. They are - as far as I can tell
- of good quality (forget about the 540 series with the small shaft
diameter), and I like especially that at least the small ones are fully
encapsulated (good against EMI and dirt problems). The pain with Keller
is availablity. He seems to build some when he needs money and sells
most of them personnally at the contests he attends. That didn't
improve much with Robbe taking over his facility. Therefore, most
local shops prefer to carry Graupner ULTRA series which is readily
available, of comparable quality, and there is a nice price war on
(good for the customer, you can get a motor with a 20% discount which
is VERY uncommon in Germany.
Hope this helps some, gotta go home now.
Best regards,
Hartmut
|
| 405.72 | Electric throttles and Visions | KAY::FISHER | Stop and smell the balsa. | Wed Jul 03 1991 14:31 | 18 |
| > How is the performance of you elctrified Fiesta? If I get a
> computer radio, Iam thinking of finishing my Fiesta with electric
> power. You mentioned earlier it uses a Keller 40/10 with 12 cells.
By the way Jim - one of the things I didn't like using my Vision for
was an electric sail plane. It drove me nuts for a few reasons but
the main one that comes to mind at the time is the flap stick just doesn't
work as a throttle. For instance the trim always effects both the
idle and the top end (after all there is not throttle in a Vision).
When I tried to use the flap stick for a servo and switch (not a
proportional speed control) I had a problem with flap(throttle)/elevator
mix. Because the engine would be either on or off the but elevator
compensation I wanted to dial in was proportional to where the stick was.
Bye --+--
Kay R. Fisher |
---------------O---------------
################################################################################
|
| 405.73 | Reliving past ordeals | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Wed Jul 03 1991 15:04 | 18 |
| I'll agree with Kay, the Vision is overkill for electric sailplanes.
I use my Vanguard for electrics, much more straightforward, and
before that the F-word Conquest.
What Hartmut says about electrifying the various large German gliders,
AMEN !
I electrified a Graupner ASW-22 ~ 3 years ago, the cheaper one
with the built-up wing, and it was the most aggravating control/motor/
batt. installation ordeal I've ever been through. I finally wound
up reconfiguring the motor batt. into a long stick, each cell behind
the other, in order to get everything to fit and balance properly.
If the plane is engineered from the start as an electric, ie, the
Uhu, no problem. But engineering an electric installation in a plane
not designed for it, is a character building excercise you won't
soon forget.
Terry
|
| 405.74 | F3E continued | USRCV1::BLUMJ | | Wed Jul 03 1991 16:19 | 26 |
| Re: -1
Jamming all the electric stuff into any sailplane sure is frustrating!
I "need" a computer radio for electric because nearly all the high
performance models require wing mounted aileron servos in skinny
airfoils and recommend "mixing" the ailerons to become airbrakes,
so these things can be landed.
I would really like to hear any high performance electric
experiences/observations. I really don't have much to go on.
I called Astroflight today and inquired if they sold a BEC/on/off
switch(Tower Hobbies catalogue made me beieve they did). Well they
do not, and further they don't recommend the use of BEC. However
a 250mah battery weighs at least as much as 3 futaba s133 servos. If
the pros are eliminating rudder control to save weight, eliminating
a 250 mah battery pack should really help. There are always risks
when high performance is the goal. My Uhu with two standard servos,
On/Off switch, and 250 mah battery currently weighs 50 oz. I will
be reconfiguring with micro servos and go back to BEC and see what
performance gain a 3+ oz. reduction will make.
Regards,
Jim
|
| 405.75 | F3E and conflicting requirements | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Wed Jul 03 1991 17:07 | 29 |
| re .74
You've got yourself in a real bind here, Jim. As I understand it
you need/want to:
Eliminate the rudder to save weight, but this requires ailerons.
Ailerons require separate servos, but this requires a radio
with flaperon mixing capabilities for airbrakes.
Without going to a computer radio, the only solution I see is to
add another servo for coupled flaps, and reflexing the flaps up
>30 degrees for speed brakes. This works better than reflexed ailerons
but you're stuck with more weight.
I've never heard of a commercially available BEC that can handle
more than 7-8 cells. I've never heard of any serious F3E types who
would consider using one even if it were available for big packs.
Frankly they scare me, a personal prejudice.
The extra batt. weight is pretty small considering the high wing
loadings of the typical F3E plane.
I've used 180 mah Panasonic batteries for my rcvrs. They weigh ~50
grams, about two s-33s. I use them for ~ 20 minutes and then swap
in a fresh one. They give ~25 minutes in the green on my ESV at
200 ma load.
Terry
|
| 405.76 | F3E and BEC - personal opinion and reasoning | KBOMFG::KLINGENBERG | | Fri Jul 05 1991 09:53 | 36 |
| *** RATHOLE ALERT *** RATHOLE ALERT *** RATHOLE ALERT*** RATHOLE
I'll try to keep out of a possible rathole, but
1.) There are controllers for 12 or maybe even more cells on the
market (at least here in Germany) that include a BEC circuit.
2.) Their limitations are a) number of cells (the more cells, the
more must the voltage controller eat up ---> temperature and
stress for the circuit) and b) number of servos to be fed,
usually limited to 2-3. In fact, it is not so much the number of
servos, but the required current that the circuit is able to
handle.
I personnally have two controllers, one with BEC circuit, able to
handle 30/40 A (40 for very short time, this is btw a very new SMT
piece of art), and one with switchable (!) BEC circuit and switchable
EMF brake. As long as I fly with 6 or seven cells, keep the current of
the motor below 30 A (firing of brushes increases with current) and
only have to serve 2 or 3 servos, I prefer BEC since I didn't have any
problem yet (make sure by bench testing that you have enough juice
to fly some more time after the motor was shut off by the controller)
and I trust the battery that is fully charged for each flight more than
those very small packs.
As soon as one of the limitations above doesn't apply, the additional
weight for a RX battery probably doesn't hurt much. I even have a 600
mAh pack in my FIESTA electro.
But, as stated before, it's up to your decision. For the real F3E class
(27 cells, current up to 60+ A, at least 5 servos etc.) it is obvious
that you can directly throw your ship in the trash can before trying to
fly it with BEC. You will save a few minutes...
Best regards,
Hartmut
|
| 405.77 | Italian experience | VARESE::SIEGMANN | | Fri Jul 05 1991 12:58 | 30 |
| Re .70 etc on motors..
I have been having very good performance using the Keller 40/10 with 12
1200mAh cells in a 2kg (4.4#) machine. RG15 airfoil (1 mm hard balsa
coverec poly foam, covered with 18gm/mtr fiberglass/epoxy) with a 90gm
fuse, t-tail, ailerons (servos in wing) and elevator only. Using a 40
switch/brake (thanks Hartmut... ps. Hartmut: will send new prop next
week when I get from builder) and 250MaH batt. I get >30 mins on the
rcvr batt easily). Span is ~2Mtr � (I had a mid-air with another F3E
due to fooling around dog-fighting... but managed to lose only 6" off
one wing and aileron. Managed to set trim to compensate and continued
flying. May cut 6" off the other wing (-;.. great speed increase and
only marginally more difficult to land in one piece. Does eat up the
nylon wing bolt though..). Great aerobatics too for diversion and quite
competitive (still a better machine than I am a competitor) with the
other guys here (but I do cheat and use 12 cells.. so in a different
category (F3E unlim== max batt weight of 1.1kg= ~27 900Mah cells) vs.
F3E FAI (10 cells max). However it is a blast and a challenge to fly!
and the Keller seems unbreakable...(thanks again to H.K.).
Incidently Jim Blum: I am in the states July end and have an extra
40/10 which I would be willing to part with as I don't need 2. Let me
know (varese::siegmann).
I have also used the 40/10 in a 3mtr 2.5 kg glider with good success,
14 cells but switched to a Keller 80/6 as I wanted more
speed....spoiled I guess (-; .
Ciao e buon volante! Ed
|
| 405.78 | UHU REWORK | USRCV1::BLUMJ | | Mon Jul 08 1991 14:12 | 33 |
| Well I flew my UHU with micro servos and reinstalled my Power Switch 20
BEC, in place of the mini-switch 40. This brought the weight down to 46
oz. from 50 oz., the difference in performance is unbelievable. This
ship really climbs out now, I would estimate about 1000 ft. per minute.
