While at the Antique Fly-in (Blakesburg) I spoke with a fellow who had flown a Fly Baby a few times but was now terrified of them. While taking off on his last flight the return spring on a rudder pedal had broken. This allowed the pedal to fall aft, toward him, on the floor. The result was that he only had rudder on one side and the plane careened off the runway, stopping between two parked planes. With the pedal on the floor there was no way to get it hooked with his heel to lift it back up. He missed the planes and only did minor damage to the Fly Baby, but wanted nothing more to do with Fly Babys.
I always wondered about the return spring but had assumed that if it broke my feet would be on the pedals and there would be no problem, bad assumption. Without the return spring the rudder cable pulls it aft to fall on the floor.
I mocked up a simple stop on the aft side for the pedal to fall against. There is no load on the pedal except it's weight and the weight of the cable so I made them from 0.040" aluminum.
I Alodined the aluminum to to protect it and screwed the stops to the floor. With the pedals reinstalled they stop at about a 60 degree angle aft. This is as far aft as the return spring normally allows.
We used some old CUB rudder pedals but this idea would work with the standard pedals.
The rudder cables were slowly sawing through the plywood gussets in the corners of the cockpit bulkheads. Originally my plan was to use CUB split nylon cable guides. I filed out the holes to make room for the guides and then ran the new rudder cables. Unfortunately the CUB guides are only 3/4" long and the bulkhead is 1" thick. I didn't want to remake the cables so I needed something which could be installed like the CUB guides.
I thought of machining some longer guides but really didn't want to go to all that trouble. Instead I found some 1/2" and 5/8" nylon tubing connectors at the hardware store and Tractor Supply. When I filed out the holes I didn't make them all the same size, for whatever reason, so the 5/8" fit 2 of the holes and the 1/2" fit the other 2 holes. I could have filed out the holes but I was worried about nicking the cable with the file.
To install the guides I split them on one side with an Exacto saw. This allowed me to pry the split open to slip it over the cable.
With the split on the opposite side from where the cable rubs, I safety wired the guide to the bulkhead. The barbs on the coupling make nice grooves for the safety wire so the guide won't slide fore and aft with cable motion.
On the first one I used 0.040" safety wire. This was hard to work with so I used 0.032" wire for the rest. I think I got the wire tighter with the smaller wire.
If these wear out I can easily replace them.
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