I have a strange problem and I'm looking for help, please. I first noticed it after replacing the 3001 servos in my Bossanova with fast servos. The one aileron (ch 6) was 'jumpy' and slower than the other (ch 1). Dud servo, I though, so replaced it - and got the same result.

Changed to ch 5 and the same happens. By now I was using the Futaba 9CAP servo test facility that cycles all the channels and the servo would jump and not be entirely smooth across the full range.

I've since changed RX (from Futaba R147F to a Jeti Rex 5), RX crystal, channel (from 90 to 57) and TX (another 9CAP) and it happens on them all! I've also used a new model set in the 9CAP to eliminate mixes etc.

It only goes away when I use slower servos (e.g. 148, 3001 and JR 591). Looking very carefully at the other channels it seems to affect them as well - but less. None of these are digital servos, and I'm using PPM.

Is there anything I can do to stop/fix this, please?

Thanks.

Richard

I'm still trying to sort this and have uploaded a video showing the problem. I'm beginning to wonder if it might be the synthesised TX module in the 9CAP.

Can you help me sort this, please?

Thanks.

Richard
[link=http://www.rnorman.pwp.blueyonder.co.uk/Servos/JumpyServos.wmv] Video showing the problem[/link]

Maybe it is my old eyes but in the servo closeup it looks like the servo arm screw is not tight.

Thanks, eglitch, but that is an optical illusion - it is tight and the arm is not slipping. I've now tried putting two servos on the lead (using a Y-lead) and they both do it - even if they don't have arms on!?!

I had a suggestion that it might be a voltage problem so I've also tried supplying just the one servo from it's own battery (as you'd do for mechanical retract servo) and it does the same thing.

I'm still stumped and not getting much input from Futaba. I suspect something funny with the 9CAP (especially as two new 9CAPs do the same thing!) but I can't prove that without expensive test gear.

Richard

What kind of servos are the "fast" servos? If they're not Futaba, you may have a compatibility issue.

We were unable to d/l the video on our network.