Model Railway Forum

I have recently changed several of my loco's to DCC and now have a problem with three of them. They ran fine when they were analogue, now they go for about 6 - 12 inches then stop. After a few seconds they slowly start moving but after another 6 - 12 inches they come to a stop again. They all have the same 8 pin decoder and others that have the same decoder run smoothly. They are all tested on the same length of track which is clean and has a constant power supply. Any suggestions?

What brand of decoder?
have you read the decoder manual & attempted to sort out CVs that affect BEMF, etc?

I would first start with the track - you say it is clean but have you hovered up any crud after using a track rubber (small bits can still be on the rails) and wiped the rails with a cloth and IPA?

Secondly clean the loco wheels - both the rims and the backs where the pickups make contact. A fiberglass pencil and IPA will do the job.

Thirdly is the track absolutely, perfectly flat and level?

Good advice from Steve. Everything does need to be clean and kept that way. Even a small section of track will, I've found, bring locos to a halt. Once I have cleaned, even my Peckett has no running problems - and I use (sorry to the purists!), insulfrog points with DCC.

Try and dissable the inertia and the back emf settings on the decoder. You may have to set them to the minimum figure. I had the same and it was puzzling, and I assumed that I had a faulty decoder. However, after reading in one of these forums about it and how to remedy it, I was then able to sort it out. And it works!

Thanks for the replies. I've now cleaned all the locos wheels and put out a brand new yard length of track on a flat surface and still experience problems. I am using Hattons decoders. The instructions that come with them are very minimal. I'll now have a go at altering the emf settins but I'd better ask someone at my club re these as I'm unsure as to how to do it.

Some DCC controllers are easier to alter settings then others and also some can access areas that other's can't. With my DCC system, it can do most things though compared to today my functions are somewhat limited as I don't have 30+. When my system was made it was rare to need to access any more then three. I think mine does about 14.. Maybe more. Can't remember.
But I can do things that others can't like run early DCC locos that runnon 27 speed steps etc. Actually, a few features that seem to have been dropped today. However, all that matters is that one can getmones trains to work properly!

A visit to your club with a knowledgeable person should be able to try things to see if they can bring things to life.

I hope all is sorted for you.

P.S. I am no expert. Every time I get my DCC system out I have pages of instructions out at the same time. Shows that I have not used it often.