It is hard to believe that a 4 oz. weight reduction could make this
much difference! If I twiddle the sticks properly, I get 2.5 really
high climbouts. Another problem surfaced this weekend, the torque
of the AStro 05 FAI in conjunction with Graupner 8x4.5 prop is bending
the screws which hold the prop blades to the hub. I have gone to a
Graupner 7x3 prop to see if this helps and check out the performance.
If this does not work out, I will try a Fruedenthaler 8x5 setup.
Speaking of Freudenthaler, Aeronaut will be kitting a model called the
Surprise, which is purported to be similar to his F3E ship. I called
Hobby Lobby and they can special order it, but do not expext them to
ship until September at the earliest, price is $250-$270.
The new MB magazine covered the Nurenburg Toy Fair, where electrics are
really coming into their own. Multiplex is supposed to be offering
electrics now as well as Simprop. The new RCSD magazine also tells
of a slew of companies jumping into electric.
This weekend I was able to stay up for over half an hour with my Uhu,
which included a lot of loops and general messing around. My father
was able to stay up 45 minutes, before a thunderstorm forced him down.
Getting his 112", 56 oz. Mirage down in this strong lift was a real
problem(no spoilers). Using the motor to get up into the strong lift
allows one to fly a wide variety of ships, from floater to Foam and
glass scale types.
Regards,
Jim
|
| 405.79 | sounds great | CSOVAX::MILLS | | Mon Jul 08 1991 18:16 | 7 |
| Told ya so, Told ya so, Told ya so :-)
Your ALWAYS over weight with electric and micros, as expensive as
they are, are probably the easiest/cheapest way to loose weight.
Are you sure it's torque that caused the screws to bend, that's
hard to believe.
|
| 405.80 | Robbe Arcus on the way | USRCV1::BLUMJ | | Tue Jul 09 1991 11:36 | 17 |
| After some deliberation, I ordered a Robbe Arcus. The price direct
from Robbe in NJ was $159.95. I considered the Graupner Cherry which
Hobby Lobby sells for about $230, however this model is essentially
prebuilt. I like the fact that Robbe sells wings, empennage, and
canopy all separately which is nice if the model is damaged. I will
report on the kit quality and ease of building. The wing is a 2 meter
built up, employing a transitioned airfoil, Eppler 178-180. The
fuselage is blow molded Plura, with molded in fin. The estimated
wing loading with 10 cells is 18 oz/sq ft. I want to see the fuselage
before deciding on a motor. Iwould like to use the new Astro 15 FAI
direct drive if it will fit and I can get one. I am hoping this will
be a real fast machine. Now to spring for a JR X347, to fly it!
Regards,
Jim(who's going
broke)
|
| 405.81 | WORLD'S EASIEST TO FLY RADIO CONTROL PLANE | HPSRAD::AJAI | | Tue Jul 09 1991 12:16 | 48 |
|
Here is the ultimate F3E machine, pulled out from one of
the junk mail catalogues that I received...
WORLD'S EASIEST TO FLY RADIO CONTROL PLANE
Guaranteed Against Crashing!
Fear of flying? We'll get you through your learning
period, the first 60 days. Should any part break, the
manufacturer will repair or replace it for only a small
shipping/handling fee. There is no ELECTRIC WIRELESS
RADIO CONTROL plane more complete or read-to-fly! Tough,
modular construction. Snap on & align the wing, tail &
battery pack & you are ready. Even beginning fliers can
perform ground takeoffs & landings. Quick lift wing
structure allows you to fly in small fields or parking
lots. Remote motor on/off for power gliding give greater
flying time than any other electric airplane. UP TO
2000' RANGE. Safe, clean & convenient. No messy fuels.
No noise pollution. No hot gasoline motors. Simple
battery pack is charged in only 18 m inutes from car
cigarette lighter. Includes transmitter, battery pack,
charger, extra parts, crash warranty & instruction
manual. 34" wing span. Please allow 4 to 5 weeks for
delivery.
Cat # T-765 RC Plane ...........................$199.00
Order from :
JOHNSON SMITH COMPANY
4514 19th Court East
P.O.Box 25500
Bradenton, Florida 34206-5500
Phone: 813-747-2356, 8:00- 4:00
With all this talk about $350 JR radios, and $150 Robbe
planes, and $50+ chargers, are you sure you guys have
your act straight? Besides, you don't even have a crash
warranty to boot!
:-) :-)
ajai
ps: The pix in the ad looks like a Cessna 150, and has the
name SKY WALKER on it.
|
| 405.82 | Your choice of 27.045 or 27.095mHz (CB band) no doubt | ZENDIA::REITH | Jim Reith DTN 226-6102 - LTN2-1/F02 | Tue Jul 09 1991 14:24 | 5 |
| I buy the plane of my choice with my Citibank Visa and they replace it
in 90 days no matter HOW stupid I act. Citibank Visa - when I'm feeling
irresponsible!
Gawd, I hate those ads.
|
| 405.83 | Astro 15 FAI available | USRCV1::BLUMJ | | Fri Jul 12 1991 09:52 | 12 |
| I ordered an Astroflight 15 FAI motor from CS supply in Massachusetts,
last night. He is the only one I have found who has these in stock.
The cost was $129.95 - 15% + $5.00 shipping & handling. This motor
is Astro's entry into the highly competitive and hereto European
dominated 10 cell class. I will probably put this motor in my new
Arcus(assuming it will fit). I am not sure what prop to use, Astro
recommends an 8x4 in their product description, I probably will try
a 9x5. Hoping to receive the Arcus in the next few days.
Regards,
Jim
|
| 405.84 | Initial Arcus kit impressions | USRCV1::BLUMJ | | Wed Jul 17 1991 17:34 | 16 |
| The Robbe Arcus kit arrived, my initial impressions are it is a quality
kit. The foam wings are presheeted, which surprised me, considering I
expected them to be built up! What was disappointing is to install
a direct drive motor requires cutting off the front of the plastic
fuselage and glueing in a plate of your own fabrication. Doing this
with the proper amount of down and side thrust will be a challenge.
I wish they did it like my UHU kit which assumes the kit will be
electric powered and requires gluing on a provided nosecone if it
is to be use as a glider only. Getting 10 cells in this fuselage
wll also be a real challenge. I am hoping to install my newly
purchased Astro 15 FAI motor. I will give final impressions on
completion of the kit.
Regards,
Jim
|
| 405.85 | F3E/F3B Speed task | USRCV1::BLUMJ | | Thu Jul 18 1991 17:25 | 15 |
| Can anyone tell me how the top F3E flyers are able to average 115mph
(26 laps around a 150m course). I assume it is similar to F3B, but
never having seen either competition, I am not familiar with how
it is done. Do they enter the course at very high altitude and then
essentially fly in a DOWNWARD SPIRAL around the pylons,
killing say 1000ft. of altitude over 26 laps? I have been trying to
fly my UHU as fast as possible, but am sure that it is not going any
where near 100mph. Has anyone seen high caliber f3e or f3b flyers
perform the speed task and can comment?
Thanks,
Jim
|
| 405.86 | Speed and distance are separate tasks | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Mon Jul 22 1991 11:29 | 27 |
| Jim,
I think you're confusing the distance with the speed event.
The 26 laps would occur during the distance event, and average speed
would be far lower than 115 mph since they are trying for max L/D.
The speed event is only 4 laps for the lowest elapsed time.
In both events they would enter the course as high as possible,
but would be more concerned with height for the distance event.
I spent 3 days helping run an F3B event over the 4th weekend, and
the entrants were very fussy about gaining at least 1500-2000 ft.
before entering the gate for the distance event. They would relaunch
instantly if things were'nt exactly right.
For the speed event, the altitude from a good launch was all that
was needed (~1000 ft.) 600 meters and 3 turns later, they would
be down on the deck (3-8 ft) and whistling out the gate at 120+.
Turning technique is 90% of the speed run.
19 seconds was the fastest time during the contest. 31.57 meters/sec.
103.6 ft/sec.
