Motor/DCC combinations

oldravendale

Western Thunderer
There's a problem raised it's head at club and I'm wondering whether any member of this erudite group can help resolve it.

One of our members has a Skytrex Class 40 which runs fine on analogue. The DCC controller in common use at club is the NCE Powercab and the loco is equipped with a Loksound V4 decoder. When running in DCC mode the loco will not run at normal speed but only crawls around the track. We've tried playing with CVs but can't increase the maximum speed.

Does anyone have any idea why this may have occurred or how to solve it?

Brian
 

richard carr

Western Thunderer
Brian

There could be a hundred different reasons which I know isn't much help for this, but here are two that would be my starting point. What your club really needs though is a Lok programmer so you can easily see how your decoder is set up and make the necessary changes to sort these situations out.

First, what is CV 5 set to, this is the maximum loco speed is should be a high number near to 64 if its set low then the loco will never go fast.

Then try CV 53 the emf reference voltage, it again defines the maximum motor speed try a value of 57 which equates to 14.4 volts

If neither of those help then to offer any more help we need to know a lot of cv values which is where a lok programmer or a SPROG really make life easy.

Richard
 

Steph Dale

Western Thunderer
Dad/Brian,

Have you tried re-setting the decoder? There's just a chance that the decoder has been used for testing and may need to be reset to factory defaults.

Also, does the loco with it's decoder fitted run okay on analogue or not?

Steph
 

oldravendale

Western Thunderer
Brian

There could be a hundred different reasons which I know isn't much help for this, but here are two that would be my starting point. What your club really needs though is a Lok programmer so you can easily see how your decoder is set up and make the necessary changes to sort these situations out.

First, what is CV 5 set to, this is the maximum loco speed is should be a high number near to 64 if its set low then the loco will never go fast.

Then try CV 53 the emf reference voltage, it again defines the maximum motor speed try a value of 57 which equates to 14.4 volts

If neither of those help then to offer any more help we need to know a lot of cv values which is where a lok programmer or a SPROG really make life easy.

Richard

Thanks Richard. We'll have a look at these possibilities on Thursday evening. We don't have a Sprog or Lokprogrammer at the moment but looks as though a purchase may be in the offing.....

Dad/Brian,

Have you tried re-setting the decoder? There's just a chance that the decoder has been used for testing and may need to be reset to factory defaults.

Also, does the loco with it's decoder fitted run okay on analogue or not? Steph

Yes, resetting the decoder tried. It was also tried in a class 25 - Bachman I think - and worked fine.

I can't remember whether we tried running the loco on analogue with the decoder fitted. I'll have to check on that one too.

Thanks for the thoughts. Moves us on a bit.

I'll report back shortly (stop calling me shorty.....)

Brian
 

JimG

Western Thunderer
Thanks Richard. We'll have a look at these possibilities on Thursday evening. We don't have a Sprog or Lokprogrammer at the moment but looks as though a purchase may be in the offing.....

Brian,

Do you have a USB interface for your PowerCab? If so, hook up to your computer and install JMRI DecoderPro software and you have the (a bit bigger :) ) equivalent of Sprog. I use this setup and it works very well and allows easy investigation and setting of CVs. There can be the occasional problem of getting the software to see the USB channel of the interface but that can usually be sorted out quite quickly. The Yahoo group for NCE are very helpful if you hit problems.

Jim.
 

TheSnapper

Western Thunderer
Brian

I've seen this before.

If its the small "00" version of the Loksound V4, its possible that it is not up to the job.

Can you try a larger decoder ie a V4 XL (or better still, a Zimo 695 - (sorry))?

Tim
 

oldravendale

Western Thunderer
Brian,

Do you have a USB interface for your PowerCab? If so, hook up to your computer and install JMRI DecoderPro software and you have the (a bit bigger :) ) equivalent of Sprog. I use this setup and it works very well and allows easy investigation and setting of CVs. There can be the occasional problem of getting the software to see the USB channel of the interface but that can usually be sorted out quite quickly. The Yahoo group for NCE are very helpful if you hit problems.

Jim.

Thanks for the thought, Jim, but no USB interface!

However, on reviewing the Whitchcraft thread I not some discussion about motor power potentially being influenced by the motors being in series or parallel. That's one I'll follow up, although I suspect that the issue is probably not associated with this as installing the chip in another loco it worked fine. Anyway, I'll check again tomorrow.

I appreciate all the help here.

Brian
 

oldravendale

Western Thunderer
Brian

I've seen this before.

If its the small "00" version of the Loksound V4, its possible that it is not up to the job.

Can you try a larger decoder ie a V4 XL (or better still, a Zimo 695 - (sorry))?

Tim

Hi Tim.

Yes, it is the OO version decoder. In my ignorance I assumed (assumption being the mother of all f cock
mess ups:)) that a decoder which was not up to the power of the motor/s would burn out. In fact, however, one thing we've not checked is the stall current, so that now goes on the list.

We have no XL decoders on any locos - at least so far although if decoders are to be fitted to any of the Heljan locos in the future I believe the XL decoder will be a requirement.

All these comments prompt other thoughts in this combination of synapses which I choose to call a mind, so please keep 'em coming! Unlike the lad I'm very far from understanding electrickery and even further away from understanding electronickery so it's impossible to offend by suggesting the most basic of possible causes.

(By way of explanation of my involvement in this stuff when I understand so little, it was I who introduced the club to DCC and sound, having with Steph's help successfully fitted decoders in several locos, which Steph then tuned for me and I ran on the branch of the club layout. I'm therefore regarded as A MAN WHO MUST BE CONSULTED. Up until this time most of the club locos and controllers had clockwork motors or valves in them...... And it wasn't for radio control. I jest, of course.)

Brian
 

Steph Dale

Western Thunderer
Nothing wrong with valves Dad; although quite how you'd fit an ECC83 and power supply in even an 0-gauge loco is a bit beyond me.

I hadn't thought about an under-size decoder, as is not something I've experienced, but the symptoms are consistent. The decoder would go into a self protect mode which would limit the current delivery; reducing the amount of power to kick the motor. Hence the motor wouldn't have the torque to speed up, even when given increased voltage.

Steph
 

oldravendale

Western Thunderer
Nothing wrong with valves Dad; although quite how you'd fit an ECC83 and power supply in even an 0-gauge loco is a bit beyond me.

I hadn't thought about an under-size decoder, as is not something I've experienced, but the symptoms are consistent. The decoder would go into a self protect mode which would limit the current delivery; reducing the amount of power to kick the motor. Hence the motor wouldn't have the torque to speed up, even when given increased voltage.

Steph

Bet that's what it is, then! Well done Tim for suggesting something I thought was unlikely..

I'll have a bit more of a poke around tomorrow and report back.

Brian
 

oldravendale

Western Thunderer
Actually, Simon, no! The owner of the loco (in his wisdom) decided to remotor the loco, and then the decoder worked ok. I suspect, therefore, that it was an undersize decoder in the first place but can't now prove it.

Frustrating!!

Brian
 
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