Sticky Servo

[malc1]

Hi all

I `ve got a JR 8455 Metal gear servo fitted to the throttle of my T Rex 600N and as of Saturday I noticed that it has starting sticking randomly at different positions - nearly caught me out a couple of time as well!

When stuck just touching the servo wheel will release it but moving the stick rapidly up and down will not.
If you wait a while it does sometimes release it self and move to the required position.

It does not make any buzzing or any other noise when stuck.

I have unhooked the linkage to the throttle and by passed the Mulitgov Governer - it still does it.

Obviously not the best situation so has any one any ideas?

Malcolm

[oteskate]

Malcolm.. I would start by opening it up and seeing if there's any small issues internally. I can't say I've ever had a servo act like that, but that's where I would start. I would also carefully check all the wiring and make sure that everything is in tact and not frayed or broken in any way. With you mentioning how when you touch the servo arm it helps it along... kinda sounds like a gear or potentiometer issue somehow maybe.

If everything inside looks good, then I would just replace it. Better to replace and have peace of mind than to wonder and hope that it works well.

[mac_man]

Its the motor. I have seen this on numerous occasions and it's invariably the motor. Is it mounted correctly ? Not touching the frame at all anywhere ? What voltage are you using, is there any evidence of fuel ingress ?

Send it back to MacG's for repair.

[malc1]

The servo is correctly mounted using the recommended nitro heli method and a standard Align regulator is being used.

Is this servo a 4.8v only?

Anyway spoke to Terry at Macgregors today and he thinks its the motor that is to fault.It seems that there are 5 windings involved and one may have developed a problem.

Its been packed up and sent back for a replacement - can`t really take any chances.
Hope its back before the weekend.

[malc1]

All sorted.
A new unit received, fitted to the heli and ready to go.
Thanks Macgregors.