Terry
|
| 405.87 | How far is a lap? | USRCV1::BLUMJ | | Mon Jul 22 1991 14:53 | 20 |
| Terry,
I probably got things confused by speaking of F3B and F3E in
399.85. The task in F3E combines duration and distance(you probably
know all this). The distance portion of the task requires the
contestant to complete as many laps around a 150 meter course as
possible in 3 minutes. It is my understanding that typically 1 min-
ute is used for climb and 2 minutes for completing the laps. The best
flyers comlete 26 laps, what I am not sure of is whether a lap is
150 meters or 300 meters. If 1 lap = 150 meters, then the average
speed is approximately 73 mph, if 1 lap = 300 meters then the average
speed would be 146 mph. The 115 mph figure I quoted came from a
magazine(MB, I believe). At any rate, they equated the speed to F3B
contests. The figure you quoted af 103 ft./sec equates to approx. 70
mph. I would appreciate it if someone could clarify what a "lap" is
in F3E.
Thanks,
Jim
|
| 405.88 | F3B/F3E distances & terminology | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Mon Jul 22 1991 15:37 | 21 |
| In F3B a lap is one leg of the course. One round trip from the start
line to the far turnaround and back is two laps, 300 meters. This
is confusing but that's the way it is.
I suspect that F3E rules are the same and the numbers bear this
out.
In F3B, 4 legs/laps ,ie, 2 round trips constitute the speed task.
These must be completed within a 2 minute working time
The distance task is as many legs/laps as possible in 4 minutes,
within a 6 minute working time.
Typically the distance task starts off with the planes flying fairly
slowly for best L/D, then as the end of the 4 minutes approaches,
they speed up until the last few legs resemble a speed run.
Standing at the far turn around doing sighting/signaling can be
rather exciting as those babies stand on a wing tip and whistle
around your head.
Terry
|
| 405.89 | I watched a recent F3B contest in Munich | KBOMFG::KLINGENBERG | | Tue Jul 23 1991 12:20 | 35 |
| Re: F3B/E events
A few weeks ago, I had a chance to watch a B-Kader F3B contest in
Munich. I was invited by Hans Karnitschnik (another noter) and was
really impressed. B-Kader contest means that the winners of a series of
these contests are the A-Kader which is the national team. So, all
great names in Germany were there, Ralf Decker, Reinhard Liese, Klaus
and Martin Weberschock, Martin Kowalski etc. The workmanship of the
planes was just great, it took me some time to get my mouth closed
again.
Most impressive to me was the zoom launch. I read about it before, but
it turned out I had NO IDEA what it relly looked like. I could barely
believe what I saw: A glider going about 100 m straight up after
popping off the line! Then slowly going to the A-line and turn into the
course at high speed. Speed event is the first I saw. All the great
height (that would keep these planes up for 6+ minutes without
thermals, as the later duration event proved) was gon after 20 seconds
when the planes finished. This means - for the good ones - less than 5
seconds for 150 m plus turn! Average speed (including turns again) is
108 km/h here (67 mph). The other events are interesting, too, but not
that much breathtaking. The landing after duration was new to me, too.
Duration means 6 minutes exactly with landing at a line. The line was
20 m behind the row of winches, but I think not one plane missed it by
more than 5 m. I remember trying to land less than 50 m away from the
line when I attended contests...
The equipment that gives the plane the high speeds (besides the clean
aerodynamics) is ballast weight. And F3E planes carry a ballast
(battery) of 1.1 kg! Therefore, the speed of an F3E plane during
distance event is not far from taht of an F3B plane flying the speed
event. Should be even more impressive. And expensive, of course.
Best regards,
Hartmut
|
| 405.90 | | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Tue Jul 23 1991 13:07 | 18 |
| re .89
Interesting report Hartmut.
I wonder what type of winch line the Germans are using now ?
Over here, 200 lb.test, nylon monofilament has become the standard.
It has plenty of stretch; Hold down the winch pedal until the motor
is nearly stalled, then heave 'er out and kapowie !, an instant
100+ meters of altitude.
Audi starter motors are popular because they have the correct internal
resistance to meet the rules without a lot of experimenting with
external resistors, however Honda starter motors are thought to be
the most desireable, if you don't mind doing the resistance calculation
excercise.
Terry
|
| 405.91 | They use nylon monofilament here, too | KBOMFG::KLINGENBERG | | Tue Jul 23 1991 14:43 | 41 |
| Terry,
your description of the start method is exactly what I saw, only I
couldn't describe it as well, so I left that part out. They nearly
stall the winch and then let go. In fact, there was a girl at this
contest that helps the SAF team (Martin Weberschock, Klaus and Peter
Kowalski). Rumor has it, that it's her influence that the planes of
this team have a special art design. If you consider that all the
painting for the wing must be put into the negative mold, the planes
with fall edition (with leaves), desert edition (cactii, sand and dark
blue sky with some elephants and vultures) it's a lot of additional
work, but it does make a difference. Hans told me that during less
important contests, she sometimes starts the planes. She must attend
aerobic courses or whatever, her back bows until the tail feathers are
close to touching ground before the winch is about to stall and the
plane is released.
I assume even the winches are about the same. As far as I know, Ralf
Decker (who is in the BOD of the Munich club that held the contest)
took the initiative some years ago to limit the winch power (by giving
a minimum internal resistance) and got this introduced into the
international rules.
The line that is used depends on the wind (as well as the winch drum
diameter). I happen to have a few inches on my desk of a line that was
ripped apart during the contest. It's a 1.4 mm (.055") monofilament
nylon line. I always wanted to test it on our tensile strength tester,
but didn't make it yet. Im pretty certain that it will at least hold
200 lbs. I assume this kind of line is chosen not only because of it's
strength, but because of the elasticity as well. There is a lot of
energy stored in the line at the moment the plane is released.
Unfortunately, these all composite planes are expensive (the winner of
the contest flew a ship you can buy for 1395 DM (~$ 800)). They would
be nice to fly as a glider. They are easy to handle (you can't use
planes in a contest that are hard to fly) and - for a common R/Cer -
practically unbreakable. And they still have amazing sink rates/glide
ratios. If there wasn't this darn price tag...
Best regards,
Hartmut
|
| 405.92 | JR Servos | USRCV1::BLUMJ | | Fri Jul 26 1991 09:53 | 19 |
| My JR X347 arrived last night. I was comparing the NS321 servos that
came with it to the wing thickness of my ARCUS. A lot of the servo is
going to be sticking through the bottom wing skin. The kit provided
molded "shells" to cover up wing mounted servos, but it sure is going
to be ugly and probably draggy. This ship with its 18+ oz./sq. ft.
will need help slowing down to land which is why I wanted to program
the ailerons to work as air brakes. I am new to JR equipment and
am not familiar with their servo offerings. The NS321's are larger
than Futaba S133's. The February issue of Model Builder talks about
JR micro servos with metal gears, model #305m. The place where I
bought my radio said this model was discontinued. Does anyone know
if JR makes micro servos with metal gears? I would like to see a
world class F3E ship's wing servo installation, to see how far the
servo's protrude through the wing. I wonder who sells the smallest
servos suitable for aileron control?
Thanks,
Jim
|
| 405.93 | Nothing shows on the winners.. | PIPE::SIEGMANN | | Fri Jul 26 1991 11:28 | 8 |
| Ciao Jim: The winners in this class actually bury the servos in the
wings as well as all the aileron linkages! They run the control rod
through the training edge and connect to a piece of plastic/whatever
imbedded and off-set (vertically) into the aileron (ie. located below
the center of the aileron).
Ciao, Ed
|
| 405.94 | | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Fri Jul 26 1991 12:22 | 11 |
| As Ed says, there are no exposed linkages, servos, horns, etc. on
any serious F3B/E ship.
I've used the JR 305's, not the metal version, and they would very
likely fit in an Arcus wing totally. If you can find some 305's,
even the non-metal ones, I think you'd be ok.
Since I'm stopping by the hobby shop tonight, I'll see if they can
verify the 305m non-availabiltty story.
