Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Stop, start loco movement in N scale

2231 views
8 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    October 2007
  • From: Melbourne, Australia
  • 6 posts
Stop, start loco movement in N scale
Posted by Peter Webster on Thursday, October 22, 2009 11:04 PM

 I have several DCC locos and all but 2 run fine. The 2 in question are an early Rivarossi N scale 4-8-8-4 Big Boy with an MRC sound equipped decoder and also a ConCor 4-8-4 GS4 which I converted myself with the same type of decoder. Other locos equipped with this decoder work fine and both locos ran perfectly before conversion. The problem is similar to a lack of amps where the loco s start off ok then suddenly stop the after 1 or 2 seconds start again. This happens randomly on the track. The track is clean and all my other units run well, these include a dcc Galloping Goose up to an Athearn Big Boy and Challenger. Can any one help with a solution.

Thanks Peter W

  • Member since
    June 2009
  • From: QLD, Australia
  • 1,111 posts
Posted by tbdanny on Thursday, October 22, 2009 11:25 PM

Peter,

Welcome to the forums!Big Smile

Now, as to your problem, have you tried using another brand of decoder in these two locomotives?  I haven't used MRC decoders myself, but from other posters, I understand that they have a few quality control issues.

Hope this helps.

tbdanny

The Location: Forests of the Pacific Northwest, Oregon
The Year: 1948
The Scale: On30
The Blog: http://bvlcorr.tumblr.com

  • Member since
    July 2008
  • 1,206 posts
Posted by mfm37 on Friday, October 23, 2009 3:21 AM

 Did you check the stall current of those two locos before choosing a decoder? The three being compared are modern DCC designed and equipped mechanisms. The two in question, while running perfectly on DC would probably draw more current when running because their mechanisms use older style motors with higher friction drives.

  • Member since
    January 2008
  • 595 posts
Posted by mreagant on Saturday, October 24, 2009 10:30 AM

Peter, I've been watching your post (first one I see) for a day to see if you got any helpful responses.  I guess you got at least one along with the to be expected shots at MRC decoders.  Let me see if I can offer something constructive.

I had a locomotive (Bachmann Spectrum Shay) that I'd run for several years in DC without any performance issues.  I had a professional installation of a sound decoder --NOT MRC--  a Micro-Tsunami.  It began doing the same thing you described as soon as I put it on the layout.  It would run a few inches (maybe) and then stop and most of the time restart.  This was particularly annoying since when it restarted, it reinitiated the steam up, whistle sequence before it began to move.

To get to the point, a very thorough re-cleaning of the track and wheels has all but eliminated the problem.  Whereas a DC engine will usually power through trouble spots, a DCC loco is often much more sensitive to a drop, even a slight one, in track power.  Some of the more electrically knowledgeable folks may step in here and explain why that is.  All I know is that seems to be the way it works.

I'm not saying that it might not be a decoder issue, but I certainly wouldn't assume that just because it is a MRC decoder, that is the source of the problem.

Good luck.

  • Member since
    October 2007
  • From: Melbourne, Australia
  • 6 posts
Posted by Peter Webster on Saturday, October 31, 2009 12:01 AM

 Yes,

       In the ConCor GS-4 4-8-4  I hav a Tsunami Micro installed but the problem still persists.

Someone on another Forum suggested heat may be a problem but the motion pattern seems too abrupt for that

Peter W

  • Member since
    October 2007
  • From: Melbourne, Australia
  • 6 posts
Posted by Peter Webster on Saturday, October 31, 2009 12:06 AM

 Yes,

 The stall current was well within the range. The Big Boy was rengined just prior to the conversion by the person who did the conversion and I know he always checks this. I also checked it when I checked the

GS 4. I also upgraded to a Tsunami Micro and the problem still persists.

Peter W

  • Member since
    October 2007
  • From: Melbourne, Australia
  • 6 posts
Posted by Peter Webster on Saturday, October 31, 2009 12:16 AM

I appreciate what you are getting at but I have tested them on brand new, unused and and cleaned track. The GS 4 had  2hrs running before conversion to loosen everything up and a bit more on the Big Boy. Both locos wheelsets and pick up were in perfectly clean condition as I know the effect of dirt on N Scale in particular. The odd ting is  that both locos run perfectly inverted in a cradle. which points to the track.

I think I will have to investigate that point a bit more.

Peter W

  • Member since
    July 2006
  • From: Etobicoke, Ontario, Canada
  • 578 posts
Posted by Blue Flamer on Tuesday, November 10, 2009 12:35 PM

Peter Webster

I appreciate what you are getting at but I have tested them on brand new, unused and and cleaned track. The GS 4 had  2hrs running before conversion to loosen everything up and a bit more on the Big Boy. Both locos wheelsets and pick up were in perfectly clean condition as I know the effect of dirt on N Scale in particular. The odd ting is  that both locos run perfectly inverted in a cradle. which points to the track.

I think I will have to investigate that point a bit more.

Peter W

 

I think that you are on the right track, (no pun intended).

1)Do you have enough FEEDERS at regular intervals from the track to your Bus wires.

2)Are your Bus wires of sufficient gauge for the size of your layout.

If the above are not the issue, I would check for loose or bad connections in your wiring and track joints and make sure that your track, wheels and wheel pick-ups are REALLY clean.

Good luck.

Blue Flamer.

"There is a very fine line between "hobby" and "mental illness"." Dave Barry, Syndicated Columnist. "There's no point in being grown up if you can't be childish sometimes." Doctor Who.

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!