Model Railway Forum

I think this is the right place for this question.

I've posted before about keeping my DCC layout (stil building and developing) running smoothly. HAd some juddering and some places where locos just stop when slow running.

Plenty of dropper wires so supply is not the issue.

I've now got IPA (not the beer!) for cleaning and use a track rubber followed by IPA on a clean cloth. I've also cleaned loco wheels. I have laid some ballast recently but have carefully cleaned those areas so there shouldn't be PVA residue. Yet still some places where it stops and a bit juddery.

I am thinking maybe one issue is it is in the loft - only space I have for a layout. Also I am still working on it which may be contributing negatively to cleanliness issues.

Wagons and coaches have hardly been used so that's ot the issue but I will clean them all and check they are all metal wheels - as previously advised.

At exhibtions I do notive layout controllers quite often ave to intervene to get things rolling so maybe this is normal - I have modelled for over thirty years.

I have a single track loop to simulate a small WR branch line with a terminus station and marshalling/goods yard on one side.

Despite all of these thoughts, am I missing something please?

Apologies - just realised I could have added this to my earlier post.

If the rails are spotlessly clean and the locos pick up wheel rims and any rear of wheel wiper contacts spotlessly clean then the problem is either track that is not flat or poor metal rail joiners failing to pass both power and data rail to rail.

Thanks Brian. The track is nicely flat and I've carefully checked the conductive rail joiners - I joined the rails extremely carefully.

On further reflection, what I have noticed is it only happens at slow speeds.

Also, is it sufficient to clean just the top of the rails?

Normally only the top of the rail is cleaned. Except points where the stock rails inner face and switch rails outer face should also be carefully be kept clean when relying on the point blades to make contact

On DCC you have full rail volts (Typically 14 to 15 volts) permanently on the rails. This regardless of speed setting is always there.
Depending on your DCC system I would start now to look at CV settings.
Initially carry out a decoder reset. Often this is CV8 entering a value of 8 causes the reset. Address number will also become 3. Test loco if still poor then check and adjust CV2 Start voltage. Using ideally speed step 128 set CV2 value so as the loco just discernibly moves at step 1. Test loco if still shows hesitancy look at CV54 and CV55 Setting CV54 to a low value number of say 10 and CV55 to a value of 50. Finally try turning off the decoders Backemf feature via CV10

Dont forget a decoder reset CV8/8 will always revert t to manufacturers default settings. Check decoder manual to ensure CV8 / 8 is the reset.

What decoder is it and what DCC system is being used?

I am using a Gaugemaster Prodigy Express - I will only have 3 locos.

For testing purposes a Hatton's (Dave Jones) 14xx using a youchoos sound chip fitted by John at youchoos. Also have a Hornby Railroad 440 County of Devon also with a youchoos sound chip.

Mostly even slow running is ok just still some spots where it stops - a small push and all comes back live again including sound. Also, no polarity issues on live frogs - all well there.

The only serious reasons a loco stops are loss of data or loss of rail voltage.
Causes can be many things including wheel wipers not remaining in continual contact with the rear of the wheel when the wheel moves across the loco slightly and all the ones Ive already spoken about.

BTW you're not using Hornby plug-in power clips or their power track sections are you?

Does the loco always stop in the same place?

Definitely appears to be uneven track. Is it laid straight on the board and firmly fixed down?

No clips. BUS wires to terminal blocks - radial system. All dropper wires soldered to side of track and tested using MM for continuity. Also sections of track tested for continuity back to the power supply from which all the BUS wires run - continuity all good.

My instinct says keep cleaning as it's a new (and still being built) layout but never built DCC layout before.

All track carefully laid on 1/16 inch cork mat and pinned.