I have been attempting to speed match several DCC locomotives with only changing CV2 and nothing else. I seem to have had good luck getting 3 SD70ACE Athearn Genesis locomotives running together in a consist, as well as 2 Intermountain Gevo’s in the same fashion with very minimal knuckle bumping or pulling if any at all. Is this an effective way to speed match, how much variance (push or pull) can there be without doing damage to the locomotives?
You need to also adjust CVs 5 and 6, mid- and max-voltage. One locomotive pulling or pushing too hard against the others can cause the motor and decoder to overheat.
Unfortunately, Tsunami decoders do not support CVs 5 and 6, so trying to make changes to them will have no effect at all. If they are Tsunami, you need to download the Technical Reference Manual to see which CVs need to be adjusted.
When in a consist, some decoders use different CVs than 2, 5 and 6 for speed adjustment, so you need the complete technical manuals for each decoder type.
I have always found speed matching easiest using JMRI.
Richard
I’ve seen some A-B consists that were close, but not exactly speed matched. No problems while running, but after a year or so of running (5-6 times a year on a modular club layout), the plating is showing signs of wear. I guess even a little bit of slipping can cause extra wear over time. It’s not practical to get every locomotive to run exactly right every time (motors break in differently and will slowly run at a different speed over the years). I guess it all depends on your layout: do you have grades and need locos to pull a specific load over the hill, forcing the use of helpers? If you are running locos to their max pulling capability, a slight mismatch might cause a lower tractive effort which will be evident. If you’re running short trains on level track, and pulling power isn’t critical, a little bit of slip is probably ok. Worst case, you’ll have to replace wheel sets in a few years (maybe 10 years or so) which is pretty easy and not too expensive; I wouldn’t sweat a little bit of wheel slip.