Adjustable Controls?

[Chris Fretz]

Can anyone explain to me what good it is to have adjustable pushrod in between the flap horn and elevator horn that when you turn the pushrod one side will shorten where the other side lengthens? Or vise versa. In other words it will never change the length!

[Alan Resinger]

Chris,
Most advanced level flyers use adjustable controls.  Adjusting the pushrod length is very common.  Using carbon fiber pushrods, the elevator pushrod has threaded inserts glued into the ends.  One has right handed threads while the opposite end uses left had threads.  These thread into ball links that are attached to the flap  and elevator horns.  A half turn of the pushrod equals either one thread length of change either longer or shorter depending on the direction of the turn.
Alan Resinger

[Chris Fretz]

Chris,
Most advanced level flyers use adjustable controls.  Adjusting the pushrod length is very common.  Using carbon fiber pushrods, the elevator pushrod has threaded inserts glued into the ends.  One has right handed threads while the opposite end uses left had threads.  These thread into ball links that are attached to the flap  and elevator horns.  A half turn of the pushrod equals either one thread length of change either longer or shorter depending on the direction of the turn.
Alan Resinger

I understand that,  I got these Tom Morris controls an both ends have right handed threads sooooooooo totally useless!  I won't be able to adjust these things once I put it together. Ugh

[Tim Wescott]

I understand that,  I got these Tom Morris controls an both ends have right handed threads sooooooooo totally useless!  I won't be able to adjust these things once I put it together. Ugh

Take the ball link off the elevator, give it a turn, reattach...

Who makes left-handed screws for ball links?

[Chris Fretz]

Take the ball link off the elevator, give it a turn, reattach...

Who makes left-handed screws for ball links?

So this is the way it's supposed to be? How am I going to do that once this thing is put together, besides cutting a big hole in this ARF Nobler?

[Mark Scarborough]

So this is the way it's supposed to be? How am I going to do that once this thing is put together, besides cutting a big hole in this ARF Nobler?

most contemporary PA airplanes in fact have a hatch in the tail for access. so yes you will need to cut an access hatch, but be forewarned, you may also want a small port on the opposite side of the hatch for access to the slider nut on the elevator horn ( assuming you have a slider horn?)

some pushrods have left and right threads like Alan says, others simply remove one end, generally the elevator, adjust the ball link and then reattach

Tim, Tom Morris makes right and left inserts, Ball links are Asexual , they have no threads out of the package, so you can thread them either way,,   

[john e. holliday]

If you got the stuff from Tom, he has the correct ends to make the push rod adjustable by turning it.  I have a set hanging in the shop waiting for a plane.  Like said one is left hand and other right hand.  If you check, most ball links the threads are cut when you screw the connector on.  

Mark beat me to it.  But i'll post anyway.

[Chris Fretz]

So did I get hosed on the left handed thread, or do you guys specify you want one left handed an one right handed when ordering from Tom??

[john e. holliday]

You need to specify.  I don't think he reads minds yet>   OOPs sarcastic me again sorry.

[Brian Hampton]

I use a 4-40 turnbuckle which I think are for RC car steering rods. The ball joints are set up for 4-40 also but being plastic the LH thread on the turnbuckle cuts its own thread as you screw it in. I cut the length of the turnbuckle down so there's only a few threads (about 1/8" either side) showing for adjustment.

[Chris Fretz]

You need to specify.  I don't think he reads minds yet>   OOPs sarcastic me again sorry.

I always learn the hard way.

[Motorman]

Dubro makes the ball link ends and they are not threaded so you can still use your lefty rod end if you just grind a little taper on the end and screw it in there with force like a roll form tap. I'm sure Tom Morris would tap out a lefty for you if you call. I didn't specify and got 4 that were taped right hand ymmv.

The Morris push rods are sized for 4-40 all thread, are made from polyester resin and split pretty easy when drilling. If you have the Titanium rod ends I'd suggest getting larger diameter carbon rods so you don't have to drill. You can carefully drill without splitting but you have thinner wall. My comfort level goes up allot with the larger push rod for Ti ends.  

Plastic ball links cold flow to lock the threads to some extent but, if you have one left and one right I'd use at least one jam nut so it doesn't turn from vibration for unwanted adjustment. I take a nyloc nut and run it on the threads to thread the nylon then take it off and turn it around then put the ball link on and tighten the nut down on it at the bellcrank end and make all my adjustments at the tail end. Of course this defeats the purpose of left and right ends so, if you want to double your adjustment range put the jam nut at the tail so you can loosen it through the adjustment hatch and just spin the push rod without removing the rod from the elevator horn.

When judging the length be sure to leave some adjustment range in both directions with everything in neutral, lol don't ask me how I know.

Hope that helps,
MM