Terry
|
| 405.95 | Wing Servo Mounting | USRCV1::BLUMJ | | Fri Jul 26 1991 13:21 | 15 |
| Where is the best place to locate a servo horn on the aileron? I
would think it would be in the middle of the aileron(ie if the aileron
is 12" long, the horn should be at the 6" mark). The futaba S133 servo
is just under 1/2" thick without a control arm attached. I think the
ARCUS wing is less than 1/2" thick at the point where the servo would
be buried(assuming my idea about locating the servo horn at the
midpoint of the aileron is correct). I did notice in a magazine a
picture of the bottom of Rudy Freudenthaler's wing, and he had little
plastic shrouds glued on, presumably to cover the servo control arms.
Regards,
Jim
|
| 405.96 | Inboard will work | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Fri Jul 26 1991 14:26 | 9 |
| Ideally the servo horn should be in the middle of the surface, but
rarely is, and if it came down to putting the servo in the middle
and not having it buried or putting it on the inbd. end and having
it buried, I'd go with the inbd. mounting every time.
If flutter is going to occur it will be for other/more reasons than
just where the horn is located.
Terry
|
| 405.97 | Awesome PErformance!! | USRCV1::BLUMJ | | Mon Jul 29 1991 11:15 | 25 |
| Over the weekend I was reading through some old magazines, and I came
across Don Edberg's report of the 1990 F3E team trials in RCM. I found
out some interesting things, one being that the elevator servo is
mounted directly in the fin of the glider. With the aileron servos
mount in the wings, this leaves room to stuff all the batteries in the
fuselage. Also Don stated that on at least one round, Jerry Bridgeman
was able to fly under the 3 meter gate with so much speed that his
subsequent climbout for the duration portion of the task required no
motor run! His average motor run for duaration was 3.5 Seconds!
Well thinking this sounded really neat- being able to swoop down to
ground level and then climb out without power for a 5 minute glide, I
figured I'd see how close I could emulate this with my trusty Graupner
UHU. It was basically a bust. I would dive the UHU down from maybe
150-200 ft. and during the pullout I was lucky to get back up to 50 ft.
I think the biggest reason for the lousy climbout is the wings flex
quite a bit hence, robbing much of the energy needed for the climbout.
I also suspect the Uhu is somewhar draggier than those world class
ships. My Arcus will have a higher wing loading and a One piece foam
wing sheeted with balsa. I will be curious to see if this will
increase the power off climbout. Are F3B ships able to climbout like
this, or do the longer wings flex too much?
Regards,
Jim
|
| 405.98 | A few F3B/F3E differences | ELMAGO::TTOMBAUGH | A Fistful of Epoxy | Mon Jul 29 1991 11:46 | 24 |
| There are a few differences in F3E & F3B rules that make it hard
to directly compare them, however:
F3B wings don't flex, within any normal meaning of the word, so
given the same speed, and wing loading between a typical plane of
both types, climb-out performance would be similar.
F3B tasks are separated by launches,ie, one task does not flow into
another without landing and relaunching, so you would never see
the type of flying described by Jim in .97.
There are no altitude restrictions in crossing the gates in F3B,
in any task. The 9 meter height limit in F3E is necessary to insure
that every competitor starts at the ~same point at the beginning
of duration. In F3B this "same point" is defined as how high you
can get off the winch and then thermal up as much higher as possible
during the working time.
Over generalizing just a bit, F3B depends on thermal soaring
performance to a greater degree than F3E, in the duration and distance
tasks, while F3E depends more on velocity, inertia, and the altitude
gaining effects of these factors.
Terry
|
| 405.99 | Astro 05 w/ Freudenthaler 9.5-5 | USRCV1::BLUMJ | | Fri Aug 23 1991 12:04 | 14 |
| To continue on electric combinations that work/don't work, I tried
a Freudentahler 9.5-5 Carbon fiber prop on my Graupner UHU with
Astro 05 FAI. The RPM was significantly reduced, but the climb
was as good or maybe a little better than with the Graupner 8-4.5
prop. The motor and battery however got unacceptably hot, I do not
recommend a prop bigger than 8-5 with the Astro 05 FAI. I find the
Freudenthaler props/assemblies to be much sturdier than the Graupner
and highly recommend them.
Regards,
Jim
|
| 405.100 | Aeronaut Sunfly/Weston Waco | USRCV1::BLUMJ | | Wed Aug 28 1991 14:50 | 18 |
| The new Model Aviation certainly had a favorable review of Aeronaut's
Sunfly(available from Hobby Lobby). I was really impressed with Byron
Blakeslee's report on this ship. Interestingly enough, Frank Weston
of Weston Aerodesign fame, claims this ship flies like a dog compared
to his 38 oz. Waco 570 on 7 cells. Frank feels that the future of F3E
is in lighter ships with less batteries, indeed he claims the climb
rate of the Waco with Astro 05 fai is 2500 fpm. He claims it will
climb vertically on 10 cells with AStro 015 FAI. I would buy this
ship in a minute if I had any wing bagging experience. It was also
interesting to note the technique used by Jason Perin for flying
his 24 oz/sq ft F3E ship. These things apparently do not circle
tightly at all, Blakeslee stated that the circles were approx. 50 yards
in diameter.
Regards,
Jim
|
| 405.101 | Price of Waco 570 ? | ELMAGO::TTOMBAUGH | Go ahead...make my plane. | Wed Aug 28 1991 16:00 | 12 |
| So how much is Westons Waco 570 ? I've seen the pictures in RCSD,
and it looks similar to the Impulse that I'm going to electrify,
as soon as the faint stirrings of electro-lust swell once again
to a sufficient
level of building passion. Whoops, excuse me I meant to say I'm
d*mn tired of building and don't want to do it for awhile.
F3E planes usually don't have flaps, so it's not surprising that
you would be doing 50 yd. circles while keeping the bank angle
flat enough to thermal well, "well" be relative in this context.
Terry
|
| 405.102 | WACO 570 | USRCV1::BLUMJ | | Wed Aug 28 1991 16:49 | 11 |
| The WACO 570 is available direct from Weston Aerodesign for $195,
you bag the wing. A completely built one with your radio gear
installed is $600. The ship uses two servos installed in the tail
to run the V-tail and a servo in each wing for spoilerons. The
weight of the airframe, less radio and motor gear is 17 oz.- not
bad for a 570 sq. in. wing. The fuse is mostly Kevlar and the wing is
sheeted with kevlar and spectra.
Regards,
Jim
|
| 405.103 | RIP-Elektro Uhu | USRCV1::BLUMJ | | Fri Aug 30 1991 10:23 | 18 |
| Did something really stupid which cost me heavily. I managed to fly
my Elektro Uhu into a phone pole, which totaled the wing, distorted the
front of the plastic fuselage, and bent the shaft of my Astro 05 FAI.
It happened because I was too lazyto walk far enough out in the field
to get away from these obstructions. Depth is really distorted when
flying these planes, I had no idea I was anywhere near this pole, until
I saw it hit. Arghhh-how stupid! Anyway I am thinking about salvaging
the fuselage and making it into a T-tail with elevator and aileron
control, with the elevator servo mounted in the tail. I will build a
new set of sheeted S3021 wings about 76" wingspan 550 sq in., snd with
the room created by getting rid of the elevator and rudder servos, I
should have room for 10 cells! The Uhu was the most fun ship I have
owned to date, I will miss it and would highly recommend it to anyone
with a little flying experience.
Regards,
Jim
|
| 405.104 | Sad to see it go | CSOVAX::MILLS | | Fri Aug 30 1991 10:56 | 14 |
| That's a shame. I did the same thing with my UHU (but with a soft
tree). I had no Idea I was near a tree and wham, but no damage. It was
stuck way way up in the tree for a good while. I also damaged my Cobalt
(on another accident) and found that the bent shaft was not the biggest
problem. But the fact that the shaft gets pushed in and the commuatator
slides forward. Throwing brush alignment off. Check to see if there is
ANY play in the shaft front to rear. There should almost be nothing.
When the commutator slides forward it crushes a plastic ring between
the commutator and the winding. I managed to press the shaft out
straighten it and get it back in and it still works still today. But it has
excessive play and only friction (no plastic spacer) holds the commutator
in place. I'm sure I'll have to invest in a new ($35) armature soon.
|
| 405.105 | Oh no! Poor boy! Sad to read about your UHU, Jim! | KBOMFG::KLINGENBERG | | Fri Aug 30 1991 12:47 | 21 |
| Jim,
I am very sorry to hear about the sad end of your UHU. Hope you get across
the loss with an ARCUS and soon a FIESTA that please you.
