Just done my preliminary balance with OS 91 FX and the rudder servo needs to go in fuse by the wing as I set it at the rear position it was way to tail heavy will how ever have to add 3/8 oz. on rudder about 2 in. back from hinge line, I could and may put the servo on the bottom of the fuse at a place where it balances perfect still using a pull-pull method, I have done this on other planes to get the balance right and works great, but then may still use the aft location and move some things up front would probably work also, weight as of now is 8lb 13 oz.