MikeHunter Posted January 31, 2015 Share Posted January 31, 2015 Hi, I'm hardwiring my second Bachmann Jinty, both have Hornby chips. The one I've been working on today is running opposite to instructions forward for reverse and reverse for forward. Is it simply a wire problem and if so which, do I reverse the track wires, or chip to motor? Could the decoder have the wires in the wrong order? Any ideas really appreciated. Link to post Share on other sites More sharing options...
TheWeatheringMan Posted January 31, 2015 Share Posted January 31, 2015 Hi, I'm hardwiring my second Bachmann Jinty, both have Hornby chips. The one I've been working on today is running opposite to instructions forward for reverse and reverse for forward. Is it simply a wire problem and if so which, do I reverse the track wires, or chip to motor? Could the decoder have the wires in the wrong order? Any ideas really appreciated. Hi, No need to change any wires. Check the value of CV 29 then reprogram CV29 to reverse the 'normal direction of travel'. This information will be on the decoder instruction sheet. However if lost try deducting '1' from the value of CV29 -ie, if the known value is 35 reprogram to 34. If value is 34 then reprogram to 35. This is assuming you are using long address (4 digit). Regards Link to post Share on other sites More sharing options...
MikeHunter Posted January 31, 2015 Author Share Posted January 31, 2015 I swapped the track wires but got the same result. Link to post Share on other sites More sharing options...
tractor_37260 Posted January 31, 2015 Share Posted January 31, 2015 Hi, I'm hardwiring my second Bachmann Jinty, both have Hornby chips. The one I've been working on today is running opposite to instructions forward for reverse and reverse for forward. Is it simply a wire problem and if so which, do I reverse the track wires, or chip to motor? Could the decoder have the wires in the wrong order? Any ideas really appreciated. Change over EITHER the back and red - (track pick-up wires) OR the Orange and Grey motor wires but NOT both. Another option is to try adding 1 to the total value in CV29 HTH Ken Link to post Share on other sites More sharing options...
MikeHunter Posted January 31, 2015 Author Share Posted January 31, 2015 Change over EITHER the back and red - (track pick-up wires) OR the Orange and Grey motor wires but NOT both. Another option is to try adding 1 to the total value in CV29 HTH Ken I only swapped the track wires, and am puzzled why it didn't solve the problem. Link to post Share on other sites More sharing options...
TheWeatheringMan Posted January 31, 2015 Share Posted January 31, 2015 I only swapped the track wires, and am puzzled why it didn't solve the problem. Hi, Its because the 'normal direction of travel' is set within the decoder relative to the front of the loco. This is why a dcc loco will always run chimney first when told 'forward' no matter which way round it is placed on the track. The track power is ac and therefor whilst there is a convention as to which rail the red and black wires are conected to it actually doesnt matter as with the ac there is no 'positive' or 'negative' like dc. The correct wires to swap are the orange and grey if you must - or do the reversal via CV29 as I mentioned in my previous post. Regards Link to post Share on other sites More sharing options...
RMweb Premium Izzy Posted January 31, 2015 RMweb Premium Share Posted January 31, 2015 I only swapped the track wires, and am puzzled why it didn't solve the problem. Because it's the decoder that sets the direction, and not it's input current. You need to reverse the decoder leads to the motor to reverse the motors rotation, the orange and grey leads. Or as has been suggested change the direction set by the decoder by altering cv29. Changing the leads is probably easier. Izzy Link to post Share on other sites More sharing options...
