Want a slow start up

Model Railroader Electronics and DCC
1

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

2

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

3

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

4

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.

5

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 .

6

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

7

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

8

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.