the weather,wiring,dcc and bad running?

[michaeld]

Dear all,

Just wondered if anyone has any experience of the following,

I've been building up in the loft an embryonic layout in 2mm FS ,at the moment some 10' of running,only three turnouts a crossover and siding made from copper clad sleepered components,the rest easitrak.Wired for DCC with adequate wiring and DCC.The locos run really well,zimo and CT Elektronik decoders. During the hot weather running has become very erratic,not all the locos all the time,each one differently at different times,but only in one direction strangely enough.

I've been scratching my head as how to or what to look for to solve this,should i re-wire,do copper clad points not like DCC? Does temperature effect DCC decoders at all?

 

Any thoughts would be gratefully received thanks in advance Michael

[Pete the Elaner]

If chips continue to work after a few minutes at high speed & therefore high temperature, I would have thought ambient temperature would not cause too much of a problem.

Is the problem consistent across the whole layout? If not, then maybe the rail has expanded a little creating a poor connection which is confusing the decoder?

[michaeld]

Thanks for the reply, yes certainly something is confusing the decoder,but its not all decoders all the time,one loco will behave strangely while others work well,and then the next session its a different one and so on...... Its not consistent across the layout either,its really odd! I've disconnected sections,changed the wiring to a stronger thicker type but to no avail,it is as though theres something fluctuating the signal to the decoder,but why not all the decoders all the time!?!?!? All very odd and frustrating......

[34theletterbetweenB&D]

Only in one direction. Some rectification making the track waveform assymetric? It is so easy to leave a wafer of copper behind on a copper clad sleeper edge in 4mm which can then move a little and cause a short, and it ain't going to be easier to avoid in 2mm. Then all it needs is a bit of expansion in the heat, and a little copper oxide on the tip of the wafer making contact.

 

To establish whether or not it is definitely in the layout, set up an independent length of plain track only, and connect just that to your DCC system and test the locos. Hopefully you are not in the beam path of some powerful microwave band emitter...

 

Be interested to hear what you finally diagnose.

[Edwin_m]

I was thinking of some kind of electrode/battery effect - have you used any differing materials anywhere? Though if this was a regular occurrence you'd think we'd have heard about it. Is asymmetric braking enabled on your decoders?

[Dagworth]

Just out of curiousity how long has the problem been occuring?

 

Andi

[michaeld]

OOH!

This is getting complicated, I dont think Im next to some radar instalation unless the neighbours are up to something!!!

I am a complete dunce as far as electronics go I have to say, its only been happening for a week or so,before everything was perfect,the locos have always run very well and have not had problems with them,i've tested on a plain un-connected piece of track and no problems at all. The loco decoder settings have not been changed to be honest havent got a clue what asymmetric braking is! and what is an electrode battery effect?

I have suspicions of something around the copperclad built points,but it is a mystery to me,but thanks for replying to this thread,its turning out to be really interesting

[Edwin_m]

Asymmetric braking is a system invented by Lenz where the if the DCC signal is a bit polarised, so that its negative voltage part is smaller than the positive part, then the train brakes to a stand. Not all decoder support it but Lenz and Zimo do. According to the Zimo manual it's controlled by CV27, but switched off by default and if you're not aware of this feature it is unlikely you will have enabled it.

 

The electrode suggestion comes from dim recollections of A-level chemistry where if two different metals are put in electrical contact there is a small voltage between them - in effect you have created a crude battery. It just struck me as possible that this might have happened with your track construction, though unless you have done very different things with the two rails then any effect existing would be cancelled out by the other rail doing the same thing.

 

These suggestions are definitely long shots. Amongst all the suggestions or warnings about DCC, either genuine or mythological, I've never heard anything like this.

[GasDad]

To eliminate possibilities - how good is your earth in the loft ?

 

In other words where or what are you plugging into ?

 

It shouldn't make a difference - but you never know.

[beast66606]

The best advice and the first to follow is to try the locos on a plain piece of track - not one of the layout lengths but a completely independent length on the work bench or the like - do the problem locos exhibit the same behaviour there ?

[Brian]

Hi michaeld

I assume you have cleaned the rails and the locos wheels?

These are often the main culprits where poor running is concerned.

Even new rail from the box needs a light clean before use to remove any tarnishing that naturally forms on the rails.

[mikeg]

Just a thought, have you put any ballast down as water,glue and copperclad could be the cause of the problem, as someone said it sounds as though you have a rectifier type of short in one of the breaks in the copperclad sleepers. I had this many years ago due to water laying on some points and forming a bridge that I could not find, had to take every thing up and relay to solve the problem.

 

regards

 

mike g

[buffalo]

There's more to DCC than decoders, wiring and trackwork Before getting too carried away looking for more obscure and esoteric sources of the problem in these, are you able to swap the controller/booster to ensure that this is not the cause?

 

Nick

[beast66606]

Before looking for any problems, check the locos are working correctly - if not then we have excluded the layout in one fell swoop (probably!)

[buffalo]

Before looking for any problems, check the locos are working correctly - if not then we have excluded the layout in one fell swoop (probably!)

 

Indeed, your previous suggestion of trying a separate piece of track is certainly the best initial test. Unfortunately, the original statement:

...not all the locos all the time,each one differently at different times,but only in one direction strangely enough.

makes it sound more like a layout, wiring or controller issue, so these may need to be isolated one by one.

 

Nick

[beast66606]

Indeed, your previous suggestion of trying a separate piece of track is certainly the best initial test. Unfortunately, the original statement:

 

makes it sound more like a layout, wiring or controller issue, so these may need to be isolated one by one.

 

Nick

 

Start with the simplest thing, if the locos behave on the test track then wait for them to misbehave and retest, if they then misbehave it's the locos, if they don't then move onto something more complicated to resolve.

[Lady_Ava_Hay]

Dear all,

Just wondered if anyone has any experience of the following,

I've been building up in the loft an embryonic layout in 2mm FS ,at the moment some 10' of running,only three turnouts a crossover and siding made from copper clad sleepered components,the rest easitrak.Wired for DCC with adequate wiring and DCC.The locos run really well,zimo and CT Elektronik decoders. During the hot weather running has become very erratic,not all the locos all the time,each one differently at different times,but only in one direction strangely enough.

I've been scratching my head as how to or what to look for to solve this,should i re-wire,do copper clad points not like DCC? Does temperature effect DCC decoders at all?

 

Any thoughts would be gratefully received thanks in advance Michael

 

One last question. What make/model of command station?