| Title: | Welcome To The Radio Control Conference |
| Notice: | dir's in 11, who's who in 4, sales in 6, auctions 19 |
| Moderator: | VMSSG::FRIEDRICHS |
| Created: | Tue Jan 13 1987 |
| Last Modified: | Thu Jun 05 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 1706 |
| Total number of notes: | 27193 |
Hi, I am a flyer who is serious about speed and climb rate on my electric gliders. I have couple of ASTRO cobalt motors but still am very interested in every high power motors in the world. I just received Hobby Lobby #21 catalog and found their new line up MEGA series. I think somebody had replied in some topic before but I can't find it. For the first thing I was very impressed at the cost/performance ratio. For the second thing I thought that could a *Real* F3E type motor. I liked to know if it's better than ASTRO cobalt FAI motors. Anyway Let's have a look at the list (p44) and the maximum output chart in the catalog. (p45) !+ HLKM03 MEGA R3 motor 7-10 cells $219 HLKM04 MEGA R4 motor 7-14 cells $219 HLKM05 MEGA R5 motor 10-16 cells $219 HLKM07 MEGA R7 motor 12-20 cells $219 HLKM09 MEGA R9 motor 14-24 cells $219 HLKM11 MEGA R11 motor 16-24 cells $219 Made in Czechoslovakia by Karei Matyas, an engineer who has extraordinary design and manufacturing abilities. MEGA motors have been discovered by top notch German and Austrian electric flyers. Our test results put these in the ULTRA and Hecktoplett class. MEGA motors have huge neodym magnets, extra lightweight armature laminations, dynamically balanced armatures, built in electric noise suppression, and adjustable timing. They are easy to service. The "R" numbers refer to the number of armature winds. See "Max. Output" chart for outputs and dimensions. !- Every motor has the same dimensions except motor diameter and weight. Motor diameter for R3,R4,R5 is 1-5/8 and R7,R9,R11 have 1-3/16 Weight is about 14.5 oz. !+ Maximum Output chart. Stock # Max Test Free RPM Prop Amps Thrust output Volts RPM at Max size at (oz) (W) (V) at V load at max Max at Max HLKM003 239 8.4 13050 7000 12.5x5 53 40 HLKM004 351 12.0 15024 8000 12.5x6 55 54 HLKM005 495 19.2 18029 9300 12.0x6 50 76 HLKM007 548 24.0 16392 9600 12.0x6 39 77 HLKM009 635 28.8 15322 8900 12.5x6 38 87 HLKM011 557 28.8 13190 7000 14.0x7 37 89 !- I know this chart is based on suggestions and technical advice from Carl Schwab... SO I must think about the estimated maximum power. Look at the "Amps at Max" ,it is a big difference between R4 and R11. One is 55Amps and the another is 37Amps. From my experience, if this is for competition like F3E the Amps for R11 motor can be more high. Some of you might know that ASTRO 60FAI can handle up to 80A for short and 55A for constant. If I assume that the R11 is something like that , the Voltage should be 28x1.2= 33.6 Volts and Current can be 55 amp. Multiplying these two values becomes 1748 watts of input power. This sounds reasonable, doesn't it? That is my way to *very* roughly expect the inout power. But I have a questions. Does the R11 motor have the same gauge of wire as R4 motor? In other words, Do they have sufficient wire for high current? If the answer is yes, my calculation does not differ so far. BUT remember the motor diameter, small winds have more bigger diameter than motors of big winds number. Adding to that fact, R5 motor still has 50 amps at max but same size as R11. I think you can understand what I mean from the chart. Then I needed a information and called Hobby lobby. After a few minutes talking with the man who was the tester for this maximum output chart, I was recommended not to draw such high current for these motors. He didn't know about wire gauge. He said it is well compared to ASTRO 40 sized motor.(40 or 40FAI) I knew that even R9 or R11 motor are not suitable for high current like 60A. I guess these motors shouldn't be used with above 40 amps. It is natural that they are below ASTRO 60FAI because of less Diameter, less brushes, and probably less pole. Compared with ASTRO, MEGA motors are still attractive and powerful. Using 24 cells with R7 motor would be nice. That combination might go over ASTRO 40FAI because of its low rpm torqe. Sales talk says that MEGA is ULTRA or HECKT class. There is no data about ASTRO 40FAI on the chart. /Katsuya Hasegawa
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 1514.1 | MEGA information | MISFIT::BLUM | Mon Apr 12 1993 09:50 | 46 | |
Katsuya,
I have just recently purchased a MEGA R7 motor from Modellhaus
in England. Price was 124.95 lbs plus shipping. Even with the cost
of an international money order($15) it was about $10 cheaper than
Hobby Lobby. Modellhaus also stocks collets, replacement brushes,
and a nice selection of carbon fiber props(better than Graupner and
Freudenthaler) which can be sent with the motor.
