Torque tube

[ron]

Am installing the torque tube on my BCC but find the clearance between the bottom of the stick pivots and the inside base of the torque tube is only about 1/16".This is after grinding out a lot of metal off the elevator push rod.Can anyone tell me what is a normal clearance with the control stick in the normal position for level flight please.Thanks.

[ron]

Thanks guys I still have no answer,is my question not clear?Suprising a measurement is not available.

[T.J.]

More info needed. I have no idea what you want?
What's a BCC?

[tcraft128]

Thanks guys I still have no answer,is my question not clear?Suprising a measurement is not available.

You might try posting a picture of your problem. Where do you want the measurement from?

T.J, BCC is blind Carbon Copy or maybe Back Country Cub, IDK either

[skywagon8a]

Ron,
If you are saying what I think you are saying, 1/16" is enough. As long as nothing will hit to interfere with the full throw of the stick with a load on it. Make sure that the bolt and cotter pin can not catch while moving the stick.

[ron]

Thanks Sywagon8a,yoor help is much appreciated.Ron.

[ron]

tcraft,BCC could also be b.....y childish comments.

[skywagon8a]

...This is after grinding out a lot of metal off the elevator push rod....

Ron, This statement has me baffled. Where was the push rod hitting? I can not picture what the push rod would have been rubbing on enough to need grinding. I found that the cotter pin which is on the bolt that holds the push rod to the bottom of the stick socket sometimes touches with a side load on the stick.

[tcraft128]

The piper drawing shows a Clevis Bolt, AN24-13, at the lower pivot point that provides the clearance for the inside. See piper drawing 12237 on Supercubproject.com. I found that if you use a standard AN bolt it is a little tight in there, but with the correct bolt (screw head) and a low profile castle nut, there is plenty of room. Ron you might check the height of the stub. There are two different versions and maybe you don't have the right ones. The versions differ in the length from the bottom where the rod connects to the pivot point that connects to the torque tube.

[ron]

Thanks guys have several photos I am trying to put on the forum.Several expert piper cub engineers have looked at my cub and have all stated that the push rod ends are very poorly made and have been literally beaten out then welded.When I first connected the elevator system up I could not move the elevators at all as the connecting rod connecting the two pivots was stuck in the bottom of the torque tube.I had to grind the ends down so much that itmade one great mess that would require welding.Jay is sending me one of his pushrods.If this fails to fix I will try one of his torque tubes.Incidentally the measurements of the BCC are no where near the standard piper super cub.I will ask my friend to post some pictures.Thanks one and all for the help.

[ron]

Thankks Tcraft,the pivot stubs are all the same size and Jays are identical with BCC.Hope you c an see some pictures I am trying to upload.

[MainlandCub]

Hi Guys,

Ron has sent me some pictures to upload. I hope that helps you figure out what is going on with his Back Country Cub.

Thanks,
Andrew.

[Steve Pierce]

The piper drawing shows a structural screw AN24-13

Jay they are actually clevis bolts.

I will try and get a picture of a Piper torque tube.

[tcraft128]

Jay they are actually clevis bolts.

Got it. Clevis Bolt.

[Steve Pierce]

Same strength as an AN bolt but usually used in shear where the fastener can't get tightened too much and hurt the part or allow for proper clearance.

[tempdoug]

http://www.supercub.org/forum/showth...ht=torque+tube Ron, if its not right call them and send it back and work on something else. Heres some measurements in this thread. My 2 cents.

[MainlandCub]

http://www.supercub.org/forum/showth...ht=torque+tube Ron, if its not right call them and send it back and work on something else. Heres some measurements in this thread. My 2 cents.

Doug,

I don't think they're on talking terms anymore..........

Thanks for posting that link, I wanted to point Ron in that direction as the Piper drawings he has are for the old straight stick type stubs and torque tube.


Ron has one of the most senior LAME's in New Zealand helping him on this project, but with something like the torque tube and sticks where Back Country have varied from the original Piper some input from those who have done Back Country Cubs would be invaluable. I'm pretty sure there are no other Back Country Cubs in NZ. Looking at Piper drawing 12237 it appears the push-pull tube is too low in the torque tube on Ron's parts.

Cheers,
Andrew.

[skywagon8a]

Thanks for posting that link, I wanted to point Ron in that direction as the Piper drawings he has are for the old straight stick type stubs and torque tube.


