12x Turn On Question
 

Can anyone tell me how to avoid the following ?
I power up my 12X Tx first (of course), then power on the R1221X receiver in my model. Upon the initial turn on, the servos "twitch" for lack of a better word, just for that split second. Not a problem at all, except that when they do, it moves my UP3 valve just enough for it to try and cycle the gear. A minor nusiance I know, but if I forget to support the model I am afraid I might get a gear collapse and damage my gear doors (and ruin my day ). Is this just something I have to live with or is there a fix ?
Thanks-Mike O.

Put a little slop in the servo arm to valve pushrod.

I would try rebinding it if you haven't done so already. If it is 2.4 of course.

You can try re binding with the gear in the down position. But also what servo are you using?

Dave

Do you have an analog servo on the gear valve? If so, switch it out for a digital and you will not have the issue.

Mike

Dave/Mike : It's an old analog JR -I will switch it out and try it again. Thanks guys-

Any servo that's not digital on that radio setup, will twitch as you describe. I call it a partial deflection and Hitecs are the worst. Horizon admitted there was a problem but neither JR or Horizon ever offered a fix.

That will fix it for you :)

It's not just JR that does this with analogue servo's, I've experienced it with other brands as well

Mike

Rebind with Gear switch in the "Down Gear Position", Brakes Off, Throttle Idle and Idle Trim, Flaps up. Make sure you set your ECU back up again.

It's got nothing to do with binding unless say the gear is retracting when the model is turned on and before it links with the tx. In this case since the tx can operate rx's with either 1024 or 2048 resolution, there's a pulse sent out by the rx to the servos in the 700 ms range to help setup which resolution. Analog servos don't like that pulse. If operating an rx that's only 1024 it doesn't happen.

I had the same problem yesterday at the field. Have a 12x, would power up and do the same thing. PITA as the gear would start to cycle then rebound back...I Re-binded and it fixed the problem

Read OP original post of UP3 gear valve moving. Rebinding NEVER hurts!!!!

Yes, you should read the OP's post;
" Not a problem at all, except that when they do, it moves my UP3 valve just enough for it to try and cycle the gear."
If it was a case of the gear switch being in the wrong position when bound to the tx, the gear would retract completely, not just move the valve "just enough".

All,
I experienced similar problems with my JR 9303 in both the Gripen and Boomerang. Tried rebinding, digital servos, etc. without result. The final step was a Gear Saver, EDR-126, from Andy Low at electrodynam.com. Problem solved and I'm a happy camper.
Rgds,
Art

So, Mike, it has been several days. Have you resolve your retract issue? If so, how was it resolved for others to learn? Thanks!

I have been so busy at work, I have not had the chance to try a digital servo instead of the analog. I will report back ASAP. Thanks to everybody for all the input !