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  #1  
Old 09-04-2017, 12:03 PM
Djgeib Djgeib is offline
 
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Location: Fernandina, Fl
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Default Aileron bracket bearings??

3 out of 4 aileron bracket bearings move with complete freedom of movement after being riveted in their respective brackets. The fourth one, right outboard, is stiff to the touch. Don't ask me why I didn't check it before driving rivets.
Do I need a new bearing, bracket or both? I suppose I'll spend tomorrow morning taking out 12 rivets. Five really long ones unless someone has any better ideas.
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Old 09-04-2017, 12:16 PM
rvbuilder2002 rvbuilder2002 is offline
 
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Occasionally a slightly tight bearing can be loosened up using some shims and a bench vise to apply a small amount of side load pressure to the pivot ball and move one of the bearing races very slightly. Worth a try before taking it apart.
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Old 09-04-2017, 06:04 PM
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1001001 1001001 is offline
 
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Quote:
Originally Posted by Djgeib View Post
3 out of 4 aileron bracket bearings move with complete freedom of movement after being riveted in their respective brackets. The fourth one, right outboard, is stiff to the touch. Don't ask me why I didn't check it before driving rivets.
Do I need a new bearing, bracket or both? I suppose I'll spend tomorrow morning taking out 12 rivets. Five really long ones unless someone has any better ideas.
I had this happen on my -10, and I checked the bearing movement thoroughly by clamping before riveting. Fine before riveting, stiff (on one bracket) after riveting. I figure the process of riveting introduced some warpage in the bracket, even though I riveted in a "random" pattern.

I put the bracket in a bench vise (with protective aluminum jaws) so that the bearing end was in the jaws, and tapped lightly with a dead blow hammer on the opposite end, testing the bearing movement after each blow. Doing this, I was able to find out which hits affected the bearing (tighter or looser) and then got it to run loosely. It seems like if you prime the brackets, that you ought to make sure that there is very little primer build-up on the bearing "socket" in the bracket plates, that might have something to do with excess or uneven pressure applied during the riveting process.

Anyway, I was able to get the bearing to run freely by undoing the warp in the bracket.
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Old 09-04-2017, 06:23 PM
scsmith scsmith is offline
 
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Quote:
Originally Posted by rvbuilder2002 View Post
Occasionally a slightly tight bearing can be loosened up using some shims and a bench vise to apply a small amount of side load pressure to the pivot ball and move one of the bearing races very slightly. Worth a try before taking it apart.
Scott, how does this happen? The outer race was one piece, although one side is 'crimped' in the manufacturing process. Do you think clamping pressure in the pockets could be enough to add to the crimp and tighten up the bearing?
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Old 09-04-2017, 07:57 PM
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az_gila az_gila is offline
 
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Try a small amount of penetrating oil first to make sure it's not caused by a little hidden corrosion.
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Old 09-04-2017, 08:01 PM
rvbuilder2002 rvbuilder2002 is offline
 
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Originally Posted by scsmith View Post
Scott, how does this happen? The outer race was one piece, although one side is 'crimped' in the manufacturing process. Do you think clamping pressure in the pockets could be enough to add to the crimp and tighten up the bearing?
I don't really know why it happens but I have seen it a couple of times. I imagine that with the very close fit of the bearing to the races (likely only .0002-.0003 or so) even the smallest distortion of the bearing body can likley induce some friction.
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Old 09-05-2017, 07:47 PM
Djgeib Djgeib is offline
 
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I appreciate the quick replies. I went to the shop today. Had put oil on it last night. Not much better. Tried to manipulate with shims, clamps and a rubber mallet with out much luck. Removed the two rivets closest to the bearing and that freed the bearing to spin unrestricted. Moved the bearing around in its socket. Clamp it tight where the rivets would go. Much better but I can still feel some resistance.
Called Vans to get their opinion. He said I might not notice it with aileron attached. Think I'll put the aileron on tomorrow. If I can feel resistance when I move the aileron I'll remove the bracket get a new one and a new bearing. If I can't feel it I will live with it.
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Old 09-05-2017, 07:53 PM
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Quote:
Originally Posted by Djgeib View Post
I appreciate the quick replies. I went to the shop today. Had put oil on it last night. Not much better. Tried to manipulate with shims, clamps and a rubber mallet with out much luck. Removed the two rivets closest to the bearing and that freed the bearing to spin unrestricted. Moved the bearing around in its socket. Clamp it tight where the rivets would go. Much better but I can still feel some resistance.
Called Vans to get their opinion. He said I might not notice it with aileron attached. Think I'll put the aileron on tomorrow. If I can feel resistance when I move the aileron I'll remove the bracket get a new one and a new bearing. If I can't feel it I will live with it.
I actually removed the rivets and reinstalled them twice, with the same binding. I thought it must be the bearing, but I was able to make it go away almost completely by adjusting the bracket as I mentioned above. Weird. I was extremely careful to make sure the bracket pieces were perfectly flat before riveting them. I used my granite measuring block and the bracket pieces were flat to within a few thousandths before riveting, but I still had the binding problem. That's why I think it might have something to do with excess primer or something else taking up space in the bearing socket in the outer "sandwich" parts of the bracket. I didn't want to keep drilling out the rivets and trying again because it was just a matter of time before I would damage stuff during the rivet removal and have to rebuild the bracket completely.
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Old 09-05-2017, 08:41 PM
cczarnik cczarnik is offline
 
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Working on my aileron brackets tonight, noticing slight bowing from the stamping process. Want to avoid the issues in this thread- could this be related? Any tips on straightening them out?
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Old 09-05-2017, 09:13 PM
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Originally Posted by cczarnik View Post
Working on my aileron brackets tonight, noticing slight bowing from the stamping process. Want to avoid the issues in this thread- could this be related? Any tips on straightening them out?
The plans for the -10 specifically mention this warping, and discuss flattening the parts before putting the brackets together. I used my granite plate and a dead blow hammer to gently straighten them, along with a vise and hand pressure. I think they have a spec for how flat is flat enough but I can't recall the specifics right now.

EDIT: I dug into the plans and I must have imagined that. I can't find a reference to flattening them there, but I'm sure I read it somewhere. Maybe Section 5, or more likely something here at VAF... Or maybe it was in the docs that came with the SB kit for the upgraded aileron bracket.

Last edited by 1001001 : 09-05-2017 at 09:20 PM.
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