I second that the UHU is a great plane to have fun with. I like to fly around
at about .05 errors high as well. Although it didn't bite me yet (unless this
one day when a gust hit it when it banked into final approach which made it
hit the ground with the fuselage horizontal and the wing vertical. Only the
nylon screws broke and I had to reglue part of the servo mount plate. 10
minutes later I was back in business.).
I thought of selling the UHU when the Kormoran flies since I really don't
need two planes of equal size. But I just can't part with it, it seems.
I tend to fly (thank God for the area we live in) far away from any high
reaching (and maybe even grabbing) obstacles. I hope I can keep it for
many more flights (and even some novice training, maybe).
Best regards,
Hartmut
|
| 405.106 | UHU rebuild/modifiactions | USRCV2::BLUMJ | | Wed Oct 09 1991 12:16 | 39 |
| As
As my ARCUS is nearing completion, I am starting my next electric
project - rebuilding my UHU with some modifications. I am attempting
to fit the UHU with a blue foam fin with enclosed servo to operate a
T-Tail. I am hoping to fit An ASTRO 25 GEARED FAI motor to run on 14
900 mah cells. The wing will be rebuilt to around 74" with a Selig
3021 airfoil with a servo in each wing for ailerons/spoilerons. By
getting all the servos out of the fuselage, there is plenty of room for
the 14 batteries. If this configuration flys well, I would like to
use an RG15 airfoil. Ted Davey's recent experiments with motor/prop
combinations(RCM magazine) really put a favorable light on geared
motors, more thrust with less current draw. The motor/prop combination
I am attempting to use should give a thrust to weight ratio of nearly
1:1, which should yield nearly vertical climb.
Regards,
Jim
|
| 405.107 | ASW22 B270 comments on | CSOVAX::MILLS | | Sat Oct 26 1991 22:13 | 35 |
|
I'm thinking of ordering the Graupner ASW22B B270 for $279.00
It looks like a great plane.
Wing Span: 105"
Length: 46.5"
Wing area: 679 sq in.
Airfoil: Epler 195 modified
Weigth: 79 ounces !!!!!
Functions: Rudder,Elev,Airerlon,Motor
I'm concerned about several things:
1) Wing loading around 16+ ounces/sq ft, I don't want anything
faster than my UHU at 14. But I hear bigger plans fly better.
Will it be graceful or hotter than my UHU?
2) Can I handle a plane like this with out a programable radio
(no mixers, no nothing).
3) Can I push my astro geared 05 on 8 cells and a very big prop.
(I don't mind up grading this later).
4) Hobby Lobby sells great stuff but they are usually over priced
can I get a comparable plane for less elsewhere? Does Northeast
sailplanes (name?) the place that you guys rave over the $5.00 catalog
carry eltricfied sailplanes. Maybe I should look at those first.
5) My UHU is 1/2 ARF and flew great. This is 3/4 ARF (presheeted
foam wings and ABS fuse). ARF has a repution of not being as
good as a non-ARF. Is this plane too ARF?
The reason I like is that. It's bigger than what I have. It has sheeted
foam wings (which I'm not ready to do myself yet). It has a T tail.
And graupner has a good record. It's also in my price range.
|
| 405.108 | ASW22 thoughts | USRCV2::BLUMJ | | Mon Oct 28 1991 14:44 | 36 |
| Although I have never seen the electric ASW22B, I think it might cause
some problems for the following reasons:
1) Since this ship uses plug-in wings, I think getting all the gear
in it could be a real nightmare.
2) I think that the landing this ship with out airbrakes could be
tough.
3) How about parts availability- what happens if you severely damage
a wing, do you trash a $300 glider because you can't get a wing?
4) I think the performance on a geared 05 would be disappointing.
My recommendation would be to adapt a light 100" glider for electric
flight using your geared 05. My father electrified his 112" MIRAGE
which soars very well and climbs decently on 7 cells with a geaed
Astro 05. All up weight is 54 oz.
I really don't think there is a sheeted wing glider over 2-meters
in wingspan that would climb very well on a geared 05. I have
read that a geared 05(Ted Davey's column in RCM) is capable of about
26 oz. of thrust. I would not want to exceed a total all up weight
of about 60 oz. with the geared Astro for motivation.
Terry Tombaugh called his electrification of the Graupner ASW22B
"A real character builder" due to the difficulty of getting all the
equipment to fit.
The reason I ended up buying a computer radio was so I could mount
aileron servos out in sheeted wings, thus making room for motor
batteries in the fuselage.
Regards,
Jim
|
| 405.109 | Graupner ASW22 electric memories | ELMAGO::TTOMBAUGH | Homo Erectus with car keys | Thu Oct 31 1991 10:47 | 66 |
| George asked me to comment on my experiences with this plane, so after
a 5 day vacation,I feel up to it ,maybe.
My version was the built-up wing, 99" span. Both versions use the same
fuselage, and therein lies the real work.
I built the shallow v-dihedral version without ailerons. Since the
foam wing can't/shouldn't be built with polyhedral by all means use
ailerons. Mine was hard to keep in a turn without them, without
spiraling in too steeply.
I used spoilers, they aren't really necessary unless you have a
tight landing zone. With a computer radio and servos in the wings
reflexed ailerons will accomplish the same thing.
Keep as much stuff out of the fuselage as possible, another reason
for wing mounted servos.
My installation was nightmarish because I had three servos, speed
controller, rcvr and batt. and motor batt. all trying to fit in a
smaller space than you would think. The rounded scale-like fuselage
really cuts down interior volume compared to a box fuse.
I wound up mounting the stuff in three layers, and had to reconfigure
the 7 cell motor batt. into an in-line pencil shape in order to fit
and to get a little more weight aft to avoid a nose heavy condition.
The entire electric installation had to be custom fabricated. There
was a supplemental diagram showing how to make the ply nose bulkhead
which the glider version doesn't have, other than that you were on your
own. The later foam wing kits may be different, I hope.
I don't remember what it weighed, didn't have a scale at the time.
I'd estimate 65-70 oz. Wing area was ~800 sq. in., the built up wings
were broader chord than the foam version.
Power was a Graupner Speed 600, 104 watts, swinging a Graupner paddle
blade 12.5" prop. The pitch numbers were never published for that
style of prop, earlier model before the Scimitar line came out.
The blades were so flexible that I'm sure it flattened out under load.
It was geared 3:1 with the Graupner gearbox that bolts up to the front
of all their 1 3/8" diameter motors.
The 12.5 X 6 scimitar prop would be ok with a geared Astro.
Climb performance was adequate but little margin for error on stall
warning. Directional control was a little squirrely without ailerons.
Soaring performance was good but had to be kept moving pretty fast.
Landings were exciting.
As Jim says, performance with an Astro 05, at 76 oz. is going
to be marginal.
If you must electrify it a 15 on 12 cells would be the better
minimum choice.
My opinion would be to fly it as a pure glider and electrify a lighter,
less complex plane.
I still have the wings, in perfect condition, and the remains of the
fuselage, low altitude stall, 'nuff said.
The thing I will remember most about this plane is that I lost it
behind a slight rise ~200 yards away on landing once, and it took
6 of us an hour to find it. This in an area with no trees within 3 miles,
and no bushes larger than a TV set.
Good luck.
Terry
|
| 405.110 | Solar cells | ELMAGO::TTOMBAUGH | Homo Erectus with car keys | Thu Oct 31 1991 12:17 | 24 |
| I received my order of seven solar cells from Edmund. A few
observations:
It's impossible to solder copper braid to these things using any
common soldering technology that I'm familiar with. They give new
meaning to the term "heat sink".
A friend that works for Sandia Labs says that there is a special solder
developed for this. He rattled off a polysyllable chemical
name that I don't remember. He's says he can get me a small amount.
No doubt it costs $10/inch, being associated with a DOE project. ;^(
In the meantime, testing one cell at a time with my DVM, reveals that
my two-tube flourescent shop light will produce about .15v output
no matter how close I hold the cell to the light.
My 500 watt infrared epoxy curing lamp, will peg them right out
at the max rating of .5v whenever they're held ~1 ft. away. This says
something about spectrum sensitivity, I think.
