I’m new to DCC and programming CVs. I’ve just installed a TCS decoder in a Model Power 0-6-0T, formerly DC. All is working beautifully, but the engine accelerates aggressively and tops out at an unrealistically high speed–just like it did on DC.
I think I know I have the options of adjusting Start, Mid, and Top voltages, modifying speed curves, and/or changing the values of the loadable speed tables.
My goal is to limit the top speed and accelerate smoothly to get there. Can anyone point me in the right direction and give me some guidelines as to the values with which to start? Is it trial and error or will a few standard steps do it?
(I did search for prior posts to help me but didn’t find anything to fit the bill.)
Rick, what DCC system are you using? Do you have a computer interface with it?
The reason I ask is that this type of thing is so simple using the free Decoder Pro application. The speed curve user interface allows you to quickly set up the type of speed response that you want.
Failing that, then IMO the simplest thing to do is to adjust CV’s 2, 6 and 5 Start, Mid and Max respectively. Try entering CV2 =2 CV6 = 48 CV5 = 98 as a start.
Just increase/decrease CV5 to change the top speed to your liking and then adjust CV6 to be about half way between CV2 and CV5
Step 1: Set CV2 (Starting voltage). Put the loco on the track and set your throttle to speed step 1. Keep entering larger and larger numbers into CV2 until the loco starts to creep on speed step 1. Some locos require a value of 0 (typically Kato or Atlas) while others are pushing a setting of 70-90 (Athearn).
Step 2. Set CV5 (Max voltage). Put the loco on the track and set the throttle to max. Start with a good Catholic setting for CV5 (around 60 or so) and see if you want the loco to go faster or slower at max speed. If you want it to go faster, then enter in a higher number, if slower, lower.
Step 3. Set CV6 (Mid voltage). Just give this a value of HALF of CV5.
Step 4. Set CV3 (Acceleration Momentum). Play with this…this is all about personal taste. The larger the value, the longer it take the loco to speed up.
Step 5. Set CV4 (Braking Momentum). Some set this the same as CV3, but other (including myself) give it a lower value allowing you to brake faster than you can accelerate.
HOWEVER…you have a Model Power 0-6-0. I wouldnt expect that this loco will ever be able to start or stop smoothly…The Bachmann Spectrum 0-6-0T is a much, much better loco and will do exactly what you are looking for.
Thanks, Simon. I have an NCE Power Pro system. I haven’t looked into Decoder Pro, although I’ve heard of it. I’ll check it out and in the meantime try your suggestion, which I appreciate.
As others have suggested adjusting CV2, 5, and 6. Most of the time adding a little momentum in CV3 and some deceleration in CV4 will smooth out your speed demon. The newer TCS decoders have great BEMF that is enabled in CV61. When you find the start voltage setting in CV2 enable the BEMF in CV61. If you don’t want BEMF than adjust Dither in CVs 57 and 56. Keep notes on the changes you make and test it after every CV change that way you can change it back if you don’t like the change without doing a reset.