# Locomotive creep



## Gwpapa (Dec 6, 2014)

I have several locomotives that I have converted to DCC. One of them always wants to creep forward after I close down the throttle. Is there something in the CV values I need to look at? I thought I had read this question before but a search didn't help. This is not just deceleration it just wants creep forward like the speed setting is about 01.


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## DonR (Oct 18, 2012)

Check the first thread in this DCC forum, CV value chart.

See if it gives you the settings to control your loco creep.

Otherwise, stay tuned. Some of our members are very
informed about the correct settings of DCC decoder CVs.

Don


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## Gwpapa (Dec 6, 2014)

I didn't see anything in the CV chart that looked to be the answer. I could have looked over it because I don't always understand that things. I am new to the DCC stuff and just tring to see what all those values mean.


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## Brakeman Jake (Mar 8, 2009)

Can you read/write CVs?What's the decoder brand/model?


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## Gwpapa (Dec 6, 2014)

I can write CVs fine. It looks like I need a program track to read the CV values. I don't have a dedicated program track yet. The decoder is a digital w/sound etc. and I have a NCE power cab controller.


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## Gwpapa (Dec 6, 2014)

This was the only locomotive I had that was DCC ready so I just pluged the decoder in. The decoder is a SDXH166D.


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## Brakeman Jake (Mar 8, 2009)

Hard to tell without reading CVs.I'd try disabling DC operation with CV29=34,just a guess.It can't hurt the decoder.


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## Gwpapa (Dec 6, 2014)

Thanks I will try that.


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## MrMoose (Dec 22, 2014)

What kind of Locomotive is it...diesel or Steam and what model is it?

If your comfortable with changing cv values then try these for Diesel.

CV 29=50
CV 25=2
CV 66&95=70
CV 2=5
CV 212=100
CV 209=90
CV 3&4=125 
CV 10=40


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## Gwpapa (Dec 6, 2014)

Sorry should have said before that it is steam. I don't mind changing the CVs if I know which ones to modify.


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## Brakeman Jake (Mar 8, 2009)

An important question wasn't asked...does the creeping only last a few seconds or is the loco keeping going as long as it is on the track after throttling down?Does the loco start moving right away when trackpower is applied or only after throttling back?

If it starts moving upon powering the track and keeps going indefinitely,then I suspect the decoder is allowing DC to reach the motor at throttle 0 setting.Possibly a defective decoder but may be disabling DC (CV29=34) will cure the problem.

If it only keeps going for a little while after throttling down,then deceleration momentum may be set very high.If so,setting CV4=0 should erase the problem.It is the unlikely problem though with the info so far.


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## MrMoose (Dec 22, 2014)

Gwpapa said:


> Sorry should have said before that it is steam. I don't mind changing the CVs if I know which ones to modify.


I have used these setting on my steam loco and they worked pretty good for that also.


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## Gwpapa (Dec 6, 2014)

It only moves about 10-12 inches after the throttle is brought down to zero. I don't remember it ever moving upon powering up the track. I was using the factory default on most all the CV values except for a few I changed mostly related to the sound functions. From the responses it does sound like it may be the momentum factor. I will try to change that tonight. Thanks!


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## Cycleops (Dec 6, 2014)

If all else fails read the manual that came with it. If it's a Tsunami then then the sparse instructions that come with them won't help. Go to their website and download the relevant one. Don't forget your Powercab has a momentum key too but the value doesn't show on the display so just put in a zero to make sure.


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## Gwpapa (Dec 6, 2014)

I did read the entire manual that came with both the decoder and the NCE Power cab. That doesn't mean I know everything about them but I did read them.


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## D&J Railroad (Oct 4, 2013)

MrMoose said:


> What kind of Locomotive is it...diesel or Steam and what model is it?
> 
> If your comfortable with changing cv values then try these for Diesel.
> 
> ...


What do these change? I noted CV 3 and CV 4 are set to 125. That seems to be awful high for start and stop momentum.


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## DavefromMD (Jul 25, 2013)

If you have and NCE Power cab, you can go into program mode. Make sure no other locomotive is on the track. Instead of going into Main mode, go into Program mode. It will walk you through the set up of available CV settings. It sounds like the momentum default setting is set to allow "drift" on deceleration. I don't have my manual handy, otherwise I could tell you which setting that is. Check you manual under Program Mode.


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## Cycleops (Dec 6, 2014)

D&J Railroad said:


> What do these change? I noted CV 3 and CV 4 are set to 125. That seems to be awful high for start and stop momentum.


MrMoose it's no good telling him to change theses values if he doesn't know what he's changing. According to the Digitrax manual its CVs 2, 3, 4,5, 6 and 66 that control acceleration and deceleration. 66 being forward trim. Here's a link to that manual http://www.digitrax.com/static/apps/cms/media/documents/documentation/Decoder_Manual_V2-01_2014.pdf
By playing around with these values you should be able too achieve what you want.

CVs 3 & 4 control acceleration (3)and deceleration (4). At 125 it looks like CV4 may be set too high.


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## MrMoose (Dec 22, 2014)

GWpapa watch this video the setting that he makes will work with steam loco also.

https://www.youtube.com/watch?v=CrB4MUrrbB4


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## Brakeman Jake (Mar 8, 2009)

Another guess here...could this loco still be selected and active on another throttle?The decoder may be trying to deal with conflicting commands.This is a common occurence as we all forget to totally remove after use.I'd make sure it's completely erased from the command station's memory.


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## Gwpapa (Dec 6, 2014)

Thanks to all who responded with possible solutions to my "creep" problem. I decided to start with the most plausible solution I saw first and it worked. I checked the CV value of CV #4 which is the deceleration rate. Mine read 004 so I changed it to 001 which almost solved the problem. I still had a slight creep so I changed it to 000. Problem solved. Thanks!


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## Brakeman Jake (Mar 8, 2009)

A reading of 4 (not 0004) to CV4 should have led to a barely noticeable momentum wich tells me this decoder is defective,unless the zeros were messing it up.However,if you're happy with it this way,that's what counts.


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## Gwpapa (Dec 6, 2014)

I just saw this in the digitrax manual. 
Momentum-CV03 & CV04
Momentum is part of the LocoMotion System. Acceleration is controlled 
by CV03 and deceleration by CV04. Both come from the factory set to 
000. A range of 000 to 031 is available for both accel and decel. Try 
CV03:003 and CV04:000 as a starting point for experimenting with 
momentum.
The way I read this the original setting for CV4 was 000 but mine was 004 and I had not changed it before.


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## MrMoose (Dec 22, 2014)

I see that your using a digitrax decoder. The setting I send you was for a Tsunami sound decoder, so those setting might not work for it. Sorry about that.


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