What I have done to eliminate that problem is to use pull-pull on ele. and use a 4-40 rod on rudder (with keepers in two+ places). Put your ele pull-pull horns on one side of the ele. and put the control horn for the rudder on the opposite side of where you put the ele horns. (that way, the horns miss each other) Also make sure that the rudder horn is put on as low as possible.

This is what worked for me so I hope it helps you!

Craig Rideout