davidchoate wrote:It didnt fly so well, but the weight on the nose fell off so it was tail heavy. It would climb almost straight up and do a loop then hit the ground. Luckily no damage. I'm thinkin its the perfect weight for a little 8mm brushed motor.
That's not surprising, and part of the reason I believe these models are actually better suited to electric FF or R/C, unless really lightened, especially aft of the CG. The little Robin I built has Microlite covering, which isn't much heavier than lightly doped colored tissue. The servos are all centered on the CG, so they are a non issue in affecting the CG. With a 10gm electric motor, 2s-200 lipo, and ESC all reasonably forward of the CG, I still needed 2gms of lead to properly set the CG. With the CG just 1mm rearward of that, before adding the 2gms of lead, it still wasn't quite right. It probably would have done the same thing your model did, if I didn't have remote control of the elevator. Built for rubber I could have put all the ballast in the forward most point inside the cowl for maximum efficiency, but I still would have probably needed something like a whopping 25gms of lead, to have the same effect as the R/C gear mounted forward of the CG. That's a lot of lead!