turnbuckle pushrodsl

The pre-built pushrods in the UHP Impact are by Tom Morris and beautiful to behold. So naturally I've used heat to remove the threaded insert on one end and used JB weld to install a Left handed threaded insert in its place. Now the pushrod is a turnbuckle and turning it either way will adjust the controls. The only LH threaded insert I could get is actually a 4-40 turnbuckle itself and didn't make a tight fit inside the rod, so the JB weld has to fill in the gap and hold the whole thing together. I've not installed it in the Impact yet so there is still time to go another route. Any ideas on how long this "loose" insert will stay JB welded in place? thanks,

Dale,

Tom has left handed threaded inserts that will fit - give him a call!

It is not just "fit", it is "break". I would not use that 4-40 insert. On another thread we have the story of a flyer who lost his ship due to a failed 4-40 clevis. And why do you need a turnbucke pushrod anyway? With that you need two hatches, one at the front, one at the rear to get at it.

That adjustment is there for "if needed." You should build the plane straight and true so that it is not needed. But you know Murphy. He has enacted more laws than the US Congress. And his most famous is, "If it can, it will." So, if you don't put in that adjustment, you will need it. If you do put it in, you won't (or you hope you wont.) But if you do need it, it should be a one time adjustment. This isn't something you do every day, every week, every month.

Matt put an adjustable pushrod in his latest ship with a hatch under the pipe where it can't be seen. No, it is not convenient. But it is available, if needed. And if needed, you adjust it once...hopefully...done for the next 2000 flights.

Thanks guys- calling Tom and putting it under the pipe.I wasn't really at all happy with the set-up and this forum gave me time to get some ideas and just stop and think for a while- a great service! best regards,

Thanks for the idea on accessing the pushrod through the pipe cavity. That's excellent!

Thanks, Dee

>That adjustment is there for "if needed." You should build
>the plane straight and true so that it is not needed.

It's of value to be able to change the flap/elevator neutral even if you build the airplane straight. Adjustment ability is there to enhance trim, not only to correct for flaws.

> It's of value to be able to change the flap/elevator
>neutral even if you build the airplane straight. Adjustment
>ability is there to enhance trim, not only to correct for
>flaws.
>
> Brett

I agree. Sometimes it is hard to measure that last 1/8 of a degree. We can "eyeball", but...

Also, with the RH-LH combo, access to one end only is required since you only need a locknut at one end. Loosen the nut, rotate the center section, relock the nut.

It makes no defference to the failure potential whether the rod end is RH or LH threads.

Also, just for reference points, a natiaonally known flyer in this area has lost two planes in the last three years due to solid music wire elevator push rods failing---away from any bending or other stress riser--looks to be simple vibration induced breakage. Probably related also to poor material--but how would you know ahead of time?

Same chances with threaded rod or formed rod ends.

FWIW