Control Linkages
 

I've used clevises at both the servo and the control surface ends of my control linkages. I've noticed that many people use wire with z bends at either or both ends.

How do you all decide what to use?

Captain Crunch

Control Linkages
 

It is a bit dangerous to use clevises at both ends of a push rod. If the clevis is not locked on to the threaded rod there is a danger of the pushrod turning during flight and unscrewing from one of the clevises.. In fact some contest safety checks will not pass a push rod with clevises both ends. With zee bends at both ends there is no rod length adjustment.

I use a clevis at the control end and a zee bend in the servo arm The rod cannot turn and I have adjustment.

Ed S

It Depends
 

Sometimes you end up with a threaded end, and sometimes you don't. When you don't, Z it. If you have a choice, always pick the one that gives the least play in the servo arm. By that I mean that sometimes the hole in the arm is reamed instead of precisely drilled and the Z is sloppy. Goldberg for one makes a nice keeper that snugs it up and keeps it from popping off, but get it as close as you can. Linkage slop is bad-bad-bad :mad:
On bigger models try to stay away from the nylon clevis and use a metal one with a keeper. Hayes makes a nice heavy duty nylon clevis with a steel pin that's OK too. After a few flights, check the linkages and arms for any vibration slop that may develope. OK, let's go flying...

Control Linkages
 

Captian,
Nice to see another Tulsan.
I'm just a beginner also.
Good Luck.
Scott

Control Linkages
 

Hey Cap'n:

I agree with Mr. Smith about clevises at both ends, but with one exception. When you have silver soldered one clevis end to the control rod, you will not have any problems.
Another method of attaching at one end is with a "U" bend instead of a "Z". It's easier to make.
Avoid using Easy type connectors at anything other than a throttle connection. At high loads, they have been known to part company with the item they were attached to, often to the destruction of the airplane.
Silversurfer

Control Linkages
 

For what it's worth... I always push a short (quarter inch or so) piece of fuel tubing over the clevis after it's attached. Of course you have to put the keeper on before you put the clevis on. This pretty well insures it won't come apart. From yet another Okie!

Control Linkages
 

I use to use 'Z' bends but found that were wearing a hole in the servo arm rather quickly. I now silver solder a metal clevise on the servo end and use a piece of fuel tubing also as a keeper. Always check your clevise's before a day of flying just to make sure they are holding up, saved more then one plane by doing this.

Control Linkages
 

Another thing we've noticed out here in the Arizona desert. UV and heat can make the nylon parts brittle. I've seen two planes go down when the center post on a clevis snapped off. I've replaced all external clevis' with metal ones (except the throttle for radio interference reasons).