Safety wire ?

[RVG8tor]

The Dynon roll servo comes with drilled bolts. The two bolts that hold the control rod between the aileron bell crank and the servo, do you safety wire these two bolts together? I ask because one bolt goes into a nut plate and the other has a nylock nut. Also the rod moves around the bearing.

If it does get safety wired, is there a best practice for this type of connection. Sorry picture since I am at the hanger and on the iPhone.

Cheers

[bruceh]

The instructions for the pitch and roll servos are slightly different. Both the pitch and roll servos get the safety wire.

Excerpts from the RV-9 documentation:

From the PITCH servo instructions:
All AN bolts supplied by Dynon have drilled heads for use with safety wire. With the servo and bell crank additions in place, torque all fasteners back to original installation specifications and add safety wire where needed.

From the ROLL servo instructions:
With the servo and bell crank additions in place, torque all fasteners back to original installation specifications and add safety wire throughout.

[Flying Scotsman]

I don't get this...how do you safety wire these drilled-head bolts?

I'm installing the pitch servo now, and everything is in but the safety wire on the bolts holding the servo to the bracket, and safety wire on the bolts through the servo arm/rod end and bellcrank/rod end for the servo. I can see how to do the 3 bolts holding the servo on (it'll be a pain, but doable), but what do you do with the two drilled-head bolts on the pushrod?

[Zazoos]

Originally Posted by Flying Scotsman

I don't get this...how do you safety wire these drilled-head bolts?

I'm installing the pitch servo now, and everything is in but the safety wire on the bolts holding the servo to the bracket, and safety wire on the bolts through the servo arm/rod end and bellcrank/rod end for the servo. I can see how to do the 3 bolts holding the servo on (it'll be a pain, but doable), but what do you do with the two drilled-head bolts on the pushrod?

I am wondering the same thing. Not sure what to safety wire the drilled bolt head to that goes through the pushrod.

[RV7A Flyer]

So aren't these simply bolts which go through washers and rod ends and such and get a nylock on the other end? Sort of exactly like all the other pushrods and such on the control system, which themselves don't have safety wire? i.e., the Nylock is torqued properly and the whole kit and caboodle captures the bearing, as it should, which then turns inside its race.

I have the Dynon servos and I don't recall safety wiring these bolts. Not at the hangar, so can't check, but I'm pretty sure not.

[Greg Arehart]

I don't recall whether I safetied either of these, and the one in the servo seems to have no reason to safety, since the nut is still rotatable. But if you want to safety them, simply safety the servo one to one of the holes in the arm (be sure there is complete free movement of the arms as necessary) and do similarly with the one on the bellcrank by drilling a small hole somewhere in the bellcrank (again, make sure there is no interference with free movement).

My opinion only.

[lr172]

Not sure why you would want to put safety wire on a bolt that has a nylock. Nut. You do need to safety the bolts into the servo, as they have no other method to combat vibration.

Larry

[Scott Hersha]

Safety wiring those two bolts would serve no purpose. You want to keep the nut from coming off, which is what the nylock is for. If you?re concerned about that, you could use a castellated nut with a cotter pin to make the nut more secure, but the goal isn?t to keep the bolt from turning (it shouldn?t turn if torqued properly), it?s to keep nut holding the pushrod on in place.

[WingsOnWheels]

I did not safety wire the rod-end bolts.

[FinnFlyer]

Originally Posted by Greg Arehart

I don't recall whether I safetied either of these, and the one in the servo seems to have no reason to safety, since the nut is still rotatable. But if you want to safety them, simply safety the servo one to one of the holes in the arm (be sure there is complete free movement of the arms as necessary) and do similarly with the one on the bellcrank by drilling a small hole somewhere in the bellcrank (again, make sure there is no interference with free movement).

My opinion only.

I would be wary of doing that. You have motion of servo arm that could cause the safety wire to wear into the servo arm.

I my opinion Dynon is doing a disservice in supplying those bolts with drilled heads.

Finn