ORIGINAL: Popriv
midwest Aerostar, 53" wingspan, .36 TT Pro engine, 4 channels, Spectrum DX6i TX.
I started this plane 20 years ago. I'm finally going to finish it.
I lost the instructions years ago.
Without the instructions I'm not sure of two things...
1. How far back from the lead edge of the wing is the CG and how much room for error?
I know tail heavy is bad!
If you have a yardstick and the model, there is a 100% reliable way to find where the CG range is for that model.
http://www.geistware.com/rcmodeling/cg_super_calc.htm
9 measurements and that's it. Plug them into the application. Put a value of 5 for the Desired Static Margin and click the bar. Readout the CG location down where it says: Ideal CG aft of root LE =
Then do the Static Margin for 15%. You're now good to go for your CG range.
2. How much movement do I need on the controls?
the info I have so far is
Elevator = 1/4" inch up and down.
Rudder = 1/4" right and left.
Ailerons = 1/2" up 1/4" down
(doesnt seem like much movement to me?)
What about the front wheel? how much movement here?
I'm having a little trouble with binding on the front wheel control line.
On grass, is the turning done with the rudder or the wheel or both?
Getting close, should finish up this week? 1st flight next weekend???
Thanks for everyones help
Pop
Very often the rudder servo is rigged to work the rudder with a pushrod that goes aft and to work the nosewheel with a pushrod that goes forward. You often use a servo wheel or star to attach the two pushrods. It's kewl because you can adjust your rudder throw by moving it's pushrod connection in or out, and adjust the nosewheel the same way. If you look closely at the servo on the left in the picture, you see the rudder connection is as far out as it can go. The nosewheel pushrod is connected to a hole closer in on it's arm. The nosewheel turns less. It's easier to steer that way.