Aristo A and B unit running issues

scook

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Advice needed please, I have recently converted an aristo b unit to dcc via a massoth XL decoder, the same massoth decoder is fitted to the a unit, both run fine on dcc, when placed on an analogue track the b unit runs in the opposite direction, even when turned around, both decoders are set up the same, ie speed steps etc, there is also a track pick up cable bridging the two units and nothing shorts on dcc or analogue, any ideas welcome
 
Advice needed please, I have recently converted an aristo b unit to dcc via a massoth XL decoder, the same massoth decoder is fitted to the a unit, both run fine on dcc, when placed on an analogue track the b unit runs in the opposite direction, even when turned around, both decoders are set up the same, ie speed steps etc, there is also a track pick up cable bridging the two units and nothing shorts on dcc or analogue, any ideas welcome
There will be a CV that sets the direction of the motor,

But I don't have the information to hand....
 
When you physically turn a loco round on the track, you not only reverse the polarity of the power being picked-up, but also the connection to the motor. - So the motor turns the opposite way.

If this was not so, it would be pot-luck, which way an analogue loco would run when you turned your controller 'forwards'.

Aristocraft bogies are a pain, as they are quite often wired the same, so you have to be careful to get the correct polarities wired together, irrespective of the colour of the wires.
There is not a great deal of consistency with which way round the motors are in the bogies, either.

I would start by running the two units a foot or so apart, both DC and DCC.
If you also have rollers, check the individual bogies are running in same direction. - You may be able to check this by lifting one end of the unit off the track.

PhilP
 
Just swap the track feed to the decoder on the B unit & it should work OK.
 
How about reversing the motor wires so that the B unit runs the same as the A unit on analog. Then on the B unit change the setting in CV 29 (add 1) to reverse the direction on DCC.
Alan
 
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CV 29 is normally an even number. Add 1 to change the direction. If CV29 is an odd number, one must subtract 1. Do not add 1 unless you are sure it is an even number to start with!!! Even numbers are for 14/28 or 128 speed step modes, so adding 1 to an odd number can change the speed step!!
 
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