I for one have grappled with DCC motor tuning, seems to be the devil's own business, so if you have any tips please do enlighten us.
Thanks
Tony
I don’t really know very much about motor tuning in DCC so much of this may be stating the obvious to many people . . .
My gut feeling is you need a roundy-roundy to set up any kind of acceleration and deceleration, otherwise the task is just frustrating. Somewhere the loco can reach its maximum speed and sustain it for a while. This is something I can try one day for my H0 and 00 models, I have an oval of Unitrack.
I spent some time with British H0, and I decided early on that I wanted to try out DCC because this would make controlling the trains so much easier. I settled on the Lenz Standard+ V2 as my decoder of choice because this provides six motor control characteristics (CV50), and one of these seemed to work with ever motor I could throw at it e.g. from Fleischmann Warship to Roco EE shunter.
I also bought decoders from ESU and Zimo. These seem to drive motors very well without much fiddling, but at the time I chose them more by luck than judgement.
Since then I have discovered the motor auto-tune feature (CV54=0, F1) in the ESU LokPilot v4 and v5. This is a bit hit and miss, and
@Yorkshire Dave has pointed out that you can get a different set of values on each successive run. Still, I am very happy with the results I have obtained so far with my H0 and 0 gauge models. This also needs a fair amount of track, ideally 4 metres in 0 gauge with the loco starting in the middle. I have run the sequence a few times for most models, and I like the way they now respond to the throttle.

Now I have DecoderPro and a Sprog I have had a go with complex speed curves. I like the idea of a slow start to use on my small shunting layouts along with the full maximum speed to use on the track at NEEGOG. What I really need to do is revert to to the simple speed setting and make sure the locos do start at a power level of ‘1’, and if not then adjust CV 67 and the ones nearby upwards to suit.
All but one of my 7mm locos run really well on DCC. I put this down to them already running well on an analogue controller. The exception is ever so slightly lumpy on analogue, and DCC seems to make this worse. I arranged the decoder into a socket so I can put in a blanking plug instead and then refine things using the analogue controller. I expect one of the side rods is binding ever so slightly.
I am sure, the important thing is to get models running really well on analogue before adding DCC. I find this easier in 7mm than in the smaller scales – I suppose this is because everything is that much bigger and more robust.
With a bit of luck some other people will add to this . . .