Matt,

These are interesting points.

I think the MK bellcrank became popular because it allowed classic pattern ships to use one servo and accomplish essentially the same thing that dual elevator servos in the fuse rear or in the stab do. On the other hand, DEPS seems like an alternative when building a wood fuse but not so tangible with classic glass fuses.

Tim seems to think that the tail post arrow shaft positional locking causes elevator differential. It seems to me that the only way that this can occur is if the steel elevator rods themselves flex, or, if the positional locking of the shaft causes the elevators to bow it upon heavy loads. I know that a great number of forked arrow shaft pushrods are merely supported by the servo in the fuse. In time, people like Dick Hanson, started to show a support system for the servo end pushrod length to avoid the servo from carrying the weight of the pushrod at that end.

While heavy, perhaps the use of the tail post bearing in combination with either 4-40 elevator rods or fuse exit supported 2-56 rods might accomplish the best zero slop setup for classic glass fuses.

Any thoughts?

David.

P.S. Tim, what is your thinking behind your comments.