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B unit faster than A unit in Consist

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JRP
  • Member since
    November 2006
  • From: Upland, CA
  • 301 posts
B unit faster than A unit in Consist
Posted by JRP on Tuesday, January 4, 2011 12:12 AM
I have two new Proto 2000 E8/9 units and have set them to consist. But the "B" unit runs a bit faster than the "A" lead unit. The A unit address has been set to run both in the consist. The CV's for acceleration and voltage are both the same in each unit. How can I get them both to run at the same speed in the consist? Thanks. JRP
  • Member since
    February 2002
  • From: Westchester NY
  • 1,747 posts
Posted by retsignalmtr on Tuesday, January 4, 2011 5:34 AM

You have to speed match the two units to run at the same speed at the same throttle setting. Just setting the CV's to the same value does not mean they will run at the same speed.  Set CV's 3 and 4 to 0. Then set CV's 2, 5 and 6 for each loco seperatly to whatever value that will have the locos moving together.  

  • Member since
    September 2004
  • From: Dearborn Station
  • 24,281 posts
Posted by richhotrain on Tuesday, January 4, 2011 9:57 AM

retsignalmtr

You have to speed match the two units to run at the same speed at the same throttle setting. Just setting the CV's to the same value does not mean they will run at the same speed.  Set CV's 3 and 4 to 0. Then set CV's 2, 5 and 6 for each loco seperatly to whatever value that will have the locos moving together.  

retsignalmtr is correct.  Speed matching is the way to do it.  No two engines, even identical units from the same manufacturer, ever run at identical speeds.

Rich

Alton Junction

  • Member since
    May 2008
  • 4,612 posts
Posted by Hamltnblue on Tuesday, January 4, 2011 2:34 PM

How much different are the speeds?  If they are close it's all you need.  Once you put a train behind it things should even out.

Springfield PA

  • Member since
    January 2010
  • From: Denver, CO
  • 3,576 posts
Posted by Motley on Tuesday, January 4, 2011 6:45 PM

Ya ya, I just did the same exact thing on some new E7 AB units I recently got. I ended up using the speed tables using JMRI, it was pretty easy. They don't run exactly perfect, but with a train they work well. And they will always be coupled together anyways.

So don't scratch your eyes out trying to make them run perfect. Good is close enough.

Michael


CEO-
Mile-HI-Railroad
Prototype: D&RGW Moffat Line 1989

JRP
  • Member since
    November 2006
  • From: Upland, CA
  • 301 posts
Posted by JRP on Wednesday, January 5, 2011 12:22 AM
You're right...speed match works. My B unit was running faster than the A unit and I was concerned that it would be "pushing" the A unit all the while. But I lowered the CV2 (voltage) on the B unit, and slightly increased it on the A unit and tested both at different throttle speeds. That seemed to do the trick. They are almost identical now. Thanks. JRP
  • Member since
    February 2002
  • From: Westchester NY
  • 1,747 posts
Posted by retsignalmtr on Wednesday, January 5, 2011 7:44 AM

Thank you for posting what you did to correct your problem. Many posters who have problems never reply with the results of what they did to correct the difficulty and leave everyone hanging.

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