Dale Posted January 21, 2013 Share Posted January 21, 2013 Hi folks, Can any one advise me on a remedy for my problematic 27. Its fitted with a Loksound 4 chip and has been run in for 30 mins in both directions on a medium speed. I am using a powercab, its OO and running on clean code 75 track. At speed step 1 (28 steps) the loco moves forward in a series of small jolts instead of smoothy advancing. On speed step 2 the jolting is still clearly noticeable but an improvement on step 1. Its not until i open the throttle to step 3 that the loco moves in what is perceptibly a smooth motion. As the layout its being used on is little more than a shunting plank I need smooth slow speed creep so help please, what should I be looking for or doing to sort out what is otherwise a lovelly loco. (its the chromatic blue one with small yellow panel's). Thanks in advance. Dale. Link to post Share on other sites More sharing options...
leopardml2341 Posted January 21, 2013 Share Posted January 21, 2013 Hello Dale, No expert on DCC - but why are you using 28 speed steps ? I'm sure the decoder you've got supports 128 and that the powercab can read and program decoder ? Have you tried selecting 128 ? Rgds Link to post Share on other sites More sharing options...
Nigelcliffe Posted January 21, 2013 Share Posted January 21, 2013 Run the Automatic motor calibration feature inside the decoder: Put loco on track with a clear 1.5m of run. Set CV54=0. Then press F1 on your controller. Loco shoots off like a scalded cat, setting various parameters in CV51 to CV55 as it goes. Consult ESU manual for the full details. Link to post Share on other sites More sharing options...
charliepetty Posted January 21, 2013 Share Posted January 21, 2013 Run the Automatic motor calibration feature inside the decoder: Put loco on track with a clear 1.5m of run. Set CV54=0. Then press F1 on your controller. Loco shoots off like a scalded cat, setting various parameters in CV51 to CV55 as it goes. Consult ESU manual for the full details. That is correct, the CV 54 self tuning will solve the issue (99% in my experience) Link to post Share on other sites More sharing options...
leopardml2341 Posted January 21, 2013 Share Posted January 21, 2013 Run the Automatic motor calibration feature inside the decoder: Put loco on track with a clear 1.5m of run. Set CV54=0. Then press F1 on your controller. Loco shoots off like a scalded cat, setting various parameters in CV51 to CV55 as it goes. Consult ESU manual for the full details. Hello Nigel, can you do this on a rolling road as well - or will it be affected by 'rolling resistance' ? Also I assume there's no effect on sound synchronisation with sound chips ? Rgds Link to post Share on other sites More sharing options...
two tone green Posted January 21, 2013 Share Posted January 21, 2013 Word of warning, do make sure that the direction you want the loco to go is selected on your controller. When it takes off at max chat, it really does go some. Link to post Share on other sites More sharing options...
Nigelcliffe Posted January 21, 2013 Share Posted January 21, 2013 Hello Nigel, can you do this on a rolling road as well - or will it be affected by 'rolling resistance' ? Probably a bad idea for most models as they're likely to leap off the rollers! Also I assume there's no effect on sound synchronisation with sound chips ? Rgds The purpose is to set the motor parameters, so it will have some minor affect on the movement speeds which relate to sound playback thresholds. They are unlikely to be negative affects, as the purpose of the settings is to make the model perform to its best, as the sound project writer intended. All the CV54 auto-tune does is to save the owner from having to optimise five different CVs which affect motor running. The autotune gets the settings very close to perfect, such that additional tweaks of those settings are rarely needed. - Nigel Link to post Share on other sites More sharing options...
Dale Posted January 21, 2013 Author Share Posted January 21, 2013 Does the track have to be straight? I only ask as I have just tried the ?calibration? on my shunting plank (8' long) and have had differing results. Sadly its not a clear 8' of straight track. Each test resulted in a different result depending on the track it was run. The head shunt gave the best result but here i think the curve may have affected things. Each time I went back in to try again the CV 54 value was different, anything from 72 to 198? Either way, the results didn't solve the stuttering problem so i guess i will lay 2m of purpose built code 100 on a plank and put some croc clips on it from the DCC bus on the shunting plank... Oh, I have also had the wheels off, given them a good clean, cleaned the contacts with IPA and checked the back to backs (they were a little tight out of the box) so on clean track, i would hope this loco should run as sweet as a nut. Is 30 mins each way enough time to bed the motor in?? Should i be doing the CV54 dash on all of my loco's to fine tune the motor controls?? D. Link to post Share on other sites More sharing options...
Sunnysa Posted January 22, 2013 Share Posted January 22, 2013 Do it on rollig road. Just make sure all wheels are seated properly on the rollers and hold the loco so it doeas'nt jump off. cheers ian Link to post Share on other sites More sharing options...
tractor_37260 Posted January 22, 2013 Share Posted January 22, 2013 Have you tried removed the capacitor (small square box) on the circuit board behind the pair of resistors. These can sometimes cause uneven running at slow speeds on DCC. If you don't want to remove it completely, try cutting one leg on it and then trying out the loco again, you can always resolder the leg later if you want to keep it in circuit, or use the loco on DC. I had a similar problem on some 26/27's but they are V3.5 fitted, adjusting CV54 and 55 cured it, as no auto-tune on these AFAIK. I use and would recommend 128 speed steps, especially for a short run layout. HTH Ken Link to post Share on other sites More sharing options...
Dale Posted January 22, 2013 Author Share Posted January 22, 2013 Well I will lay in some straight code 100 clean track today and try the CV54 again then have a look at the capacitor if it still wont run smooth and slow. Fingers crossed. D. Link to post Share on other sites More sharing options...
leopardml2341 Posted January 22, 2013 Share Posted January 22, 2013 Probably a bad idea for most models as they're likely to leap off the rollers! The purpose is to set the motor parameters, so it will have some minor affect on the movement speeds which relate to sound playback thresholds. They are unlikely to be negative affects, as the purpose of the settings is to make the model perform to its best, as the sound project writer intended. All the CV54 auto-tune does is to save the owner from having to optimise five different CVs which affect motor running. The autotune gets the settings very close to perfect, such that additional tweaks of those settings are rarely needed. - Nigel Thanks Nigel :-) Link to post Share on other sites More sharing options...
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