Motor Control - CV Settings

[russ daley]

I understand there are many variables, but curious where you guys and gals who run the older (2000-2005) Spectrum 2-8-0's and 4-6-0's, with no sound and on a 28 Speed step mode, set CV2, CV6 and CV5 for a realistic speed? I also have some engines that have decoders in them with CV6 identified as Page/Pointer Register whatever that is...I'm slowly replacing them as I believe they are giving me issues like stalling...speed changes...etc.

Thank you...     

[jward]

Would these perhaps have the Bachmann factory installed decoders? The ones used in the diesels do not support CV5 or CV6 so setting a speed curve or slowing their top speed is not possible. To be able to do that you;d have to replace the decoder with one that supports those CVs.

[russ daley]

Lenz 1025 Gold...They are probably 20 years old...Anyways, I replace two engines today with brand new decoders, engine performance  greatly improved with Factory Defaults. I just wanted to make sure that my settings were adequate in a few existing and I was getting full benefit of a speed curve. For several engines, I was setting Start Voltage at 3, Mid Voltage at 175, Max at 250. Results were acceptable.     

[jward]

My approach was to take a benchmark locomotive, run it at top speed over a timed course to calculate its speed in scale mph, figure out where I wanted top speed to be as a percentage of that (i.e.100 mph actual versus 50 mph desired + 50%) then adjust cvs 5 and 6 to that percentage. Test run to see how it performs, then make any adjustments from there. Once that was done, I'd do the same to the rest of the fleet, and tweak them so they ran at exactly the same speed as the benchmark loco. I run diesels mostly, so speed matching is necessary to run consists. For steam, unless you intend to doublehead them it's not as critical that they perform exactly alike.