CG
 

I need some help PLEASE, I have a Lazy Tiger, The directions say the CG should be 4 to 4 1/4 in from the LE, but the main spar is about 4 1/2 in from the LE. I was tought you always set your CG at the main spar. What is right?:eek:

RE: CG
 

Go with the directions. The CG usually falls somewhere near the main spar, but not always on it.

RE: CG
 

Well Goplaneman,you was taught wrong.:D

RE: CG
 

Ditto, the main spar is typically located at the thickest part of the wing, which is typically close to where most models balance. But the balance point (BP) really has nothing to do with the main spar. Instead, the balance "range" is determined by the airfoil shape, wing shape, loation and size of the horizontal stabs, etc. The balance point will vary from plane to plane, depending upon design. A typically BP will fall in the 25%-40% mean aerodynamic chord range. This as you can see is quite a broad range, so never assume. Always go with the plans.

RE: CG
 

Always fail safe and use the forwardmose CG for test flight. You can move it back later if performance indicats its needed. Its kinda hard to move it forward, in flight, when the plane proves uncntrollable.

Possibly... the listed CG is the test flight location and once trimmed... you may be wanting it moved back onto the spar. (or even further back...)

RE: CG
 

Thanks for the HELP, will follow the plans[sm=sunsmiley.gif]