Elevator Linkage/Surface at Null Issue

[Smacka]

Good Morning All:
Well, if adversity will help me learn, I will be a pro builder in no time at all...

Please see attached photos. I have the elevator servo linkage for my elevator adjusted as far in as I can get it and, as you can see, the flight surface is shifted off null.

Do I need to cut the linkage with a dremmel in order to allow for more inward adjustment? Is this a normal part of building aircraft, or am I just special?

The linkage came stock with the aircraft, however, the dual control horn is not. The ARF was drilled incorrectly for the 50cc hardware. I was supposed to use a metal clevis for the flight surface end of the linkage but I need to use the ball link for the dual control horn.

Thank you for your help!

[Hibrass]

Smacka,

I've been here before... Order a new turnbuckle or make a new link. If that is a Ti tunbuckle you could shorten it a bit but the right way to do it would be just to order a new one and pitch this one into the spare parts bucket...

Good Luck,

[Al Lewis]

Now you know why I make my linkage from scratch. LOL

[Smacka]

Thanks guys! It is some type of steel, and not Titanium. I think I will just order the Ti's...

Although, Al...I do like your carbon rod reinforced links. Perhaps you could email or PM me on how I could do this (?).

Thanks again!

[Tired Old Man]

The change in the elevator control horn likely changed the geometry from the elevator horn/shaft that was used when the manufacturer determined the length of the linkage rod. It definately needs to be shorter now. When we change things from what the manufacturer originally intended we need to recognize that the change in one item can effect a change in other items associated with our intended alteration.

The use of Pro Link style linkages is complately dependant on having servo and horn locations pre-planned around the use of specific length Pro Links. The lengths don't always work out. My experience is that frequently when the lengths do work they are still not long enough to leave enough of the threaded rod installed inside a clevis or ball link for safety. Take care and try to maintain at least 1/4" of threaded rod inside both ends of the clevises or ball links after the final adjustment has been made.

Making your own linkage out of threaded rod and some carbon or fiberglass tubing is extremely easy and very inexpensive. You can make all the linkage connections on a plane for about $15.00 and have material left over for the next plane. You might want to look into that for future use and reference.

[nickb]

Here's the easy fix- just turn the servo around 180* so that the output shaft is a little more forward.

[Tired Old Man]

That would be by far the easiest way if his new horn didn't move everything too far forward.

[Al Lewis]

	Quote: Originally Posted by Smacka
	Thanks guys! It is some type of steel, and not Titanium. I think I will just order the Ti's... Although, Al...I do like your carbon rod reinforced links. Perhaps you could email or PM me on how I could do this (?). Thanks again!

Like Pat said, just make the rods up to length with 4-40 all-thread, measure the distance between the swivels (with calipers) and cut the CF tube about .020" longer. Then when you put the tubing on over the all-thread the last turn of the swivel will lock it in place.

[Smacka]

	Quote: Originally Posted by Al Lewis
	Like Pat said, just make the rods up to length with 4-40 all-thread, measure the distance between the swivels (with calipers) and cut the CF tube about .020" longer. Then when you put the tubing on over the all-thread the last turn of the swivel will lock it in place.

Thank you Al & Pat (and everyone else who helped!). I appreciate your input. I really am having fun with this build, although my demeanor may not suggest it. One thing is for sure...I have been learning a ton from the folks on this site, and I want all to know I really appreciate the help!!!!

Onward & Upward...

[Smacka]

	Quote: Originally Posted by nickb
	Here's the easy fix- just turn the servo around 180* so that the output shaft is a little more forward.

I tried this based upon your suggestion but I had very little thread engagement left. Thank you for the suggestion, though. It was another avenue to exhaust in my troubleshooting effort.

I did order some 4-40 fully threaded rod. Additionally, I ordered CF tubing with .157" OD. The ID was stated to be .098". The OD of the 4-40 threaded rod was stated to be .093". I hope the clearance is enough to not have issues fabricating the new servo links.

One question...should I use any epoxy on the OD of the threaded rod prior to sliding the CF tubing into place?

This is going to be so cool when I fab my own links for the first time. Eventually, I want to purchase an AW 150cc Yak 54. I want to work out all of the kinks from my building technique well before undertaking that challenge.

[eagle1]

are you bottomed out on the threads? if so it looks like you could cut 1/8" or so off each end and bam you have your fix

[Spaz]

	Quote: Originally Posted by eagle1
	are you bottomed out on the threads? if so it looks like you could cut 1/8" or so off each end and bam you have your fix

yes just cut them already!! so easy (dremel cutoff wheel, 1/8" off each side shoud do it), and you won't have to ditch all the nice ends then. they are probably metric now and wont work with 4-40 and wont work on the end that is left handed threaded already

[Scrima]

	Quote: Originally Posted by Smacka
	I This is going to be so cool when I fab my own links for the first time. Eventually, I want to purchase an AW 150cc Yak 54. I want to work out all of the kinks from my building technique well before undertaking that challenge.

You'll be there in no time. I flew the 50cc Extra 260 for two seasons and am now building the 150cc Yak as my new IMAC machine.

Have fun! Just don't let anyone talk you into stick time on a plane bigger than yours. Made that mistake twice now...

[Smacka]

Well, I was able to install 5-inch titanium rods on the right and left elevator. They worked great! I know I said I was going to fab my own, and I now have the stuff to do just that BUT the 5-inch rods happened to be a perfect fit, so I used them.

I will definitely fab my own rods for the 150cc Yak 54...

Onward and Upward...