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Want a slow start up

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JRP
  • Member since
    November 2006
  • From: Upland, CA
  • 301 posts
Want a slow start up
Posted by JRP on Sunday, November 8, 2009 10:33 PM
I have an old Athearn GP35 with new NWS can motor and NCE D13SR decoder (motor and light functions only). It works, but I can't get the motor to "creep" at a slow start. Instead it starts moving forward quickly only after I turn the throttle up to about number "2" speed on my DCC system (Zephyr). Can I correct this by making adjustments on CV2? I read this configuration variable can set the starting voltage and fine tune the motor. Or is there something else I should be looking at? Thanks. JRP
  • Member since
    June 2009
  • From: QLD, Australia
  • 1,111 posts
Posted by tbdanny on Sunday, November 8, 2009 11:23 PM

JRP,

This is correct - adjusting CV2 should allow you to have a reasonable slow speed to start with.  What does your decoder manual say about this CV?

What I would suggest doing is programming it to a value of '1', then keep increasing this value until the loco gives you the performance you want at speed step 1.

Hope this helps,

tbdanny

The Location: Forests of the Pacific Northwest, Oregon
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Moderator
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Posted by tstage on Monday, November 9, 2009 7:41 AM
John,

Tweaking CV2 should help some.  For the best low-speed response, however, you should get a decoder that has back EMF or BEMF.  The NCE D13SR decoder does not come with BEMF.  BEMF really allows your locomotives (e.g. switchers) to creep along at speed step 001.

Tom

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Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by cacole on Monday, November 9, 2009 9:21 AM

 Programming a custom speed table into the DA13SR decoder can improve performance if you have Decoder Pro or know how to manually calculate a speed curve.

  • Member since
    March 2009
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Posted by C&O-CSX on Monday, November 9, 2009 4:56 PM

The NCE D13SR also has a nice feature called ( Kick Rate ) 

CV 116 = kick rate and CV 117 =  Kick Strength low speed.  Kick strength low speed is very nice for switching you can keep CV 2 setting low and still have good slow speed power.  I set CV 116 = 2 and CV 117 = 10 or 15 .

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Posted by locoi1sa on Monday, November 9, 2009 4:59 PM

 John

 There are 3 different CVs to adjust to get your loco moving slowly. CV2, CV116 and CV117. Page 3 of these instructions will explain all.

 http://www.ncedcc.com/pdf/d13sr.pdf 

     Pete

 I pray every day I break even, Cause I can really use the money!

 I started with nothing and still have most of it left!

  • Member since
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  • 311 posts
Posted by Harley-Davidson on Thursday, November 12, 2009 2:43 PM

JRP, in my experience, an ESU Lokpilot 3.0 decoder has the better slow motion in the market.

  • Member since
    February 2002
  • From: Mpls/St.Paul
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Posted by wjstix on Thursday, November 12, 2009 4:10 PM

You're probably going to end up with a fairly high value in CV2. If you're putting it up to the second marker on the Zephyr, that's about 30-40% full throttle. Older Athearn motors often need more juice to turnover than newer can motors, I'd guess you'll end up with CV2 being around 30 or more. You can then adjust CV 3 (starting momentum) to lengthen the time between speed steps to make the engine come up to speed smoothly.

Stix

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