Phil S Posted February 1, 2015 Share Posted February 1, 2015 A useful test device when digitising a loco, is a 9V battery - simply placed across the pickup wheels - It includes bulit-in identification of polarity with it '+/- markings. It is a relatively safe and convenient method of checking your digital conversion: the wheels should turn, and directional lights should operate - sound too if included. Confusingly, an earlier correspondant mentioned the option of swapping the Red/black wires from the track to change the loco's running direction (implied ON DCC). HOWEVER: DCC, as others have stated earlier, is an AC waverform /albeit not a sinewave like from a transformer, but switched alternately in each direction, ALL DECODERS full-wave rectify the track signal to derive their on-board power; therefore when used on dcc:ac, it is the 'COMMAND > FORWARD' which tellls it to 'go forth'. IF this goes 'the wrong way' then EITHER the MOTOR WIRING (orange/grey) should be swapped OR CV 29 changed between and ODD and EVEN value (as the '1' allows the default 'forward /reverse to be swapped BUT IF YOUR LOCO HAS LIGHTS - it is EASIER if you CHECK IF THESE ARE CORRECT FIRST (white wires forward and Yellow wires reverse, with a common Blue +ve ... although, in many, but NOT ALL decoders, these CAN also be changed by CVs, there are more of them (eg 4 functions) to change and get right individually!! ...... IF the LIGHTS ARE CORRECT then it is better to swap the Orange/Grey motors connections over, to get FORWARD CORRECT, if possible. However, for DC compatibility, and this is where the 'confusion' was introduced - which may or may not be important to you - it is useful if ON ANALOGUE DC the running direction is ALSO 'standard' which means that When the RIGHT is positive (from the battery terminal, as I suggested above), the loco runs forward ... so if you started with the RED wire to the RIGHT hand side when looking forward, the loco would have 'standard wiriing - consistant between all your locos, making maintenance easier. ... A FINAL CAVEAT: IF this was for a G-SCALE LOCO then the default running direction IS / WAS the other way ..... which can cause 'hiccups' at G-Scale meetings ...because.. in Analogue, and original LGB MTS (dcc, 14 speed steps) the convention is 'the other way' - But users of more generic dcc (eg Massoth add-ons changing it to 28 speed steps) are more likely to follow the 'standard dcc convention. and most Bachmann G Scale products (such as Thomas) include a Direction Change Switch as an 'instant solution'. WHOOPS: A Futher opportunity to get it wrong: The Hornby 'SELECT* and which Button thinks is 'FORWARD* .... they use the button pointing to the LEFT. Link to post Share on other sites More sharing options...
gordon s Posted February 1, 2015 Share Posted February 1, 2015 Because it's the decoder that sets the direction, and not it's input current. You need to reverse the decoder leads to the motor to reverse the motors rotation, the orange and grey leads. Or as has been suggested change the direction set by the decoder by altering cv29. Changing the leads is probably easier. Izzy It takes a few seconds to reprogramme CV29 versus taking off the body and rewiring. Even easier on a NCE Powercab.... Link to post Share on other sites More sharing options...
AMJ Posted February 1, 2015 Share Posted February 1, 2015 When I hard wire chips I use a multimetre to determine which wires are connected to left rail and which wire it is on the motor and the same for right. If you use the resistance setting a 0 value indicates there is a direct wire connection a figure in ohms shows the resistance of the motor. It is always good idea to set the chip back to factory, ensure the red & black go to the track orange & grey the other way are wired as they should be. If you reset the chip or change the programming on it you don't want to experience a loco running the wrong way. [Edit] One thing that Ido these days is to put in a harness and plug so that if in the future I decide to change the chip it's an easy swap out. As an example my Hornby Sentinel diesel shunter has a 6pin harness and chip in it. Link to post Share on other sites More sharing options...
Crosland Posted February 1, 2015 Share Posted February 1, 2015 I only swapped the track wires, and am puzzled why it didn't solve the problem. You were given duff advice. Swapping the track wires will make no difference unless its a Lenz, or other decoder, supporting Asymmetric Braking, inwhich case the ABC functionality wil be upset. Andrew Link to post Share on other sites More sharing options...
MikeHunter Posted February 1, 2015 Author Share Posted February 1, 2015 Thanks for all the help. Finally managed to reset cv29 and the loco is responding correctly now. I realise I have a lot to learn about operating DCC. Reading the manual for my power cab I realise I've only mastered the basics so far. Link to post Share on other sites More sharing options...
gordon s Posted February 2, 2015 Share Posted February 2, 2015 When setting up a loco with a Powercab, one of the programming steps is to ask you whether or not you want forward or reverse direction and you don't need to specifically change CV29 as it is automatically done. From memory there are only four or six simple questions re operating number, short or long address etc and use of a speed table to which you only have to answer yes or no. If you need any pointers, there are many of us using Powercabs on here that will be pleased to help. Link to post Share on other sites More sharing options...
MikeHunter Posted February 5, 2015 Author Share Posted February 5, 2015 When setting up a loco with a Powercab, one of the programming steps is to ask you whether or not you want forward or reverse direction and you don't need to specifically change CV29 as it is automatically done. From memory there are only four or six simple questions re operating number, short or long address etc and use of a speed table to which you only have to answer yes or no. If you need any pointers, there are many of us using Powercabs on here that will be pleased to help. Thanks for the help. I love the Powercab, never would have gone DCC if I hadn't bought a DCC wired layout off eBay. It's a shunting plank, and DCC really makes the difference operating it. I've just chipped my 10th loco, still 30 to go, but there are limits on what I can run, the streamlined Duchesses would look a bit silly..... Link to post Share on other sites More sharing options...
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