I’m new to the hobby in general and am currently in the process of converting from straight DC ops to DCC. So far, evertying has been pretty smooth, but I have enocuntered one issue that I can not resolve.
I have been running an IHC Command XX locomotive that, although light on detail, is one of the quietest and smoothest running locos, with some of the best slow speed performance that I have ever had–while running DC. I plugged in an NCE 141p, the same series of decoder that I have been using on other makes of locos, and despite adjusting every relative CV value including starting voltatge, torque, kick,etc., I can not achieve anything close to the same slow speed performance I can with DC. I had always thought the ability to fine tune CV values with DCC would only enhance, well, at least not degrade locomotive performance. Hopefuly, some of you with a lot more experience might have a suggestion. Trial and error is only fun for a while.
Not all decoders have BEMF, which allows the decoder to sense the back current produced by a motor as it rotates. When sensitive to BEMF (Back Electro-Motive Force), the decoder can tweek pulses so that the motor turns as slow as you’d like it to, or thereabouts. My guess is that this decoder does not have BEMF sensitivity.
Adjust CVs 116 and 117 according to the instructions that came with the decoder. These adjust the kick voltage for slow speed operation and NCE’s equivalent of BEMF.
Thanks for the response. I played around with both CV116 and CV117 through their full ranges. I have discovered that I can slow the locomotive down from track speed to a nice, slow crawl; I just can not get it moving in the same range again from a stand still. I am using NCE decoders successfully across the board, and except for this particular unit, DCC has improved the performance of all the others, especially at the slowest speeds. I understand that the addition of DCC to an otherwise mediocre locomotive shouldn’t be expected to work a miracle, but worse performance than plain old DC? That is what has me stumped. I guess this is part of the fun of playing around with something new and I’m having a great time doing it!
For that particular engine, you probably need to create a custom speed table. If you have a computer you can download Decoder Pro to create the speed table, and there’s a thread buried here somewhere on how to use Decoder Pro without having it connected to a layout or programmer.
I’m surprised you’re having the problems you describe with this locomotive. I have one that I installed a SoundTraxx Heavy Steam Tsunami sound decoder into and it will creep very smoothly.