Sionytren Posted January 29, 2014 Share Posted January 29, 2014 I am trying to get my Std 4T working ready for Doncaster. The chip is fitted and wired ok. No response from the chip on the programming track, eventually we gained access via the CVs. The new chip shows the identification No 3 as expected but we can get no output to the motor from the chip. It has been suggested that the frequency needs to be changed for coreless motors and I can find no information on how to do it and what settings to use. The info with the OPTI chip indicated that it is suitable for coreless motors. Any ideas? Link to post Share on other sites More sharing options...
TWG Posted January 30, 2014 Share Posted January 30, 2014 Your problem has nothing to do with the output frequency of the decoder. There are very few decoders, if any, these days which do not have the high frequency necessary for coreless motors. The OPTI, as you confirm, is suitable and no adjustment is required (or probably possible). If the CVs can be read, electricity must be reaching the decoder. If you have measured the output (and are not assuming that there is none because the motor does not turn) it seems likely that the decoder is defective. Do the lights (F0) come on; do any further function outputs work? Link to post Share on other sites More sharing options...
Crosland Posted January 30, 2014 Share Posted January 30, 2014 If the CVs can be read then power is getting to the motor, as it's the current detected when pulsing the motor on and off that allows CVs to be read. Have you tried resetting the decoder? Andrew Link to post Share on other sites More sharing options...
Sionytren Posted January 30, 2014 Author Share Posted January 30, 2014 Many thanks for the replies. We tried several chips from the same packet, some of which are operating well in other locos. We checked the output voltage from the chip to the motor when asked to run, the output showed 0 volts. While attempting to access the chip the motor moved the loco about 3 ins then stopped, we don't know why. The loco has run well on DC so the motor is OK. Link to post Share on other sites More sharing options...
Nigelcliffe Posted January 30, 2014 Share Posted January 30, 2014 Check motor carefully, I have seen a Portescap with a dead coil in the motor. Would run if pushed away from the dead coil, but if it stopped at the dead coil, it would not restart. Replacement motor was the answer (any similar sized coreless with the same industry standard screw nose will fit ). You could turn off the BEMF controls in the chip to see if that's confusing the chip; it won't give you brilliant running, but might confirm all is working. I'd try a different chip. I've never had a problem with Zimo on Portescaps. I did run into some difficulties with a CT DCX75 on a Portescap; would run but somewhat erratic, swapping for a slightly higher powered chip solved it (CT's are wonderful on smaller coreless 1016 and 0816 motors, but for some reason took exception to the slightly larger motor's demands). Link to post Share on other sites More sharing options...
Sionytren Posted January 30, 2014 Author Share Posted January 30, 2014 Many thanks for your reply. We'll try that after Doncaster. I've had to withdraw the loco as the valve gear on the fireman's side has failed and I don't have time to fix it - in addition to completing some modelling and making it filthy to suit the layout. I may have to buy a Zimmo - that name has been mentioned at the club. Link to post Share on other sites More sharing options...
Crosland Posted January 31, 2014 Share Posted January 31, 2014 While attempting to access the chip the motor moved the loco about 3 ins then stopped, we don't know why. See my first answer. Reading and writing CVs causes the motor to be pulsed. Some locos creep more than others. This shows that the deocder is capable of providing power to the motor. Andrew Link to post Share on other sites More sharing options...
RMweb Premium Torper Posted January 31, 2014 RMweb Premium Share Posted January 31, 2014 I've never had a problem with Zimo on Portescaps. Does that mean they'll run with the default Zimo settings, or is some alteration usually required to the CVs? DT (still trying to come to terms with the complexities of DCC, but completely won over by its benefits) Link to post Share on other sites More sharing options...
RMweb Premium Mallard60022 Posted January 31, 2014 RMweb Premium Share Posted January 31, 2014 I seem to remember someone (was it Geoff from Comet?) that there can be problems with Portescap and DCC. However I might have just dreamed that. Comet now have a range of coreless motors that are (by reputation) quieter than Portescap and are better 'haulers'. You could ask Geoff if they are DCC compatible? The cost of the Portescap remnants on Ebay are silly money. Geoff's products are very cost competitive. P Link to post Share on other sites More sharing options...