Until I can solder on some copper braid more extensive current draw
tests will have to wait.
Terry
|
| 405.111 | Tic Toc Tic Toc | CSOVAX::MILLS | | Fri Nov 01 1991 14:07 | 9 |
|
Thanks for your update on your AWS22. From what I've learned of planes
over the past year is that the wing IS the plane and if it's different
then it's a different plane.
Hobby Lobby said they can't stock them fast enough and mine was back
ordered. I guess that's good that it's popular but I sure hate waiting.
BUt anticipation is half the fun too.
|
| 405.112 | Most popular? Very interesting. | ELMAGO::TTOMBAUGH | Janine T., come fly with me! | Fri Nov 01 1991 15:20 | 14 |
| I notice in the Hobby Lobby catalog that they recommend the Speed 700
motor on 12 cells for the foam wing ASW.
This would definitely pull ~76 oz. up ok, if not spectacularly, but
a lot better than an Astro 05, and the 700 motor and prop combo is
~$50.
Also they state something to the effect that the fuselage nose has been
modified for the electric installation. This would cut down on a lot of
work, if they mean that the motor mount bulkhead is pre-installed.
Regardless of wing construction or motor type keep in mind that this
bird has a high wing loading, so be cautious near the ground and don't
expect to waft about like thistle down on a summer breeze.
Terry
|
| 405.113 | 700 is to heavy | CSOVAX::MILLS | | Fri Nov 01 1991 15:50 | 13 |
|
Problem is the 700 weighs 11.5 ouces !!!! I may go with an 05 FAI
geared 6.5 ouces (if it's just a different armeture from straight 05 I
have with a bad arm.). Else I'll probably go with an Astro 15 7.5
ounces geared/nogeared? I'd also like to stick with 8 cells if I can
for a while. 4 micro servo's,8 900 (rate at 1000) with 05 FAI geared
and 12/6+ prop and Power switch 25. I think should do it. All I'll have
to buy is Powerswitch and armeture to get me their. If I go past that
it will be a much larger investment than I had planned.
I have to call astro to find out if I can put the FAI arm. in the 05
case and how much you can push it.
|
| 405.114 | More ASW22 Thoughts | USRCV2::BLUMJ | | Fri Nov 01 1991 16:31 | 28 |
| Re: -1
From the latest RCM magazine, Ted Davey tested the geared Astro 05
on 7 cells an came up with max thrust of 26 oz. The direct 05 FAI
with 8x4 prop tested at 23 oz. of thrust. Hobby Lobby's tests with
the Speed 700 resulted in 31 oz. on 10 cells with a 10x6 prop and
46 oz. on 12 cells with a 10x6 prop(34 amp draw). After experimenting
with my UHU (Speed 600, Speed 500, Astro 05 FAI, 7x3, 8x4.5, 9x5 props)
I feel that motor thrust should be about 50% of the total weight, if
spirited climb is desired. For what its worth, Hobby Lobby's test of
the Astro 05 geared FAI with 12x5 prop yielded only 22 oz. of thrust.
Why the discrepancy between Davey's tests and Hobby Lobby's - I don't
know. I think it would be a good idea to build a test stand to see
what kind of thrust your motor prop combinations yield. I think
a motor/prop/battery combination providing 22 oz. of thrust to haul
up a 79 oz. glider would result in a very anemic climb rate, with the
pilot spending most of his time averting stalls. The test stand can
be cheaply built using a spring gauge to measure the thrust. I think
you must determine how much thrust you need, then investigate the
motor/battery/prop combinations that can deliver. If the price or
size of the equipment does not fit, then abandon the project. I have
used this criteria on several occassions and have had to give up on
a lot of my original ideas.
Regards,
Jim
|
| 405.115 | *REAL* simple(fide) math | LEDS::COHEN | What do I drive? a Taylor-Made! | Fri Nov 01 1991 16:39 | 7 |
|
Well, if you ignore drag (just to get a rough idea), a motor that
produces thrust at 50% of all-up aircraft weight ought to climb out at
30 degrees.
Randy
|
| 405.116 | Ain't no substitute for cubic money. | ELMAGO::TTOMBAUGH | Janine T., come fly with me! | Fri Nov 01 1991 17:25 | 25 |
| The weight of the Speed 700 is a stumbling block. I have one but
haven't used it because none of my present electrics can accomodate
it.
If going with an 05, I'd use a geared prop. You can haul
surprisingly heavy loads with a geared prop, but at lower speeds.
With that much plane to haul, and if your staying with 7-8 cells,
geared is the only realistic choice.
I'm under the impression that the main difference between an FAI
05 and a standard 05 is the number of armature windings.
The FAI version flows a lot of current in a short time, with less
duration. This is good for a direct drive, small prop, F3E style
climb performance, but isn't so well suited for the leisurely
climb performance of the ASW, where you would probably want
more than ~1 minute of useful power.
If all you want is to climb to hi-start/thermal altitude a few times
per charge, a climb angle of 10-15 degrees and a few minutes duration
is adequate.
Trying to get the best price/performance ratio is always a hassle.
Terry
|
| 405.117 | comments | CSOVAX::MILLS | | Fri Nov 01 1991 20:12 | 31 |
|
You have to be carefull using the Hobby Lobby tables which are very
helpful but they vary props and cells all over the place so it's very
hard to compare apples to apples. And nothing can be linearly
extrapolated reagrding this stuff.
Just a guess that ASTRO is much more conservative in what they
recommend as far as pushing a motor to the limit. I suspect they are
over stressing the turbo 700 at 10 and 12 cells with 10x6 props.
If I did use the turbo 700 for greater thrust I would have to add
2 Cells+Recv batt(no BEC over 9.6v)+5 ounces of motor+nobearings= ~10oz !!!
The turbo 700 on 8 cells, 10-6 prop has same thrust as 05 FAI on 7
cells and 7-3 prop. But the RPMs are different and they will perform
differently in the same plane.
I'd also be happy with just one good climb or 2 poor climbs for now
anyway.
I called ASTRO today and I can get the FAI arm. replaced for the same
price as the standard !!! and they said no problem. Interesting that
the dealers charge more !!!
Astro specs the 05 FAI at 7 cells but I could not talk to anyone who
could tell if 8 cells is safe. I'll bet 8 cells on an astro 05 is safer
than 10 or 12 on turbo 700.
Also regarding a note on power switch 20/25. The specs read the the
voltage ranges are different between the two not just the amps in the
relay. 6/7 cell vs 7/8 cell.
|
| 405.118 | Weston 7-570 preliminary report | ELMAGO::TTOMBAUGH | Janine T., come fly with me! | Mon Nov 04 1991 10:27 | 84 |
| re .117
I'd agree with most of that. I do think the Speed 700 will handle 10
cells just fine, it's quite a bit heftier with a bigger armature
than the 7 cell models, but like you say, switching to a bigger
cell count means replacing a lot of other equipment.
My Weston 7-570 arrived on friday. Some preliminary impressions:
This is a minimalist kit, he gives you all the stuff to build it,
a basic outline as to how to do it, a few drawings for clarification,
and then you're on your own. Anyone without prior foam wing experience,
don't even think about this kit.
My first step was to weigh everthing in the box that will be on the
finished product to see how realistic the 38 oz. ready to fly weight
is.
Total parts weight: 462 grams/16.3 oz.
This includes 25 sq. ft. of glass cloth and 20 sq. ft. of Kevlar cloth.
No doubt some of this will be excess and trimmed away.
The gray foam cores are bagged with the Kevlar against the foam and the
glass cloth on top, with the mylar sheet technique.
The bare fuselage is 47.4 grams/1.67 oz. It comes in two pieces, the
tail boom is a slip joint over the forward pod. It's laid up on a male
mold out of one layer of glass cloth and one layer of Kevlar, with a
third layer in the wing saddle area. I can't tell what the third layer
material is. The Kevlar is on the outside and gives a slightly coarse
feel to the surface. Rigidity is like holding a small diameter
lampshade. The fuselage must be finished by sanding the mating joint,
the wrap joint where the Kevlar ends when wrapped around the boom
mandrel, then a coat of clear epoxy is flowed on over the whole thing.
