I have a pair of 645s that were in another plane up until a month ago... never once caused an issue.

I have now moved them over to a new plane. I replaced the gears in both of them before moving them over. Now one of them jitters at fulll deflection on both high and low rates randomly. There is no pattern to it at all. The other one has done this as well but I have only seen it happen twice while the other side of has done it about 20 times in the testing I have been doing the last 2 days.

What causes this problem? I am using a heavy duty 24" extension on them and being used with a Futaba 138 PCM receiver on 6V. Same receiver that was in the other plane.

I have tried switching extensions with little or no help.

Had same problem with Futaba servos. Had dirty connectors. Cleaned and went away.

went and bought contact cleaner and still no luck

WOuld have been nice to see some input from hitec about what can cause this by now.. its only been 6 days. [:'(]

I noticed they first do this when the switch is turned on as well.

It's hard to say what your problem maybe. A faulty or dirty plug and or extension is a common denominator. That said its plausible the pot is dirty or damaged. I'd suggest sending your servos to Service for a free evaluation.

Hi Mike,

Well weather has been the pitts so I havent had much time to work on this problem. I just spent some time on it and I can duplicate the issue on any channel from the receiver.. just got a new receiver and that didnt solve the issue. I have tried 3 sets of extensions and contact cleaner.. even tried 6" extensions just to be sure I covered all bases.

It's rather odd... they were working fine till I changed the gears which I have done many times and never had a problem.

Looks like I will send them in on Monday and see what happens.