Rudder Pedal question.

[southwind32]

I assembled my rudder pedals today. The instructions call for 20-25 inch pound torque when installing the pedals onto the metal"T" portion of the tubing. There's a hard black tube that slides through the metal tubing. the black tube sticks out each end about 1/16 of an inch and suppose to act as a bearing surface. When I torque the long bolt down, the petals won't move. I have to back off the nut a little to get the petals to move freely. Seems like there should be a better set up for this. Is the black tube suppose to rotate in the metal tubing? mine doesn't. The instruction basically say to assemble it per the drawing. HELP. again LOL.
Thanks
Brian

[Cherrybark]

Brian,

That can be a finicky part of the build and you'll find a few descriptions in various threads. Takes patience to have smooth rudder pedals. You might substitute regular hex nuts for the nylocs that you will probably wear out through multiple remove and install cycles. Fire up some tunes or an audio book and enjoy hunting for the friction.

Here's a excerpt from my description of working with the pedals:


Of course, after torquing down the brackets, there was friction on both outboard pedals. As with the control stick, I was willing to patiently work to reduce the friction now rather than have it bug me over the years. There is a nice thread in the forum with ideas on straightening the torque tube. But, with my modest shop, I went with shims. Ended up with single washers under both outboard mounting brackets. The mounting screws are long enough to have plenty of thread through the nyloc washers.

To figure out where the torque tube was dragging on the bearing, I colored each of the four bearings with a black marker, torqued the mounting bolts, and swung the outboard pedals back and forth 20-30 times to rub away the marker. Removing the assembly and looking at the bearings showed where the tubes were rubbing. Shimming the outboard brackets as a first step reduced much of the drag. Then it was repeated "painting", mounting and working the pedals to identify high spots and slowly eliminate friction on the outboard pedals.

Only a small amount of material was removed from each bracket. In some cases, a "shoe shine polishing" with a strip of 1/2" 150 grit sandpaper shaped a bearing for a better fit. Where the weld spots rubbed the outer bearings, the "drill press lathe" and sandpaper were used to round the nose of the bearing or the offending weld spot was smoothed with a Dremel sanding disc.

Finally the bearings and torque tubes were cleaned with alcohol, lightly greased and torqued into place with new nyloc nuts. Twenty three hours on one part of the assembly! But I will be pleased with the light controls for years to come.

[efwd]

I think you are actually talking about the pedal itself and not the torque tube assy. I don't recall having an issue with that bearing. It sounds as though you have such a close fitting bearing through that tube that when torque is applied the bearing is expanding enough to bind up. You might make sure your tube is clean of any powder coating. Maybe even spin that bearing in the drill press and use sand paper to take material off. You'll need fine grit stuff to get the bearing smooth again. Thats what I did for the torque tube bearings. How accurate is the torque wrench? How critical is that torque in this application?
Eddie

[efwd]

I remember that the sides of the pedals are bent slightly narrower than the bushing. I think what that does is cause the bearing to push to the side of the pipe as torque is applied. I think I may have added a slight bend in further on the the sides of the pedals so that when I torqued it, the sides of the pedals met that bearing flush. I only bent in the segment immediately around the bearing. If you bend it at the face of the foot plate it just gets narrower. You need to make the surfaces that contact the bearing parallel.

[southwind32]

Thanks for the replies. I went out and looked things over again, and decided that yes, the black bearing tube must turn inside the metal tubing. So I chucked one up and sanded it down, smoothed up the inside of the metal tube also. Took a couple of tries, but after torquing, I have one pedal done. I also put a light coasting of light grease.
After reading the above, I know that I'm on the right track. Thanks again.
Brian

PS. Yes, I'll use new elastic stop nuts on the final torque.

[Cherrybark]

Nice catch Eddie. The other potential headache is a few steps down the trail if I remember the build correctly.

[southwind32]

Nice catch Eddie. The other potential headache is a few steps down the trail if I remember the build correctly.

and what might that be ??

[efwd]

Its the install of the torque tube assy. Thats what Carl thought you were talking about. When you go to torque down the assy to the floor you may find that it causes binding of the end bearings. I had a close fit of the bearings and ended up removing everything after readings Carls post months ago. I filed down the bearings on the drill press, polished them up and reinstalled so that now, My pedals move fore and aft freely without drag. See Carls post on what he did.
Eddie

[Cherrybark]

Cleaning up the friction on the rudder pedal assembly isn't hard, just time consuming while you work to reduce friction without introducing slop. Once you have the pedal and joy stick assemblies installed, the remaining control linkage goes quickly.

[southwind32]

When I bought this project, it was partially done up through and including the fabric covering. The rudder pedals wouldn't move, the brake cylinders fittings were open, found a nick in one of the rudder cables, and a nick in the tailpost, plus some other minor squawks. I decided to remove the fabric and took every thing off and start from scratch.
Built saddle for the nick in the tail post and welded in. Replacing the one bad rudder cable. The aileron/elevator assembly, took it apart, found to little bearings for the ailerons were bad, look good, but were very rough. I'm thinking when they were tapped into place the outter bearing cover must have been distorted to interfere with the inner bearings.
The rudder bearings had been pushed into the tubes, without any ability to rotate.
I've got the rudder bearing working smoothly on the bench, we'll see what happens when it all get's bolted down. Maybe I'll be lucky,,,,,,,,,probably not, so, trial and error, fit and file, fit and file.........I bought "o" ring kits from Mattco for the brake cyliners and taking them apart and resealing them, since they're about 9 years old. The one, I've done so far, actually looked good, and the o rings were fine, but still replacing them.
Thanks again, for everyones input, it's greatly appreciated.
Brian

[rwoneill]

Bringing this post back to life. I'm working on the rudder pedal bearings. I had to sand some pretty big burrs out of the actual tube, and I sanded down the bearings to get them to fit smoothly.

I then went to slide the bolt in to see if it would fit with the bolt inserted. It turns out that none of the long bolts are straight. Thus, none of the bearings fit anymore with the bolt inserted.

Should I go through and re-sand all the bearings with the bolts in? Or is it possible that I just got a bad batch of bolts?

[Doggitz]

I had a similar problem and agonized for about a week (SS 7). No matter what I did, I could not get the rudder pedals to pivot freely on the “T” part of the assembly. I initially sanded down the bearings, but found that the internal diameter of the “T” was not constant as the bearing would slide easily in part of the “T”, but not in other parts. I removed all of the powder coat that I could get to, but nothing worked.

i believe that the design of the pedal pivot is for the bearing to be clamped in place with pedal rotating around the bearing (I could be wrong and invite any comments). Fortunately, I live close to Efwd - who is a regular contributor to this forum. He suggested that I use drilled bolts with a castellated nut and a cotter pin. This allows the bolt to rotate alleviating any interference of the bearing with the “T”. It worked perfectly ! You do not need to torque the castellated nut, just screw it on until the cotter pin hole appears and put in the pin. I’m sorry, I didn’t write down the length of the bolt, but I believe it was the same as the drilled bolt. I used some grease between the bolt and the bearing. One thing you should be aware of, as pointed out by a technical advisor friend, is that because there are no bushings on the rudder pedals where the bolt assembly goes through, over (many) years, the holes in the pedals will wear and need to be replaced. I will add this to my yearly inspection. I hope this helps.

Fred
Building 7 SS
Plan 914 and G3X