I had an elevator servo binding issue at both extremes (even with adjusted endpoints) and when returning to centre from both directions.



Last night I diagnosed the problem. Here's reference photo; below are the steps I took, checking after each to see if the problem was solved:

• Disconnect linkage from elevator control horns. Nope.
• Remove tubing from first to second bulkhead, leaving tubing flush with front of second bulkhead. Nope.
• Remove tubing from second to third bulkhead, leaving tubing flush with rear of second bulkhead. Nope.
• Remove tubing from third bulkhead, through fourth and to the exits. Nope.
• Enlarge holes in third bulkhead. Nope.
• Enlarge holes in fourth bulkhead. Nope.
• De-solder pushrod joint and try with main pushrod only. Yep.

I'm guessing that the path I chose for the pushrods wasn't straight enough and the friction of the bends caused the servo to bind. Joining pushrods to a single elevator servo is a common enough approach so I should be able to make it work without a second servo.

So now I'm faced with some choices...
Join the pushrods further back in the fuse to eliminate friction? Option 1.
Re-think the path of the pushrods? Option 2.


Your thoughts?