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Tight Bearing-Com-3-5?s

N

N14KR

Active Member
Working in Section 15 (Rear Spar) right now. I built the four aileron hinge brackets (inboard and outboard) including the two from the SB 16-03-28.

When assembling them, the came together nicely and had no problem inserting the Com-3-5 bearings into the Aileron hinge brackets. Then I clecoed and riveted them together as instructed and there is no noticeable gaps between the bracket pieces.

I noticed that in two of the hinge brackets, the bearing swivel very easily. But in the other two, they are tight and do not swivel very easily. Is this a problem?

I sprayed some LPS2 and made no difference. I?m concerned this will create problems down the road for me as I?m a first time builder and not sure of the implications of those bearings feeling tight and not swiveling easily. I can get them to swivel if I insert a punch and move them, but they are not easily moveable by hand, unlike the other two.

Appreciate insights from those more experienced than I.
I looked for similar questions from others but couldn?t find anything.
 
[email protected] said:
Working in Section 15 (Rear Spar) right now. I built the four aileron hinge brackets (inboard and outboard) including the two from the SB 16-03-28.

When assembling them, the came together nicely and had no problem inserting the Com-3-5 bearings into the Aileron hinge brackets. Then I clecoed and riveted them together as instructed and there is no noticeable gaps between the bracket pieces.

I noticed that in two of the hinge brackets, the bearing swivel very easily. But in the other two, they are tight and do not swivel very easily. Is this a problem?

I sprayed some LPS2 and made no difference. I?m concerned this will create problems down the road for me as I?m a first time builder and not sure of the implications of those bearings feeling tight and not swiveling easily. I can get them to swivel if I insert a punch and move them, but they are not easily moveable by hand, unlike the other two.

Appreciate insights from those more experienced than I.
I looked for similar questions from others but couldn?t find anything.
Click to expand...

I'm thinking that once the bolts get installed the main work of these bearings is rotation, not swiveling. How do they feel when just rotating? Maybe try tightening a bolt into the bearing and rotating it to test?
 
I found that the machining was off a few thou on some of the pieces. pull out the rivets and try a piece or two of packing tape in strategic spots between the two aluminum halves with clecos in. You can test with pieces of notebook paper. I only had one or two holes that needed a couple thou of spacing to allow the bearing to spin freely. I recall one spot where it spun fin with clecos, but not with the rivets in. Pulled the rivets and put tape there. The rivets apply MUCH more force than the clecos.

With too little clearance between the insides of the two machined holes, it will squeeze the bearing race and make it tight.

You want them to rotate freely, otherwise you may feel it in the stick force until the race wears enough to free it up. In my experince, if they dont swivel freely, they don't rotate freely either.

EDIT: Let me add that you don't want too much clearance, so go little by little. With too much clearance, the race will be allowed to spin and you don't want that either. The race should be snug, but not squeezed enough to add friction to the movement of the bearing.

Larry
 
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Ignore what I said. Alex and Larry clearly have more knowledge that I do on this topic. I did QB wings so never experienced this issue.
 
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Thanks for the input

Wow, appreciate the insights. I wish there something about this in the plans...
For such small parts, a lot work was put into them and I’m cringing thinking of having to undo all the work and rivets to make those bearings swivel correctly. Of course I will, but already thinking about ordering new parts and tackling the problem fresh versus the likely issues from having to undo so much.

ugghh..moments like this are real kick to the guts.
 
[email protected] said:
Wow, appreciate the insights. I wish there something about this in the plans...
For such small parts, a lot work was put into them and I?m cringing thinking of having to undo all the work and rivets to make those bearings swivel correctly. Of course I will, but already thinking about ordering new parts and tackling the problem fresh versus the likely issues from having to undo so much.

ugghh..moments like this are real kick to the guts.
Click to expand...

It feels that way now, but just move along with other stuff, get new parts, and build on! I've built three elevators, three flaps, and replaced innumerable parts for one reason or another. Stories to tell someday!
 
mturnerb said:
It feels that way now, but just move along with other stuff, get new parts, and build on! I've built three elevators, three flaps, and replaced innumerable parts for one reason or another. Stories to tell someday!
Click to expand...

Well said.
I relooked at those parts and only 1 of them has the issue. It?s easier to order the parts and rebuild the one. Not much $ and won?t take too long upon receipt.

Btw, the more i build on, the more i realize there?s a new vertical stabilizer in my future :p

Lucky enough that my elevators are good, but haven?t gotten to the flaps yet!
 
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