Hi All,

Bought a glow plane today, graupner trainer with servo and 61 motor all for just 15 dollars!!

Now I have gotten the damn thing home I cannot work out the best way to fit the motor. I have been to hobby lobby and looked at the different types of motor mounts but have no idea which one I need! Can anyone make any suggestions please?!?

Also, how do I couple one of the servos to the front wheel for steering as I see it has that facility built in.

I have attached some fotos (i hope) so you can see the setup at the front.

Thanks in advance
Englischdude

it looks from the pictures that your motor moun is built in. You should just drill the holes and mount the engine(if it does not fi the holes provided). Second you attach the front wheel to the rudder servo usually by placing the control arm in the servo horn on the opposite side from the rudder. meksure everthing pulls in corect direction.

Mount the motor on two aluminum strips about 1/8th inch by 1/2 inch by whatever length fits. Bolt the strips to the plane and the motor to the strips.

One look at a nose gear steering rig in someone's plane will tell you more than a bunch of words. But it's a flexible cable inside a plastic tube, with small connectors on the servo wheel and the nose gear steering arm.

OK, but do I need to mount any vibration absorbing material in between the motor and mount, or mount and wood??

No, not necessary, just make sure it is tightly bolted.

You don't need soft material between the airframe and engine. HOWEVER... use allen screws with locking nuts to fasten it. Buy the allen wrench set and the socket set, you'll use them. If you don't know what allen screws or locknuts are, ask your haardware man.

Good luck,
Dave Olson

I hope this will give you an idea as this is my setup.The front of the plane is to the left, top left servo is for throttle,top right is for elevator,bottom right is for rudder and front wheel.Hope this helps.

englishdude,

That is an old style mount. Haven't seen one like that in years.

It is designed to be larger than the engine. You need to make a plywood plate (3/16" to 1/4" thick) that will bolt on to what's already there.

The idea is that (In case of an accident) the plate you make is supposed to break thereby saving the rest of the plane

OK.

Thanks for the tips, one more thing, I bought this plane from a guy who was obviously sick of the sight of it (good for me)

How do I know what the centre of gravity should be when I am finished assembling? Needless to say instructions where not included with my bargain package!

Thanx
Englischdude

I would cut the other, unusued arms off your elevator servo. It's a slim chance that it and the rudder servo will bind, but better safe thanb sorry. Otherwise setup looks good.

Center of Gravity on a trainer should be 33% of the chord of the wing. In other words, measure from front to back on teh wing, right next to the fuselage. Divide that by 1/3, and the CG should fall that far back from the leading edge of the wing. It's USUALLY right on the main spar......

Andy

It should balance about at the spar, where the wing meets the fuse (or about 25% back from the leading edge). Balance on your fingertips, with them under the wing.
Dennis-

One more thing to add...

Make sure you get proper instruction. If you haven't flown before, expect your first flight to last about 15 seconds.

Hi Mike,

Ive been flying electrics now for some time, but being an engineer I have been looking out for a bargain to keep my greasy hands satisfied, and something which is not quit so user friendly so that I always have something to do when the wife has the girls round........ tupperware just aint my thing )

Thanks
Englischdude

A65l, I disagree. If one devides any number by 1/3 it is the same as mutipling by 3! To devide "invert and multiply". However your first statement is correct that more or less 1/3 of the cord is a good place to start if the main spar of the wing is at or about 1/3 of the weight and ballance, fore to aft. On "most" model airframes the center of gravity (main spar location" will be the same.

I hope this helps and please excuse the spelling but I am from TEXAS.

fly the airplane first

73 Lee K5MRC

The balance on My Hobbico Superstar Arf with Super Tigre .51 is 3 Inches <dry> and it's flight characteristics are great.... Its right where the Leading edge sheeting stops.... Hope this helps.



If you balance it with a half tank of gas its best

I strongly disagree with this. ALWAYS balance a plane with an empty tank. (unless the tank is behind the CG.)
Dennis-