The gray foam stab cores are thick enough to just barely house an S-133
servo or JR-305. I'll be using the Kyosho KS-10s which are slightly
smaller and lighter.
The elevator actuation comes from a piece of shrink tubing glued onto
the suface of the bagged elevator. The pushrod is bent in an L, and
inserted in the shrink tubing. A piece of kevlar is glued over the
shrink tubing for reinforcement. Ingenious for weight saving, but
too adventuresome for me. I'll be using horns made from PCB material
and inserted into the l.e. of the elevator.
The motor mount is a ply disk, cut and beveled to fit in the nose.
The motor bolts up behind it. If using an Astro cobalt motor, the
brush holders serve as the aft locators by butting up against
the sides of the fuselage and prevent lateral motor movement. There
is no indication that any other motor retainers are needed. We'll
see.
All clevises, servo wiring, Deans plugs, pushrods, are supplied.
The wing cores are in 5 pieces, one center section, 2 on each side.
The tip pieces plug on with ~1/8" rod and tube. The inbd. and outbd.
panels both have hefty ply root ribs and a carry through rib mounted
~3 in. inbd. to carry the tube.
The wing bolts on with two steel allen head set screws. Blind nuts
in the ply wing saddle doubler.
All equipment must be inserted through the wing saddle cut out.
Wing must be removed to change batteries.
The wing has no separate l.e. The quality of the builders cloth
butt joints at the l.e. determines how well this will work.
The instructions suggest vinyl tape along the l.e. without stating
why this may be necessary. No wing spar is used. An optional 1/8"
X 3/8" is shown on the wing drawing. No clue as to whether
it's on one or both sides. I'll go sparless, since it won't
have to withstand winch launches.
Obviously this thing is designed for max performance, period.
IMHO the overall kit engineering is as far removed from the older
cottage industry kits (Sealy, Dodgson, etc.) as those kits are
removed from the mass market kits.
In summary, he gives you everything you need to do the job. If
you have the personal vision and experience to combine the ingredients
correctly you'll wind up with a plane that breaks new ground in price/
performance ratios.
Terry
|
| 405.119 | Keep us posted | USRCV2::BLUMJ | | Mon Nov 04 1991 11:08 | 16 |
| Terry,
Please keep us updated on the 7-570 as you build it. From
your previous reply, I am not sure how you feel about the kit.
Is the kit worth $200? Do you feel that a factory completed
version with your radio gear installed would be worth $595?
After talking with Frank weston he claimed the 38 oz. weight
was legitimate if 600mah batteries were used. I would love to
see this ship fly with an Astro 15 FAI on 10 600mah with a 9x5
prop. Even though motor run would be less than a minute, the
total weight of this combination would only be about 45 oz.,
which should yield several great climbs.
Regards,
Jim
|
| 405.120 | More on 570 | ELMAGO::TTOMBAUGH | Janine T., come fly with me! | Mon Nov 04 1991 11:55 | 27 |
| Well, no it's not worth $200, but the kit is $100. It's worth that
in comparison to other cottage industry kits, and especially in
comparison to what the German F3E style kits cost.
A completed version for $595 would not be worth it IMO, because you can
buy completed, proven, F3B designs for that amount.
However, if a person had money to burn, an equally burning desire to
own a 7-570, and not much building experience, and he had peeked into
a kit box and realized what was entailed in building one, I can imagine
him springing for a completed version. I think Weston can imagine this
too, and has seen the reality numerous times, which helps explain
why most of his design are available pre-built.
Basically I like the kit, I think it will turn out well. Given that
there is plenty of opportunity for irreversible screw-ups, I'll have to
take things slow.
He recommends against painting the wings, use tinting paste instead.
This didn't work well on the Ninja, in the sense that the finish is
really white. However he mentions the method of painting the inner
suface of the mylar sheet with automotive lacquer, which then transfers
to the glass surface during bagging. I'm going to try this on the
bottom of one stab half. If it works, I'll use it to make the wing
bottoms bright red and the tops white, and also use tinting paste
to hedge my bet.
Terry
|
| 405.121 | Power package for Weston 570 | ELMAGO::TTOMBAUGH | Janine T., come fly with me! | Wed Nov 06 1991 10:14 | 19 |
| After thinking about how I was going to power the 570, and comparing
price/performance ratios, I decided to spring for the complete
power package that Weston sells. His price was $8-23 cheaper than
buying all the pieces separately from H.L. or locally.
The package includes an Astro FAI 05 motor, already wired with the
new $10 Astro plugs, an 8 X 5 Freudenthaler prop, hub, and spinner,
a Robbe 50 amp on-off throttle control, a set of Astro plugs for
the throttle control, SCR 7 cell batt. pack, with Astro plugs
installed, and a prop/motor shaft adapter.
The new Astro plugs look like really quality units. Whether they're
worth 2.5 times as much as the Sermos plugs remains to be seen. The
rounded edges make them a little more compact but overall dimensions
are similar to the Sermos.
Terry
|
| 405.122 | Is it competitive in F3E? | 18199::WALTER | | Wed Nov 06 1991 12:38 | 6 |
| Terry,
Is your Weston 570 supposed to have the rocket like climb of the
F3E planes? Or would you have to substitute a bigger motor/battery?
Dave
|
| 405.123 | Hi perf. thermal version | ELMAGO::TTOMBAUGH | Janine T., come fly with me! | Wed Nov 06 1991 13:02 | 13 |
| Weston claims 2500 ft/min., measured with a Casio altimeter watch,
at 38 0z.
This isn't F3E level performance but it's darn good for a 90"
span bird on 7 cells.
His F3E version is 60", and uses an Astro 15 on 10 cells.
The 15 and 10 cells will fit into the 570 but I decided against
that because it would mean getting too much new support gear
Charger, throttle, packs, etc.
Another guy here is going to try running his Astro FAI 05 on 10 cells.
Anyone know how advisable that is?
Terry
|
| 405.124 | Weston 570 construction starts | ELMAGO::TTOMBAUGH | Janine T., come fly with me! | Mon Nov 11 1991 10:06 | 29 |
| Finally got started on the 570 over the weekend.
Got the root ribs and outbd. sub-ribs installed, the cavities cut
out for the aileron servos (s133, because I had them already, and
they were unemployed), and the fuselage boom and pod glued together.
Following the directions (using the word very loosely), I was able
to get one outboard panel aligned at the proper dihedral, 2 degrees,
and the tube and rod installed, in ~3-4 hours.
Abandoning the instuctions, and using my own eyeball technique,
I was able to do the other side in 30 minutes, and it fits better.
There is just barely room for the S133s between the outbd. panel
sub-rib and the outbd. panel root. They are thin enough to fit entirely
within the foam but it's thin on the top, no problem after sheeting
with Kevlar.
Waiting to cut the stab servo cavities until I get the KS-10 servos.
The Mylar for bagging the stabs has been cut and painted with
automotive lacquer, red bottom, white top.
I could bag the wings now, but will hold off until I do the stabs to
see how well the paint transfer method works.
After realizing that I'll need to cut 10 pieces of Kevlar to bag this
thing, I ordered some Kevlar shears from ASC. No way am I going to
suffer through another Kevlar cutting ordeal without the proper
tools.
Terry
|
| 405.125 | Using extra cells | USRCV2::BLUMJ | | Tue Nov 12 1991 08:56 | 14 |
| Regarding running an Astro 05 on 10 cells, I don't know how bad this
is for the motor, but it most likely will shorten its life. Keller
says in their literature that additional cells can be used for
"competitive applications". Obviously current and the corresponding
heat will be greater. But maybe if the motor is only run for short
periods it will last a reasonably long time. I've heard the electric
car guys fast charge at 8 amps, which must shorten the life of the
nicads, but they are attempting to win at any cost. For fun flying
I probably would just spend the $100 and get the FAI 15 which was
designed for 10 cells.
Regards,
Jim
|
| 405.126 | Motor dyno under construction. | ELMAGO::TTOMBAUGH | Janine T., come fly with me! | Tue Nov 12 1991 13:14 | 20 |
| Sounds reasonable to me. I don't plan on using 10 cells on my 05, but
I'll keep track of what happens to the guy that does.
Last night I got about 50% done on a motor dyno that I'm building
to measure the thrust on several prop/motor combos. that I have.
