View Full Version : TruTrak Pitch Servo Plate Intall Question
05-16-2008, 06:31 PM
I'm looking to install my AP over the next week or two and was wondering how many of you who are flying riveted it to the bottom skin.
I've been told this is not necessary if you add a few more rivets to the F-729A Bell Crank Rib but would like to hear what others have done.
05-16-2008, 06:44 PM
I have a similar question, what about using AN3 bolts instead of rivets, also not riviting to the bottom skin, just bolting to the bellcrank rib. Probably using 4 or 5 AN3 bolts instead of the specified rivets.
05-16-2008, 07:04 PM
I think you can use AN3 bolts if you don't want to rivet it. Check your servo, there is probably a shear pin which will brake if you really need to muscle control from the autopilot.
For me, squeezing a few extra rivets on the thing sounds easy enough to do.
05-16-2008, 08:27 PM
I used bolts on the -6a to attach the pitch servo mounting plate since it was installed after it was completed, it was much easier.
I have riveted the plate to the rib on the -7a with several additional -4 rivets.
Both are very secure, and I really don't think it needs to be riveted to the bottom skin.
05-16-2008, 08:36 PM
I am flying with my TruTrak and love it. I did rivet it to the bottom skin, it wasn't difficult to do, but attaching it only to the bellcrank rib would be plenty strong.
The breakout force for the servo is something you adjust in-flight, and if you follow their procedure, it doesn't take a lot of force to override the servo. You adjust it to your liking. If your're thinking two hands on the stick to override the servo - forget it! Right now if you moved my controls with the servos engaged you'd think they were a bit stiff (and jerky due to the stepper motor), but would have no problem whatsoever moving them.
05-19-2008, 09:50 AM
There is no need to actually rivet the bracket to the bottom skin unless that is what makes you comfortable. The bracket in our RV-9 is simply bolted the bellcrank rib with AN hardware. Thanks!