Nigelcliffe Posted January 31, 2014 Share Posted January 31, 2014 Does that mean they'll run with the default Zimo settings, or is some alteration usually required to the CVs? DT (still trying to come to terms with the complexities of DCC, but completely won over by its benefits) They should be OK out of the box, though I always spend time tuning decoders to match a model. The Zimo manual has clues as to what to change. I seem to remember someone (was it Geoff from Comet?) that there can be problems with Portescap and DCC. However I might have just dreamed that. Comet now have a range of coreless motors that are (by reputation) quieter than Portescap and are better 'haulers'. You could ask Geoff if they are DCC compatible? The cost of the Portescap remnants on Ebay are silly money. Geoff's products are very cost competitive. P There is nothing magical about the motor on a Portescap motor-gearbox. The last one I repaired had pretty much the same markings(*) on the body as a Faulhaber (www.Minimotor.ch). It was a Faulhaber from my spares box which was used to replace the faulty motor. The gearbox on the Portescap is a little different to the usual, being bevel gears which can be driven backwards, rather than worms which cannot. Its the gearbox which can be noisy, not the motor. There are numerous options which I think are superior to the Portescap combination; the "standard" High Level gearbox plus a Mashima motor would be my suggestion. The issue for some people is the ability to drive the gearbox backwards, rather than just a forward worm drive. The new Comet gearbox/motor combination allows back-drive (though you pay quite a lot for the facility), and has a significantly larger motor than the Portescap I repaired recently. The choice of a Maxon motor seems sensible, usually lower RPM for peak torque than the equivalent sized Faulhaber. Coreless motors are fine on DCC chips which use high frequency PWM output (above 10kHz). That's pretty much every chip on sale today. Back in the early days of DCC, nearly 20 years ago, there were a number of DCC chips which worked at low frequencies (around 150Hz), those could lead to problems with a coreless motor, in much the same way as simple low-frequency PWM DC controllers are bad for coreless motors. I agree that Portescap remnants seem to fetch silly money, alongside various other bits of antique model railway stuff. (* I'd have to see if its still in my junk box to confirm its exactly the same markings as a Faulhaber motor. ) - Nigel Link to post Share on other sites More sharing options...
Gordon H Posted January 31, 2014 Share Posted January 31, 2014 Many thanks for your reply. We'll try that after Doncaster. I've had to withdraw the loco as the valve gear on the fireman's side has failed and I don't have time to fix it - in addition to completing some modelling and making it filthy to suit the layout. I may have to buy a Zimmo - that name has been mentioned at the club. If you bring it along to Doncaster anyway and visit the MERG stand, it might be possible for us to make a diagnosis there. Link to post Share on other sites More sharing options...
Horsetan Posted January 31, 2014 Share Posted January 31, 2014 ....The issue for some people is the ability to drive the gearbox backwards,.... I consider this a "must", and will not use worms. Link to post Share on other sites More sharing options...
Sionytren Posted February 1, 2014 Author Share Posted February 1, 2014 Hi Gordon - Many thanks for the offer, I'll bring it along if I make it to Doncaster myself. There is some doubt at the moment - the club is still coming with the layout though. Link to post Share on other sites More sharing options...
Sionytren Posted February 14, 2014 Author Share Posted February 14, 2014 Hi Gordon - I did make it to Doncaster, but didn't take the loco with me. We checked the CVs however and CVs 9 and 10 are both set to zero. When the post exhibition flurry of actions to sort out niggles on the layout are well in hand, I will try the loco again. Link to post Share on other sites More sharing options...
RMweb Gold chris p bacon Posted August 17, 2015 RMweb Gold Share Posted August 17, 2015 I've resurrected this thread as time and technology move on. I've a 1219 with RG4 box and will be looking for a decoder for it, motor and box are suitable as they fit in the boiler of a Stirling single, are there any new thoughts on a specific decoder for this motor ? Space is obviously an issue with this one. Link to post Share on other sites More sharing options...
RMweb Gold geoff Posted August 17, 2015 RMweb Gold Share Posted August 17, 2015 I've resurrected this thread as time and technology move on. I've a 1219 with RG4 box and will be looking for a decoder for it, motor and box are suitable as they fit in the boiler of a Stirling single, are there any new thoughts on a specific decoder for this motor ? Space is obviously an issue with this one. Most modern decoders offer high frequency sampling and motor control so take your pick based on preferred manufacturer, size or price. I currently use a Digitrax DZ143 with a Portescap with very low bemf settings, I also have a small Zimo running another Portescap fitted loco. Geoff Link to post Share on other sites More sharing options...
RMweb Gold chris p bacon Posted August 17, 2015 RMweb Gold Share Posted August 17, 2015 Most modern decoders offer high frequency sampling and motor control so take your pick based on preferred manufacturer, size or price. I currently use a Digitrax DZ143 with a Portescap with very low bemf settings, I also have a small Zimo running another Portescap fitted loco. Geoff Thanks Geoff, for a lot of stock I've just used basic decoders and tend not to alter the settings, size is going to play a part with this so I'll probably pop into Digitrains end of the month when we are there for the day , do you alter anything specifically for the motor ? Link to post Share on other sites More sharing options...
RMweb Gold geoff Posted August 17, 2015 RMweb Gold Share Posted August 17, 2015 Thanks Geoff, for a lot of stock I've just used basic decoders and tend not to alter the settings, size is going to play a part with this so I'll probably pop into Digitrains end of the month when we are there for the day , do you alter anything specifically for the motor ? Apart from the address I look to set the BEMF to give smooth running through the full range but with a Portescap you should not need very high settings to achieve that. I set the acceleration and deceleration, CVs 3 and 4, to suit the loco and the type of trains it will be pulling. There is often a function which can be used to disable these settings for when the loco is running light. I nearly always use the speed table to set the start speed on speed step one to just moving and the top speed to suit the loco and then have a straight line graph between them. I should say that I do this using Decoderpro from the JMRI free software but of course you need a computer connected to the layout to do this. Programming on the main or Ops mode is best for all this. I would think the guys at Digitrains would be able to advise on all of this and perhaps demonstrate the use of the JMRI software. Geoff Link to post Share on other sites More sharing options...
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