ESU V4 juddering at slower speeds - either direction

[RhBBob]

Have fitted a V4 into a double-bogie electric loco but, despite having run the CV 54 = 0 several times, slow speed performance is a series of judders !  Runs okay once the speed is racked up.

 

Out of the loco and under analogue control, the bogie runs okay. It is a standard gear train as I have given up on the Maxon belt drive after the motor screws wore out trying to tighten the beast.......

 

CV 54 has automatically set to '7' after the high-speed-run, so have I missed something in the remaining CVs?

[MiDAS]

 Altering CV52 can sometimes assist with smooth running at very low speed its worth a try.

Terry

[Guest taylorc]

Have fitted a V4 into a double-bogie electric loco but, despite having run the CV 54 = 0 several times, slow speed performance is a series of judders !  Runs okay once the speed is racked up.

 

Out of the loco and under analogue control, the bogie runs okay. It is a standard gear train as I have given up on the Maxon belt drive after the motor screws wore out trying to tighten the beast.......

 

CV 54 has automatically set to '7' after the high-speed-run, so have I missed something in the remaining CVs?

 

Had exactly the same problem with a Bachmann class 66 with a Zimo sound decoder ( I know its not a ESU V4, but this may be relevant). I removed the capacitors across the motor (I think there were 3) and the problem disappeared.

Worth a try.

 

Colin

[RhBBob]

Thanks to Colin and Terry for your input !

 

I played around with the CVs from 50 to 54 but no joy; no capacitors fitted to the motor, which is an Alpin Line version of the Buhler 12v motor that Fama/Utz/Roco Alpine Line previously used.

 

As always, quite by chance, I decided to adjust the speed table so that the start voltage went from 3v to 6v.  I programme decoders on a Sprog2 which means shifting the speed table to the left.

 

And the result was a delightful slow start-up speed and smooth transition to running speed.

 

Happiness has returned