Gear Actuator Safety Wiring

Just wanted some opinions.
I have drilled the the pain in the _______angled hole to safety wire the flap actuator to the rod end bearing a long time ago . Upon further review prior to final installation of the flap actuator assembly, there is very little material between the safety wire hole and the edge of the actuator tube due to avoiding the jam nut. If this is a significant concern? I was thinking of spot TIG welding the end cap onto the actuator tube. Has anyone had these apart? Also what is the failure mode if the safety wire doesn't hold the end of the actuator on? Seems to me there should have been a hole drilled perpendicular thru the end cap and shaft with a flush roll pin and safety wire installed not some little bit of metal holding the safety wire.
Just thinking,
Terry

No understand

Huh?........ Maybe a picture?

Terry,

What I did was remove the jam nut after lightly scribing its outline on the end of the actuator so I would know where to center punch for the drill. I threaded the .032 safety wire through the hole and then replaced the rod end and jam nut. Here are a couple of photos.





I recently converted from securing the safety wire to the drilled bolt head to a hole through the rod end as others have done. This is definitely the better solution as this way the safety wire is not stressed at all. My first idea of using the bolt head was causing the safety wire to move each time the flaps were actuated and would have eventually caused the wire to fail.

I copied someone's suggestion on these forums to drill the rod end.

Also used locktite on the threads. If the nut gets loose, the rod end won't turn with the safety wire in place.

Flap Actuator

bruceh said:

I copied someone's suggestion on these forums to drill the rod end.

Also used locktite on the threads. If the nut gets loose, the rod end won't turn with the safety wire in place.

Click to expand...

I did it exactly how you describe and after talking to Van's today I was over thinking it a bit.I was thinking it kept the base of the actuator from unscrewing but Ken at Vans said it is just kept the rod end from unscrewing and with the safety wire and loctite it should never be a problem.

Thanks guys back to wiring!
Terry

Pat Hatch said:

Click to expand...

I must not understand this - why would the wire not fatigue and break in this case?

Alex, I think you are right... it is possible for the back-and-forth play in the rod end to eventually fatigue the safety wire. I like Bruce's solution better. By doing it this way, you are eliminating the play in the safety wire itself. I may change over at the next condition inspection. I really don't see any reason why you shouldn't drill through the rod end, but if you're not comfortable with that, you're going to have to accept the slight play in the safety wire. Thanks for pointing this out!

[P.S. - I went ahead and changed from using the drilled bolt head to using a hole drilled through the rod end. This is a much better way to do it.]

If you relaying on the safety wire then no matter where you tie it to, if the jam nut comes loose, the right/left turn will eventually brake the safety wire.

The way I have drilled the shaft, it is close to the jam nut that the safety wire will prevent it to come loose. So, I rigged mine and noted where the jam nut will be in a tight position, then drilled it as close to it as I could. Now the presence of the wire acts as a stop and you can hardly take the jam nut off even with a wrench if the wire is in place.

So far so good but it?s been only 3 years and almost 400 hours. Time will tell

Hope this helps.

I think what he is talking about is that the bolt with the safety wire is stationary, i.e. the nut on the bolt torqued and it does NOT rotate. When the arm moves there is relative motion between the actuator shaft and the bolt/arm of the flap mechanism. Eventually the safety wire will break.

Mike,

You are right, of course. As I watch the flaps go up and down I can see the relative motion you are speaking of. In time it will cause the wire to fail, so I have re-thought this and now think it's a bad idea. The hole through the rod end is the way to go as there is absolutely no relative motion this way!

MikeT said:

I think what he is talking about is that the bolt with the safety wire is stationary, i.e. the nut on the bolt torqued and it does NOT rotate. When the arm moves there is relative motion between the actuator shaft and the bolt/arm of the flap mechanism. Eventually the safety wire will break.

Click to expand...

Yes, that was indeed my point. Thanks.

why

can the rod end unscrew when its bolted to the weldmount? if so could you just drill all the way threw the center and put in a cotter pin?

thats exactly what I did

Mike, it can unscrew because the tube the rodend screws into can turn when it is actuated. I did exactly what you mentioned. When I got everything set the way I needed it, I removed it and drill through the tube and rod end and installed a cotter pin. TaDa! I think it will hold better than the safety wire because the safety wire will fatigue some with each flap actuation in the opposite direction. I think the cotter pin will hold. I have considered a roll pin instead.

bird