Moving wing to change cg
 

I have a tail heavy spad coro plane and have had to add 2 plus lbs of weight to it.
I have added 2.95 lbs to nose and want to eliminate the uneeded weight.

Move wing forward or back ?

RE: Moving wing to change cg
 

Back.So it Balances when hung obout 1/3 back from leading edge.That will definetly get you close!!

RE: Moving wing to change cg
 

If you're adding 3 lbs to the nose of a SPAD to get it to balance then you've got other issues at play here. Could you post a picture of what you've built and some measurements so we can see what is the real issue?

RE: Moving wing to change cg
 

I'll take a picture from the side of it and post it.
I did add some thin ply wood in the back to make the
fuselage a little sturdier, but the wood really was not thick.
The motor weighs 2.43 lbs.

RE: Moving wing to change cg
 

This is not a simple problem.

The relocation of the wing along the fuselage induces a relocation of the center of lift.

Because the wing has its own weight, the cg gets relocated as well.

As the CG moves aft, the tail moment gets reduced (tail becomes less effective).

RE: Moving wing to change cg
 

Hi JoelStolarski
I had the same problem with my SPAD Profile Biplane. I made a mistake with the CG and was forced to move both wings back to get the correct CG without adding a lot of weight to the nose. Plane flew perfect for about 5 years.

RE: Moving wing to change cg
 

That's a neat biplane Villa.

Anyhow, i'll leave the wing alone, did some thinking about
moving the wing and it'll make more sense to plan on using standoffs.

I'm going with using standoffs for the engine, because
I was lucky to find some nylon round stock to make the standoffs with.
I'll get the measurement with some all thread and then drill the nylon stock
so the allthread will have something around it to strengthen it.

RE: Moving wing to change cg
 

Istead of 4 separate standoffs even with sleeves you may want to look at doing a single plywood spacer box to fit over the lengthed mounting studs. A box will provide more rigidity than 4 separate standoffs and would look better to boot.

RE: Moving wing to change cg
 

Yes still cg problem even with engine with spacers.
Frustrating !!!!!!!!!!!