Good Morning Everyone. I am starting to work on the flight controls on my wings and was assembling the aileron bellcranks. I have one where the brass slid in easily and another where the brass has to be pressed in. Looking at the directions, it say that the brass needs to extend beyond the end of the bellcrank by 1/32" which makes me think that the brackets are going to clamp down on it. Which is right? Does it matter if the brass is tight inside the bellcrank? Thanks!
Van's Air Force
The definitive Van's Aircraft support community! Buying, building or flying an RV? Join our exclusive family of mentors and enthusiasts!
Aileron Bellcrank Brass Bushing Tight?
- Thread starter bob865
- Start date
The design is such that the steel of the bell-crank rotates around the outside of the brass bushing, the bushing being clamped tight in the mount by the bolt - so yes, you need to press the tight one out and take the outside diameter down ever so slightly. It helps to ream the inside of the bell-crank tube to make sure it isn’t slightly deformed or has a bump in it (from welding). It’s fiddly work, but well worth getting it right.
It's not unusual to find power coat or other FOD inside the bellcrank. Like Paul said, remove the bushings, clean out the bellcranks. Maybe even ream and polish the inside. I polished the exterior of the bushing, but doubt it's noticeable once all the linkages are assembled.
FYI, control column has similar bearing arrangements. Unless it's a 14.
FYI, control column has similar bearing arrangements. Unless it's a 14.
Another option you might want to consider is to upgrade to the ball bearing aileron kit offered by Sky Designs. I installed them in my RV-8 and absolutely love them! They are well designed and work really smoothly. https://www.skydesigns.aero/products
I went with the SkyDesigns kit like @Skykingbob . But that was after I'd carefully fitted the brass bell crank bushings, smoothed insides of the bell crank (where the bushings go) with 400 grit sandpaper on a simple homemade mandrel and then polished the bushings in a vibratory tumbler with walnut media. They were silky smooth.
But, when Ken showed me his aileron bell crank kit, I was blown away. There's no slop at all, and smooth like butter!
But, when Ken showed me his aileron bell crank kit, I was blown away. There's no slop at all, and smooth like butter!
The brass bushing should be longer & extend out each end of the bell crank. Also don’t over torque the bolt as to squash the brass bushing causing it to tighten inside the bell crank.
There should be no realitive motion between the brass bushing and the bolt.
Don’t forget to grease the inside of the bell crank and the outside of the brass bussing.
Carl
This really helps when freshening the lubrication with LPS (or whatever you use) at the condition inspections. Went with the Trio gold servo setup.
Last edited:
