LJC Posted July 16, 2013 Share Posted July 16, 2013 Wondering if anyone can help. I bought a 2nd hand Bachmann Class 20 and just ran it for the first time, it goes the opposite way from the controller direction which is the wrong direction for all the other locos. Have taken the body off and there does not appear to be any mods etc carried out. Any idea how to resolve. Cheers LJC Link to post Share on other sites More sharing options...
brossard Posted July 16, 2013 Share Posted July 16, 2013 Is it DCC? If so you can reverse direction by changing CV29 by 1. John Link to post Share on other sites More sharing options...
LJC Posted July 16, 2013 Author Share Posted July 16, 2013 John, The loco is D8307 (32-032), DCC ready, looks like the blanking plate only is fitted. If the previous owner had it on DCC then removed the chip from the loco could it now being out of sync ? Apologies if I'm talking guff but I no zilch about DCC. Cheers LJC Link to post Share on other sites More sharing options...
brossard Posted July 16, 2013 Share Posted July 16, 2013 OK, LJC, looked up the stock # and confirm it is DCC ready. With the blanking plug installed the loco is DC and its' direction is governed by the way the wires are connected to the motor, any previous DCC set up will have no effect. So, either the previous owner did change the wires round (can't imagine why) or it was made that way (most unlikely). For myself, if I was sure that the wires were wrong, I wouldn't hesitate to correct it. As it is I don't have enough info to recommend that. Perhaps someone with more knowledge of this will respond. John PS, it occurred to me as I was writing the above that the previous owner might have put the blanking plug on backwards, but I don't know what effect this would have on running (I did ask on Google but couldn't find an answer). Link to post Share on other sites More sharing options...
RMweb Premium newbryford Posted July 16, 2013 RMweb Premium Share Posted July 16, 2013 PS, it occurred to me as I was writing the above that the previous owner might have put the blanking plug on backwards, but I don't know what effect this would have on running (I did ask on Google but couldn't find an answer). The blanking plug works in either orientation. It does sound like the two motor leads have been swapped. 2 minutes with a soldering iron to fix. The other possibility is the pickup leads, but that would require two pairs to be altered. John, The loco is D8307 (32-032), DCC ready, looks like the blanking plate only is fitted. If the previous owner had it on DCC then removed the chip from the loco could it now being out of sync ? Cheers LJC No - the direction is reversed within the decoder itself. Replacing it with a blanking plug and the loco will revert back to it's original DC directions. Cheers, Mick Link to post Share on other sites More sharing options...
RMweb Premium Gwiwer Posted July 17, 2013 RMweb Premium Share Posted July 17, 2013 I have one loco which exhibits this trait. The motor is wired bottom-about-face. If you can't rewire it yourself and you also can't live with it running in the opposite direction then get the motor rewired by someone who can. I simply turn the control knob the other way when the loco in question is in use but that won't fix the problem if more than one locon is on the same circuit! Link to post Share on other sites More sharing options...
SRman Posted July 17, 2013 Share Posted July 17, 2013 You can always do a Gomez Addams reenactment! More seriously, if you can use a soldering iron, swap the two wires feeding the motor brushes. It may be possible to swap them at the PCB end - some Bachmann models have push-on plastic retainers to hold the wires onto the contacts, others require soldering anyway; you'll just have to have a look at the PCB to ascertain which applies to your model. Link to post Share on other sites More sharing options...
meil Posted July 17, 2013 Share Posted July 17, 2013 It's been modified to run nose to nose with another 20. Link to post Share on other sites More sharing options...
LJC Posted July 17, 2013 Author Share Posted July 17, 2013 Guys, Thanks for the help so far. LJC Link to post Share on other sites More sharing options...
LJC Posted July 17, 2013 Author Share Posted July 17, 2013 It's been modified to run nose to nose with another 20. If I put it nose to nose with another 20 they pull away each other. Link to post Share on other sites More sharing options...
RMweb Premium melmerby Posted July 17, 2013 RMweb Premium Share Posted July 17, 2013 It's been modified to run nose to nose with another 20. If you turn around a dc loco doesn't it still go the same physical direction? e.g. left to right or right to left, whichever it originally went. Keith Link to post Share on other sites More sharing options...
RMweb Premium Gwiwer Posted July 18, 2013 RMweb Premium Share Posted July 18, 2013 If you turn around a dc loco doesn't it still go the same physical direction? e.g. left to right or right to left, whichever it originally went. Keith Correct. So if you have two correctly-wired 20s and couple them nose to nose they will both travel in the same direction. If you couple them cab to cab or nose to cab they will still both run in the same direction because the current potential in the track remains the same. If you have one which is wired correctly and one wired the opposite way round then no matter how you couple them they will run in opposing directions. Link to post Share on other sites More sharing options...
Crosland Posted July 18, 2013 Share Posted July 18, 2013 If you turn around a dc loco doesn't it still go the same physical direction? e.g. left to right or right to left, whichever it originally went. Keith Correct, you've reversed the polarity to the motor which now spins the other way, but you have also turned the loco around so "the other way" is the same as it was. This confuses some people when moving from analogue to DCC. Andrew Link to post Share on other sites More sharing options...
RMweb Premium melmerby Posted July 18, 2013 RMweb Premium Share Posted July 18, 2013 Reversed wiring in a loco might not be as rare as one thinks. I have two Hornby (ex Airfix) GWR 2-6-2Ts, an oldish one without a DCC socket and the latest version with a DCC socket. Both are reversed! Keith Link to post Share on other sites More sharing options...
RMweb Premium newbryford Posted July 18, 2013 RMweb Premium Share Posted July 18, 2013 Correct, you've reversed the polarity to the motor which now spins the other way, but you have also turned the loco around so "the other way" is the same as it was. This confuses some people when moving from analogue to DCC. Andrew There are two "confused" notes. If a DC loco goes from left to right when the controller is turned, it will still go left to right if you turn the loco 180 degrees and place it back on the track, if you do not reverse the DC/analogue controller. On DCC - each loco has a designated "forwards". (Steam locos are easy, forwards is the chimney.) If a loco goes "forwards" from left to right when addressed to move by the DCC control, it will go from right to left when it is turned through 180 degrees, if you do not reverse the DCC controller. i.e it will still go "forwards". Cheers, Mick Link to post Share on other sites More sharing options...
RMweb Premium kevinlms Posted July 18, 2013 RMweb Premium Share Posted July 18, 2013 It's been modified to run nose to nose with another 20. Was the loco standard as built and someone has modified the wiring to make it go backwards as a pair (nose to nose), rather than reverse the direction in the decoder? Link to post Share on other sites More sharing options...
LJC Posted July 19, 2013 Author Share Posted July 19, 2013 Had the body of the and nothing seems to have been tampered with, if it has it's a very good soldering job.. LJC Link to post Share on other sites More sharing options...
davetheroad Posted July 19, 2013 Share Posted July 19, 2013 The body is on the chassis back to front? Mmm, perhaps not Link to post Share on other sites More sharing options...
RMweb Premium melmerby Posted July 26, 2013 RMweb Premium Share Posted July 26, 2013 Just to let everyone know, I have just purchased a new Bachmann 57XX pannier tank (8709) and the DCC socket is fitted reversed compared to the previous one of these I have with the same DCC ready chassis. Reverse wired locos are, as I said earlier, not uncommon! The early GWR RODs had to be returned for correction because they were completley back to front, even though previous models were OK. IMHO The Class 20 was probably wired up reversed from the factory. Keith Link to post Share on other sites More sharing options...
MikeOxon Posted July 27, 2013 Share Posted July 27, 2013 There's an exploded view of the Bachmann Class 20 in the review at http://www.modelrailforum.com/reviews/Bachmann-Class-20/DSCF8499-800.jpg This shows the, presumably correct, orientation of the red and black wires along the loco, including the motor tag and the connections at the DCC board. This might reveal if yours is reversed. Mike Link to post Share on other sites More sharing options...
RMweb Premium melmerby Posted July 27, 2013 RMweb Premium Share Posted July 27, 2013 There's an exploded view of the Bachmann Class 20 in the review at http://www.modelrailforum.com/reviews/Bachmann-Class-20/DSCF8499-800.jpg This shows the, presumably correct, orientation of the red and black wires along the loco, including the motor tag and the connections at the DCC board. This might reveal if yours is reversed. Mike On the 57XX I mentioned the DCC board had been fitted backwards, rather strangely all the wiring had been made the right length to connect to the PCB in the reversed position but to the correct solder points. It's almost as if the wiring is not of pre-cut lengths but is made to fit by whoever assembles it. Strictly speaking the wiring wasn't reversed, just the socket position, but it meant the decoder had to be fitted with the plug the other way around. As I was following the layout of a previously converted loco it caught me out! Keith Link to post Share on other sites More sharing options...
LJC Posted August 9, 2013 Author Share Posted August 9, 2013 Traced the problem, the wires to the motor/brushes were the wrong way round, soldered correctly and works like a dream. Thanks to all. Cheers LJC Link to post Share on other sites More sharing options...
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