anyone use ball joints on their elv ,ail ,etc the same as the ones used on helicopters.

I believe the stresses involved in working the control surfaces are way too much for any ball/cup type snap on linkage.

Don

Gee, several golden age full scale airplanes used them for the aileron controls, and very successfully too.

Bill, AMA 4720
WACO Brotherhood #1

I'm no expert on heli's but my last experience with them show the ball joints using a thru bolt to hold them secure. I use those on elevator and rudder with no problems. I DONT use the push on cup type ball joints on any control surface. The cup types are ok for throttle, maybe some other non flight servo.
Edwin

The ball links are used a whole bunch on the GS aerobatic models but with a caveat or two...

You usually only find them on the servo arm, not the control horn and those servo arms are either metal or some other high strength material which can take the torsion being applied to them from the control surface. Never use them on the control surface horns unless you have a model using two horns parallel to each other on each surface and the ball link is in between them.

They are also used a lot for metal control rod throttle linkages on the gasser (two stroke gasoline, not glow) engines which helps to isolate the electrical impulses from the engine's ignition system to the radio equipment. Lots of times you'll find them on both ends of those installations, but they also have a metal or HD servo arm and usually a metal arm on the carb as well.

I use them only on my throttle, eliminates push rod alignment problems.

Well... I have never used them on a GS... but I built many a pylon racer with ball internal ball links on the elevators within the tail and flew them though very high-G turns at 170+. They were still attached after the eventual 170+ crashes! Good enough for me. The secret is the geometry must be correct... ie.... you don't want them to travel in a way that will pop them off after contact with the ball shaft. There are some excellent quality ball joints available and if used in a manner that does not exceed design limitations... they are OK. That said... I always prefer a clevis in general.

Perhaps there is a bit of confusion here which I thought was addressed by aaxiss; I'm not talking about the type that snaps on and off which is what it looks like you're referring to? Maybe I'm the one that's confused and the original poster was inquiring about the type that snap on and off? I've used those on glow model throttle linkages.

The ones I'm talking about are mounted with a screw through the horn/arm using a standoff spacer and usually have a lock nut installed on the backside as well. Like these.....

Zeeb,

I would reccomend using a flat washer that would keep the ball firmly in place, yet small enough to not cause binding.

Bill, AMA 4720
WACO Brotherhood #1