The R7 on 24 cells is the motor to use for F3E work. The motor must
be retimed for 60 amp draw(this is simple to do), as it comes from the
factory set for about 40 amp draw.
This motor was actually used in last year's F3E World Championship by
a couple of Eastern Bloc competitors. The performance on 24 cells was
impressive enough to warrant comment in several international
publications(Silent Flight and Aufwind).
Objectively speaking, the MEGA is not quite as powerful as the big
Hectoplatts, Kellers(Robbe), or the modified Astro 60. It is
however, less than 1/2 the price of the Hectoplatt or the Keller.
It should be known that the Astro motors used by the USA F3E teams
are far from stock, they have special armatures, brushes and have
been significantly lightened.
At 395 grams, the MEGA really shines compared to the other competitive
motors which tend to weigh around 23 oz.
My R7 will go into a Pekris Trabi fuselage with a 2 meter RG15 wing
on 24 1000 mah cells. Flying weight is estimated at 82 oz. Vertical
should be impressive, in fact close to world class!
If the highest possible performance(without regard to cost) is what you
desire, buy a Hectoplatt. The MEGA R7 should be a very acceptable
"poor man's" Hectoplatt.
The stock Astro 60 FAI is an impressive brute at a reasonable
price(<$200). There are rumblings about a new 5 turn FAI series of
motors from Astro. I am anxiously awaiting their arrival.
For more information read notes 386 and 387.
Regards,
Jim
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| 1514.2 | What are you flying? | MISFIT::BLUM | Mon Apr 12 1993 15:58 | 10 | |
Katsuya,
I am curious what ships you are flying/intending to fly
with these motors?
Thanks,
Jim
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| 1514.3 | It's my original | DECWET::HASEGAWA | NT Support/Virtual CSC DECwest | Mon Apr 12 1993 22:56 | 38 |
Jim Thank you very much for usefull informations. I have two sailplane. One of these is being constructed. The first one is modified KYOSHO STRUTUS 2000 which has ASTRO 05 Geard with 14cells. It makes 11.5x6 Aeronaut prop turning 8400 rpm. From the maximum output chart of hobby lobby, I think the thrust is more than 70oz. Even with the difference between my aeronaut prop and grapner prop which is used by testing max power at Hobby Lobby, I think mine has that big thrust. Of cource the motor itself was modified to handle the heat from 560 watts input. Total weight is about 1600 gram(57 oz?). It performs real vertical climb like a rocket but I don't know how to measure the climb rate. The next one which I am considering to use new motor is my original. I made original form wing similar to s3021 airfoil but more thin. I will make glass fiber fuselage to adopt ASTRO 40FAI or other. I have some motors and evaluating their power. They are , ASTRO 25 Direct , ASTRO 25 Geared, 40 Gered, 40FAI, and Special 05 (my original), 05FAI, 15FAI. Before I bought these astro motors, I tested many 05 sized high pofor- mance motors made in japan. Some of those were nice with gear units but I needed more power. I wish to know couple of things about your motor if it's not secret. With what prop what rpm does your motor get ? It's very nice to know the prop make,rpm,volt,amps,cells and duration at max power before it gets very hot. Thank you Katsuya | |||||