Help needed to fine tune DCC Locos

[Earl Bathurst]

Hi

This question has probably been done to death but was wondering I have a few steam locos and they seem to run jerky at slow speeds. How can I rectify this problem? I never seem to have this problem with diesels maybe its the big fly wheel they have take this jerky running out of the equation so to speak.

 

Any help will be most welcome

 

Thanks

Scott

[34theletterbetweenB&D]

Take DCC out of the equation, test the chassis in question without a decoder on a simple DC supply (basic resistance controller or battery). If it doesn't run smoothly then sorting out mechanical deficiencies is the best place to start, rather than leave a decoder to (attempt to) mask them.

 

If the chassis is satisfactorily smooth on DC, but is degraded when the decoder is added, then it's a case of looking for what adjustment the decoder offers; and this is a variable feast with many different arrangements. BEMF sampling and response settings, drive frequency, motor types are all possible offerings.

[Earl Bathurst]

All locos run smooth on DC its as soon as I add the chip it becomes jerky as it runs at slow speeds.

 

Scott

[RFS]

Are they fitted with Bachmann decoders? In which case you may need to adjust the Back EMF CVs (54 and 55)  as suggested here:

 

http://www.Bachmann.co.uk/pdfs/decoder_settings.pdf

[Earl Bathurst]

Thanks, some are Bachmann and its those im having the trouble with. I have used mainly Gauge master in all my other locos, haven't noticed it with them yet as I aint given a loco with that decoder a good run.

 

Scott