I also use a piece of foam block (similar to the ones in the JR & Futaba aluminum case) in the middle also. Just run a hot piano wire slightly smaller than the pushrod diameter. Attach the bellcrank side first. Then, insert the foam from servo side. I used another long carbon rod to push it in. The foam is slightly wider than the location where it goes, so the fuse sides are pressing the foam a little. It never moved for the last two years.