Sorry if this has been covered before/elsewhere, but what does it mean if my drum rocks back and forth a few mm without me touching the control stick?

What might have caused this?

Many thanks

David

If you have an RMG winch, check your manual for Deadband

John

Input Deadband 

Input deadband is the amount dithering in the Rx signal that a servo can tolerate without responding to by constantly jittering. This is adjustable from 0.8 to 10 microseconds. Deadband adjustment allows the optimisation of TX fine trim control. The default setting is 5 microseconds.
 

It’s just a standard DF95 digital servo winch. The problem only arose once I discovered some water ingress. Could that have caused the servo to misbehave? Permanently?

Thank you, John, for your input but it was a bit too technical for an amateur like me. 

David 

Deffo water.  I sail on a brackish lake and water in the boat is a definite "standby to replace" the servos or receiver...

Ok, thanks I will try a spare receiver that I have first. They’re cheaper!

I was in touch with rcyachts today (about the new rudder arm). He pointed me straight away to the V3 95 upgrades. Which also include an updated winch: "a more consistent performance and end point accuracy". Not sure that would explain a twitch if your stick is staying in same place, but I reckon any wobble or grime - which could include lurking water - could cause that. 

I notice mine doesn't always sheet out-in-out-in to the same place. (Mine isn't v3)

DF's are very decent boats for the price, and great racing. But for the price they're not equipped to 'RMG' level....

 

 

8 hours ago, David Norris said:

Ok, thanks I will try a spare receiver that I have first. They’re cheaper!

I wouldn't expect a new receiver to make a difference- it's a very digital/logic-level beast, not a lot it can do to behave slightly differently. The signal to servo is the timings of pulses, not absolute voltage levels.

Check all rcvr connections are clean n dry tho!

Edited May 12, 2025May 12 by Colin Helliwell

It does seem that the latest DF digital servos are prone to this problem and I suspect that it is a fundamental design issue.  It is probably still worth trying a few things to confirm.

Try the winch in a different channel on your Rx

Try your winch on a different Rx

Try a different Tx

Try a different battery and leads

I suspect that none of these will make any difference.  If so then there is not a lot you can do

My guess (and it is only a guess) is that the control algorithm has been too highly tuned for maximum performance (speed / position accuracy).  Whilst it works well when the winch is new, if the electrical / mechanical properties change over time then control accuracy can degrade.

I wonder if a new version will be released or perhaps even a software upgrade will become available.