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!

Stabilator balance - binding?

jsalley

Well Known Member
Patron
After installing the stabilator on my 12iS, I feel that it might be binding, and am concerned that I won’t be able to get it properly balanced. During installation, prior to inserting the two pivot bolts but with some temporary “space holders” to keep the bolt holes aligned, the stabilator naturally went trailing edge up (counterweights have not been trimmed). When the bolts were inserted and properly torqued, it stays in whatever position I put it in, although it doesn’t offer much resistance to either up or down travel. Loosening the bolts doesn’t change it. The cables are tensioned to 35# (KAI states 35-45#). Van’s builder support says the bolt torque doesn’t matter since the bearings are not affected by the bolt tightness. They went on to say that they would consider the stabilator to be balanced since it stays wherever it is manually moved, but I’m not so sure. The stick force doesn’t seem excessive. Any thoughts from the RV-12 crowd?
 
Mine was very close to being balanced right out of the box. So close that I didn’t bother trimming the counterweight.
 
Sounds like you hit the jackpot with respect to ground balancing. Agree w/ JSalley's question about how it feels in the air. My bet is that it's going to feel just fine.
 
How does it fly (assuming it’s flying)?
Flies just fine. Stabilator control is smooth. Once you attach the linkage for the trim motor it tightens things up slightly from what I noticed. Maybe it was just in my mind. My understanding is that the counterweight is there for flutter mitigation.
 
How about.. build a simple jig off of the airplane, one with no binding force, and balance it there? In reality, a bit off perfect balance will not be noticeable.
 
How about.. build a simple jig off of the airplane, one with no binding force, and balance it there? In reality, a bit off perfect balance will not be noticeable.
I’m planning to do that when the stabilator comes off for paint. Just want to be sure I’m not missing anything before first flight.
 
related but different:
I’ve seen someone reinstall the tailcone slightly crooked, resulting in the elevator rubbing on the tailcone in certain elevator positions.
 
related but different:
I’ve seen someone reinstall the tailcone slightly crooked, resulting in the elevator rubbing on the tailcone in certain elevator positions.
No difference with the tailcone fairing on or off.
 
Back
Top