Ron has one of the most senior LAME's in New Zealand helping him on this project, but with something like the torque tube and sticks where Back Country have varied from the original Piper some input from those who have done Back Country Cubs would be invaluable. I'm pretty sure there are no other Back Country Cubs in NZ. Looking at Piper drawing 12237 it appears the push-pull tube is too low in the torque tube on Ron's parts.

Cheers,
Andrew.

I did not realize that Ron is in New Zealand. I can understand the frustration in having to deal half way around the world on this type of thing. Ron, why don't you cut off the two tabs on the stubb at the weld and reweld them high enough to provide the clearance that you need? How is the rear one? Is it rubbing also? My plane is a BCC and fit just fine. The parts were made by Javron before the move to Wyoming.

[Steve Pierce]

Here is an original Piper 1981 vintage.
DSCF1737.JPG

DSCF1739.JPG

[Iflylower]

That's unfortunate. It's an experimental, so fabricate away. Looks like the easiest fix is pull the rear stick. Grind or strip paint. Weld the holes closed and redrill and ream slightly higher. It's a rear stick and likely not used much, I don't think you'd notice any leverage difference, but there could be the slightest heavier control in the pitch. But, you'd be fixed.

Also, you could try and squeeze the sides of the torque tube in a vice to elongate the bottom, just where the stick, pushrod, and clevis come together. Stay away from the rear bearing. It's not my first choice, but could be a quicker, easier fix. But, that'd be easier to tell if you were holding the parts in my hand.

Problems always arise. That's why they call 'em homebuilts.

[12 Geezer]

Probably don't wanna squeeze the sides of the torque tube. It's already a somewhat tight fit on the side, for the clevis bolt (the nut side) even with a shear nut. At least it is on mine - - - I agree with relocating the hole - not a big job, and slightly shorter stick throw in the back would be an improvement, at least in my opinion.

[mike mcs repair]

...why don't you cut off the two tabs on the stubb at the weld and reweld them high enough to provide the clearance that you need?...

that would be my first try too.....

[MainlandCub]

I did not realize that Ron is in New Zealand. I can understand the frustration in having to deal half way around the world on this type of thing. Ron, why don't you cut off the two tabs on the stubb at the weld and reweld them high enough to provide the clearance that you need? How is the rear one? Is it rubbing also? My plane is a BCC and fit just fine. The parts were made by Javron before the move to Wyoming.

Thanks, I was hoping you would chime in. I've seen your Back Country Cub on supercub.org. I hope Ron can forgive me for commenting. Ron has owned several Super Cubs, but I'm sure this is his first homebuilt, so it is all uncharted territory for him. You can see pictures of two of his previous Super Cubs at these links. I can tell you with absolute certainty that Ron has owned all the yellow three seat Super Cubs in New Zealand!


http://1.bp.blogspot.com/-xsoje5bLlw...A+02-01-09.JPG


http://4.bp.blogspot.com/-uucH48iJrsM/TcpaP_otqxI/AAAAAAAAFtw/xo1gcouV7Tk/s1600/BVO+RT.24-02-06.JPG


Ron lives in some of the best Super Cub country in New Zealand, but it means he is a bit isolated and may not have access to someone who can readily do the welding. I'm sure he appreciates the input that will help him choose the best way to move forward.

Andrew.

[Iflylower]

Probably don't wanna squeeze the sides of the torque tube. It's already a somewhat tight fit on the side, for the clevis bolt (the nut side) even with a shear nut. At least it is on mine - - - I agree with relocating the hole - not a big job, and slightly shorter stick throw in the back would be an improvement, at least in my opinion.

The squeezing idea as per my post is just based on judgement, while you hold the fixture and judge the big picture....

I looked at your 4 pics again. AND, from what I see, that's both front and rear stick. Looks like you have the same problem both ends. I would not squeeze the sides to elongate in this situation, because your push pull rod will probably still be too low through much of the tube.

I'm back to the remove BOTH sticks and weld the holes closed, grind em smooth, redrill and ream slightly higher and cut off/radius the lower part of the tabs for clearance. I think you have some work ahead, but it shouldn't be too bad. By the way, the stick would have more leverage with the elevator and the limit stops shouldn't be affected as they are back on the tail anyway. Plan it carefully and it should work out well. While I like to weld, I think that redrilling the holes might be easier for quality control and proper positioning of the holes, parallel and front/back. Either will work, I just like easier and better results.

[ron]

THANK YOU ALL for your contribution to our torque tube problem.Have taken it all on board and as I am not a welder I am considering getting the complete assembly from Jay.It would probably be the best scenario for myself.