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Rudder counterbalance torqueing

idubrov

Well Known Member
I was a bit overzealous torqueing the rudder counterbalance screws, which caused nutplate strip to bend a bit. The torque value was relatively low, less than 20-25 lbf*in that should be used for #10 bolts (I assume screw of the same size should be similar to the bolt?).

As I understand, the counterbalance has two counterbores due to the old method of attachment which used nuts.

What do you think? While everything is still open, I can take the nutplate strip out, straighten it and put some aluminum bushings under it. Or I can just keep it like that. The counterbalance is also attached with some amount of T-88 epoxy under it, so I don't think it should ever move.

See the attached image.
 

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The torque value for a An3 bolt is 20-25 INCH LBS not ft. lbs

Right. This is what I have, 20-25 lbf*in (pound force * inch). It's a torque screwdriver, I don't think it can deliver 20-25 lbf*ft.

P.S. The actual torque I got (before I stopped) is about 18 lbf*in (minus the nut plate friction).
 
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Bushings

Since you have access, I would take it apart and put bushings in or fill the space with some scrap lead.
 
Since you have access, I would take it apart and put bushings in or fill the space with some scrap lead.

Yeah, I decided to replace it. The strip actually started to crack, so I am glad I did.

Also, I got that satisfying click at 25 lbf*in (I estimated nut plate friction to be less than 5lbf*in, so this should get me into 20-25, not that it matters that much).

New parts:
 

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