R

rvbuilder1

Active Member
RV-4 issue
Doing my annual I found the rear jamnut to the rod end on the F440 pushrod tube loose. The F440 is the tube that goes from the rear seat stick to the bellcrank in the back of the fuselage where it connects to the F441 which is the large tube that goes all the way back to the rear of the plane connecting to the elevators.
When I tightened it I could not get full travel left and right for aileron movement. Looking at it when I move the sick full left and right the F440 rotated and stopped at about half full travel. When I pushed harder to get full left/right it loosened the jamnut again? Moving the stick the other way tightened the jam nut. The drwaing shows no jamnut called out for this end but it does on the front end.
The drawing shows a revision 7 that changes the rear rod end to a Heim F3514M which is what I have installed. There is nothing in my manual that discusses this as an issue
Scratching my head as I am quite sure that it should not be rotating in the rod end when I move the stick left and right?
Any thoughts- I have a message to vans via e-mail but I thought I would ask the RV4 folks also
 
Have you got the small steel washers on the bearing to give the bearing a little more room to pivot with a roll input? If the rod end bottoms out at the bellcrank stick force on the pushrod can rotate the pushrod about the bearing threaded end.
 
just talked to Vans. I had the wrong washer on. I used the 5702-95-030 ( large washer). I should have used the 5702-75-060 very small but 060 thick each side. This allows the tube to move and not hit the bell crank ears.

Problem solved but a PITA to solve in the rear of the fuselage
 
Just Curious

Im currently connecting up my elevator control tubes ( pushrods). The plans call for 2 washers to be installed, 1 each side of the heim joint ( see picture attached). The fitting that the heim joint slides into doesnt have enough spacing for one washer, let alone one each side as the plan indicates.

Im assuming that I have to expand (force) the fitting open enough to allow those 2 small / thick washers to be installed ? If the washers are 60 thou each thick, this means I have to expand the fitting by almost 1/8". Sounds butcherous.

 
spacer insertion

on my -4 i had to use some ''persuation'' to get those washer. one fit easily but his friend need some expansion. on your picture above the arrow, it seems like a break in the weld? may be my eyes are playing trick on me.

on the plan, it should provide some dimension.

good luck

Michel
 
Good point checking the plans

Hi,

Thanks for your reply, I'll check the plans as you suggest.

Im assuming that my only option will be to expand the fitting, Ill post another photo once im done.

Thanks again.
 
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