T.R | Title | User | Personal Name | Date | Lines |
---|
1557.1 | Pushrods | LEDS::WATT | | Wed Sep 15 1993 08:49 | 11 |
| Dave,
I'd go with pushrods. Cut a hole in the bottom of the fuse if you
have to. Noone will notice a patch there. Also be careful to get the
ailerons slop free. I have seen aileron flutter problems with this
plane. The standard hinging is a mess. Make sure that they won't pull
out. If they are marginal, rehinge the control surfaces. Also seal
the hinge gaps. I'd go with servos in the wings instead of belcranks.
The plane flies great if you get the controls solid.
Charlie
|
1557.2 | How about pull-pull? | GAUSS::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Wed Sep 15 1993 09:34 | 4 |
| For the fuselage, consider putting holes on both sides and running
pull-pull controls. Just mirror the horn on the opposite side and
hook up the wires. You can use a piece of nyrod to snake the wires
through initially and then remove it and connect them up.
|
1557.3 | Hard on Servos | LEDS::WATT | | Wed Sep 15 1993 10:08 | 6 |
| I wouldn't go pull-pull unless you have ball bearing servos. The load
on the output shaft will wear it out. Pull-pull is good if you do it
right but so are pushrods.
charlie
|
1557.4 | | GAUSS::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Wed Sep 15 1993 10:23 | 8 |
| I was thinking more from an ease of installation point of view but
yes, BB servos are strongly recommended. The BB conversion kits offer
a reasonable upgrade (Tower has 4 Universals for about $17 which fit
the $15 JR 507s)
The problem I usually have with pushrods is getting them into the
fuselage and out the holes on the already built planes. I guess a
Telemaster might have a bit more headroom 8^)
|
1557.5 | Tube Trick | LEDS::WATT | | Wed Sep 15 1993 10:28 | 7 |
| The tubing trick will work on pushrods. You run a piece of nyrod
through the fuse and slip it over the pushrod end. Then pull it back
through and feed in the pushrod. Works even with Y pushrods for dual
elevators. Many ARF's come with the tubing just for this purpose.
Charlie
|
1557.6 | Pull-pull setup | BAHTAT::EATON_N | Stupid English Ker-nigg-it | Wed Sep 15 1993 11:33 | 23 |
|
If you go pull-pull then you can use a system where you connect the
wires to a swivelling arm, then connect the arm to the servo, you then
have no side strain on the servo. So :
wire to horn
-------------------------I
I------I
Swivel --> O O <--- servo output arm
I
-------------------------I <- swivelling arm
I'll never be good at ASCII graphics (sigh)
In the UK Flair make a really neat moulded gizmo to do this, which
incorporates a spring loading to keep the whole thing nice and tight.
It also lets you get away with sloppy horn geometry. Neat product!
Cheers
Nigel
|
1557.7 | pushrods sound good | CSC32::HAGERTY | Veni, Vedi, $Cmkrnli, Rebooti | Wed Sep 15 1993 11:39 | 16 |
| From what everybody's saying, it looks like pushrods are the way to go,
as I'm not keen on cutting into the model if I can help it. The fuse
is slab-sided with no opening between the bays, so I'd probably end up
with quite a mess.
Since pushrods are it, I guess my next task is to figure out how to
make pushrods work without scraping. The exit holes for the elevator
and rudder are almost directly below the front of the horiz stab and
there isn't much space to work in there. I tried using dowel rods, but
they ended up banging together and scraping. What would be *IDEAL*
would be something that is a) rigid b) small in diameter and c) has a
2-56 rod on the end. While I'm at it, I'll wish for world peace.
How can you make pushrods work in such a small space?
Thanks for the help.
|
1557.8 | Small and Stiff.. | SHIPS::HORNBY_T | Soarers are rarely Silent | Wed Sep 15 1993 12:48 | 9 |
| If you're going for push rods in a tight space then Glass or Carbon
arrow shafts or kite sticks are worth a try the 3/16" (4-5mm) diameter
are very stiff.
Personally, I'd go for the closed loop (on Rudder at least) with the
servo saver as described by Nigel ..(-.2 I think).
...But then a Glider Guider would ..they do it all the time..
Regards Trev
|
1557.9 | Arrow Shafts work Well | LEDS::WATT | | Wed Sep 15 1993 14:48 | 11 |
| Dave Brown makes nice pushrod kits that come with Plastic ends. He
makes both fiberglass and carbon fiber shafts. They are about 1/4 inch
in diameter. I hate the extra linkage in the pull-pull with a
belcrank. I go directly to the servo but I use double ball bearing
servos to do the job. My Conquest rudder has ZERO slop. I used Kevlar
string for the pull-pull and it's very rigid and friction free. You
don't need to string it that tight if you have a material that doesn't
stretch like Kevlar.
Charlie
|
1557.10 | Use stiff snakes!. | CSTEAM::HENDERSON | Competition is Fun: Dtn 297-6180, MRO4 | Wed Sep 15 1993 15:09 | 9 |
| In a tight installation I would use a full length 256 rod and sleeve.
Dubro sells them already packaged.
To make an exit hole I use a chainsaw file. It is about 3/16" in
diameter and is a constant thickness. It is about 12" long and this
allows you to file a groove that will line up the cable/rod with the
horn and servo.
E.
|
1557.11 | Replace yellow with black | GAUSS::REITH | Jim 3D::Reith MLO1-2/c37 223-2021 | Wed Sep 15 1993 15:31 | 2 |
| Sullivan makes a set now with carbon fiber inners that aren't temperature
sensitive.
|
1557.12 | AMAZING..... | ELMAGO::RMOUSER | RON MOUSER, ABO/B3,552-2152 | Wed Sep 15 1993 18:00 | 5 |
| As Eric said in .10 I heartily recommend solid 2-56 rods. Using the
chain saw file is EXACTLY how I do it. Doing it this way eliminates
ALL quesswork later. Once trimmed, always trimmed.
Ron
|