I want to know what an FAI 05 will pull with a Freudenthaler 8 X 5,
7 X 6, and Graupner 7 X 3, 8 X 4.5. Also, what the Graupner 500 & 600
ferrite will do with the same props, and what different batteries will
do.
The dyno is just a ply tray large enough to hold the motor and batt.
mounted on two fiberglass tubes which slide on two ~30" dowels
mounted on a 1 X 8 X 30 base, high enough for prop clearance.
A door spring is attached to the rear of the sliding tray, and a linear
scale will be marked on the base, calibrated by hanging lead sinkers
from the front of the tray. 5-35 oz. is the thrust range I'll be
interested in.
Terry
|
| 405.127 | Advancing on several fronts. | ELMAGO::TTOMBAUGH | Janine T., come fly with me! | Wed Nov 13 1991 14:56 | 34 |
| The 570 project is proceeding slowly as I await the Kevlar shears and
KS-10 servos.
Last night I went ahead and cut the servo cavities in the stabs, using
S-133s as templates since they are within ~1 mm of the same dim. as
the KS-10, but heavier.
One mod. was to mark the elev. chord at 1.25 in. rather than 1.5 in.
as shown on the "plan". This will rationalize the routing of the
servo wires. If taken literally, the planform shows routing the wires
into the elevators and back out, before entering the aft end of the
fuselage boom. This is obvious nonsense, but there is no alternative
except to allow them to hang in the breeze. However the freed up .25
in. from the narrower elev. allows the servo wires to be routed
directly from the stab root into the fuselage.
Ordinarily, with a V-tail I'd want all the elev. area I could get, but
with ailerons I think yaw and roll control will be okay. For those
without mixing radios there is a rudderless version.
Tonight I hog out the inner cutout on the 3/16" ply wing saddle
so that the Astro 05 will actually fit through it, since that's the
only way to get the motor in the fuselage, glue in the nose ply
bulkhead motor mount, and maybe drill and mount the wing hold-down
blind nuts. The fuse. can't be painted with clear epoxy until the
stabs are bagged and mounted.
The motor dyno project began to take on a life of its own. I knew
it was time to rethink part of it when I started envisioning
articulated paralellogram legs that pivoted up like some sort
of 155mm gun carriage.
However the motor clamp and mounting tray was given its trial run.
With a partially charged 900 SCR pack and a 8 X 5 Freudenthaler prop
the old 05 FAI cleaned off one entire end of the work bench in record
time and sent the cat looking for more peaceful climes.
Terry
|
| 405.128 | ARCUS finally done | USRCV1::BLUMJ | | Mon Dec 02 1991 16:41 | 10 |
| Well my ROBBE ARCUS is finally done. All that is left to do is
program the radio and install the RCD micro 5-channel receiver I
have coming. This thing sure seems to weigh alot, I do not have
a scale, but it must be around 4 lbs. Sure hope the Astro 015
FAI will be able to pull it up. I'll post the results of the
first flight when it happens, along with the weight.
Regards,
Jim
|
| 405.129 | Flite Line Electrics | USRCV2::BLUMJ | | Mon Dec 09 1991 08:40 | 16 |
| I received a call from Ed Slegers(columnist for RCSD) on Saturday. I
had written him a letter earlier asking among other things about
electrifying the Swift 400. He tells me the Swift 400 is no longer
available, as Mark Allen did not feel the slope market is large enough
to support this style ship. He did inform me that within the next
month Mark will be anouncing a new line of electric gliders, both
thermal and sport models. The fuselages will be wide enough to
accomodate everything and he told me the sport model will use the
SD8000 airfoil with a span of about 70". These ships are designed
to fly on 7-10 cells(obviously this is the largest market for
electrics). Ed was really high on these new Mark Allen offerings,
I will be anxious to see these models.
Regards,
Jim
|
| 405.130 | servo in fin construction | USRCV2::BLUMJ | | Mon Dec 16 1991 13:14 | 16 |
| I finally got the servo in the fin arrangement done for my poor man's
f3e project - a modified Graupner UHU. I did this by cutting the fin
planform out of 1" blue foam and gluing a 1/8" ply template on the top,
bottom and trailing edge of the fin. The excess foam is simply sanded
till the block touches the templates. The entire fin was then covered
with 3 oz. glass and epoxy. The servo cavity was then cutout and a
Futaba S-33 fitted. The stab is bolted to the top of the fin using
blind nuts and nylon screws. The elevator is connected to the servo
via a 1/16" metal rod. The battery compartment now will have room for
as many as 14 900mah cells. I will be constructing a new wing of
approx. 70"-74" span for this project. I would like to use the Turbo
speed 700 on 12 cells if it will fit.
Regards,
Jim
|
| 405.131 | Astro motors | NICCTR::MILLS | | Mon Dec 16 1991 14:01 | 13 |
| I spoke with ASTRO flight again and got some more details on motors.
The 05 FAI is different than the 05 independent of the armature. The
brush holders are different and the magnets also. But he said the
armature is comaptible with both. So if you put and FAI armature in
the 05 case you will get 95% of an 05 FAI.
I also asked him how far you can push the 05 FAI. More than 7 cells?
He said yes. You can do what ever you want as long as you do not exceed
35 amps.
I also asked him how well a 15 would run on 8 cells and he said
the "15 doesn't" sing until 10 cells". I ordered the 15 for my ASW.
|
| 405.135 | More Weston trivia | ELMAGO::TTOMBAUGH | Janine T., come fly with me! | Mon Dec 16 1991 15:56 | 38 |
| The various systems status of the Weston 570 are:
Wing and ruddervators: balsa l.e. edges installed. Airfoil integrity
much better now.
Still awaiting the two Kyosho KS-10 servos for mounting in the stabs.
Availabilty date pushed back to Dec. 30.
Got a Jomar SM-4 speed controller, 18 cell capacity. This is one fine
unit. It's only ~3\16" thick ! All surface mount components, and
packaged in a see-through blue plastic case. 2500 hz. frame rate which
will allow me to operate at partial throttle without the "bucket of
bolts" effect prevalent with my old 50 hz. Novak.
The Astro 05 FIA motor, to be used in this project came with the new
Astro $10 connectors, ditto a new Astro batt. pack.
Since all my other packs/charger have Sermos connectors, compatibility
would have been an expensive pain to achieve. My solution was to make
up one Astro-to-Sermos adapter. This can be used to charge the pack
with the Astro conn. and can also be used to adapt my Sermos packs
to the FIA motor. Of course this will mean an extra set of plug
contacts between the motor and batt. but the extra resistance shouldn't
be noticeable. It's not like I'm making a living from this stuff, after
all. ;^)
The wing mount scheme was switched from two 6-20 steel bolts to two
10-20 nylon bolts, giving me a fighting chance to minimize crash
damage, euphemistically called 'catching a wing tip on landing'.
The fuselage needs painting, after a prelim. equip. installation.
A 30 amp fuse and safety switch needs to be installed on one side
of the batt.
Horns and pushrods to be installed on all surfaces, and hinged (tape)
Terry
|
| 405.136 | Poor man's F3E lives | UNYEM::BLUMJ | | Thu Mar 26 1992 08:45 | 10 |
| My long drawn out "poor man's f3e" project is still alive. Impressed
with the wings which came with my ROBBE ARCUS, I was able to order
an additional set for $80. Expensive, but they are presheeted with
obechi and are nice and thin - just what I needed. My first motor
will be the Speed 700 Turbo on 12 cells. This is a nice inexpensive
motor in case this "experimental" design crashes.
Regards,
Jim
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| 405.137 | More WACO 10-550 thoughts | UNYEM::BLUMJ | | Fri Aug 28 1992 12:45 | 18 |
| Since I have talked much about Weston Aerodesign ships(particularly)
the WACO 10-550, I would like to make some additional comments
about the 10-550, now that I have had time to look it over and
trial fit some equipment.
The 10-550 is a serious 10 cell F3E design. The equipment will just
barely will fit, with no room to spare. The wing must be removed
each time you need to charge the battery. This is common fare for
f3e ships, but can be kind of a bother for the sport flyer.
Designs withmore room in the fuselage and a canopy make equipment
installation and charging easier.
Regards,
Jim
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