Hi Folks,
Last night I decided to remove the plastic clevis that attached to the throttle arm, cut the control rod just below the threads and use a Z-bend tool to re-attach the rod to the throttle arm (the bottom of the clevis was hitting against the top of the forward bolt holding down the engine strap). Unfortunately, while I was using the Z-tool, when I'd just about get a 90 degree bend in the rod, BAM!!, the rod would break (sorry about the Emeril reference). That led me to believe that the rod material that came with my Tower Trainer pretty much s*cks.
Anyway, I'd like to purchase some rods, made out of decent metal, to have on hand for future use. Can you folks recommend any rods, and their sizes, that are used in ARF's? I'm assuming that surface rods are the same size (thickness) as throttle rods. Thanks.

You can run over to your LHS and pick up some 2-56 sized push rods. These would be fine for throttle control. There are other sizes available in both threaded and non threaded ends. Some people will use very light rods on the throttle, but I generaly use 2-56 size. On a 60 size plane I will usually use 4-40 size for the other controls for a little more security.

2-56 threaded rods will do fine. You can get them in various lengths.

One thing to look out for . . 2-56 and the metric 'equivalent' look very similar, and the clevises LOOK as if they are interchangeable. They are not! You run the risk of threading the metric clevis onto the 2-56 rod (or vice versa) and finding out later that the threads aren't the same and the clevis slips. Not a good thing when flying!

-David C.

I had the same problem on my Alpha trainer, clevis hitting engine bolts. I changed the linkage to a "ball and socket" on the throttle arm. It is not the snap on type, but the spring type that you have to hold back, slide on the ball, and release it and it locks. Works good and brings the pusrod out enough to clear the bolts. I think I spent 2.50 on the kit. Also got rid of the binding problem I had. The T arm was not in line with the pushrod exit at the firewall. Lined it up perfectly. I am planning on changing it to a flexible cable though in the near future!!

What is the thickness of the 2-56 and 4-40 control rods?

I've had good luck with Sullivan 4-40 control rods. Not too expensive either, about 4.50

Just a thought...

If you have a torch (or even a gas stove) you could try heating up the rod until it is RED hot. Let it stay red for a few seconds, then, slowly remove the heat, and let it cool down without quenching it.

That just might anneal (soften) the metal and allow you to bend it without it snapping.