rudder pedal freeness

[ken nougaret]

I got my rudder cables hooked up now that the rudder is on. But my pilot and copilot ouboard pedals wont spring forward on their own. I removed the outboard torque tube bearings and sanded on them some more to give an easier fit but it didnt totally fix. Its an SS with adjustable pedals and brakes on both sides.
Will this be a problem if i leave it this way?
Thanks, ken

[Dave S]

Hi Ken,

I had pretty much the same experience at first on our early model S7.

There might be several opinions on this. I know of more than one person who has had some challenges with getting the pedals to move freely.......sometimes the alignment changes slightly just enough to make them bind when mounted on the floor even though the pedal moved smoothly before mounting.

One thing to consider is if the torque tube sticks on the bearing, there is a lot of leverage that can be put on the bolt running through the bearing to the mounting bracket......not beyond possibilities the bearing retaining bolt could end up turning in the bracket where it should not be; and, cause wear on the bracket hole and bolt that would be preferable to avoid.

Depending how a rudder pedal sticks & various movement with the other, there is a possibility of the cable getting slack and causing interference somewhere with some other structure or rubbing on something.

I found that by sanding the bearing to a very slight barrel shape spinning it in the drill press - that seemed to minimize the sticking after the assembly was mounted to the floor. Also, using progressively finer sand paper seems to reduce the friction...I think I ended up using 400 or 600 W/D for the last pass on the bearing after it got to the right diameter.

Sincerely,

Dave S

[ken nougaret]

Ok, dave. Maybe ill spend more time on the bearings. They're hard to sand. I just dont want to go to far.

[n85ae]

Check your alignment of parts, a good chance when the bolts are tight it
pulls out of alignment and binds. Creative use of shims might fix you problem.
Which is a better fix than sanding (assuming they don't bind when you have
them in hand).

Jeff

[Dorsal]

I agree with Jeff, had to shim mine to get them to remain free when tightened.

[ken nougaret]

Anybody gone with stiffer springs?

[jtpitkin06]

It is not only possible but mandatory that your adjustable rudders spring back to keep tension on the cables and keep the cables on their respective pulleys. I found the rudder torque tube fitting process to be the most tedious of all assemblies on the Kitfox. Keep at it until you get smooth operation.

There are lots of postings on fitting the torque tubes.

Using stronger springs would be a band-aid fix, but at the cost of losing rudder feel. When pressing down on one rudder pedal you must overcome the spring tension on the two opposite pedals as they travel aft. You also must overcome the spring pressure when using the manual adjust levers. Concentrate on getting the binding out of the pedals.

Remember that airframes bend and flex in flight. If you have binding on the ground it could be worse in flight.

Don't get discouraged, we've all had to work the kinks out.

JP

[ken nougaret]

just found the thread on rudder pedal friction; i should have looked it up earlier. i'm going to pull the whole system back out of the plane and check it on the bench. i'll get it right. ken

[MotReklaw]

Think I will too, Ken. I have friction on just one side. Thought it turned freely before torquing it down. I may have an alignment problem....

Tommy (temporarily in El, Paso, TX)

...i should have looked it up earlier. i'm going to pull the whole system back out of the plane and check it on the bench. i'll get it right. ken

[ken nougaret]

Well, i didnt have an alignment problem. I had to sand on all my bearings and inner torque tubes. But now it works slicker than snot.