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Good Morning,

I am in the middle of double powering a Lima 73 with two Blackbeetle Drives, unfortunately along the way I got bitten by the DCC bug and although I have fitted decoders to locos with one motor, Lima 20, Bachmann 20, I haven't been able to sum up the courage to chip the double power conversion. I have succesfully fitted a class 33 with one Blackbeetle drive and it is much better on DCC than on a feedback DC controller, I haven't been able to find any instructions or guidance on driving two power units from one decoder, I had planned using printed circuit board to get the power from the pickups to the motor, but I guess I can't if I need to wire in a decoder.

Any guidance would be appreciated.

Cheers
 

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It is quite simple to adda decoder to a double black beetle drive. As you have already fitted a decoder to a single BB you are no doubt aware of how to isolate the motor from the pick-ups.
You then need to connect both sets of pick-ups together, and connect both sets of motor terminals together, you should now have 4 wires connected to both bogies. The decoder can then be connected to these connections, just ensure you use a decoder with a decent amp rating, it doesn't have to be that big, 2amp peak 1.5amp continuous should do the trick.
 

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I am wanting to do a similar thing on a GMAM Garratt (see image in signature below). I'm looking at a large scale decoder to handle the peak power from the two motors.

I thought about using two smaller decoders and then setting up a multitraction (MTR) unit, but this would cause problems if I ever wanted to run the loco on another layout - parhaps at a show.
 

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Hi I know this is a old thread but I am looking for help in fitting a decoder to a twin motor loco. HOW did you get on with fitting and running your trains did all go well.
 

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If it is of any help, I have used two Black Beetles to power each of three LT EMUs I have built from kits. In each case, I have fitted both motors to one coach and used a TCS T1 decoder (not the smallest of decoders, by any means, but able to handle the power required by the two Beetles.

Wiring simply requires the two sets of pickups wired to red and black in their pairs (making sure that they come from the correct, same rail feed, regardless of which orientation the two Beetles are in), then the two sets of brushes wired to the orange and grey, again ensuring you wire the same sides of the motors so they both go in the same direction.

If you keep the circuit board, make sure the pickups and the brush feeds go to the right places in the circuit board so they connect to the correct wires in the DCC socket.

If using other motors (eg two of the Hornby type together), make sure you cut off any capacitors otherwise the results could be very unpredictable with BEMF turned on! I have not had to turn off the BEMF on the TCS decoders in the three trains I referred to before.
 

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I have used a pair of black beetles in an EMU and used a Zimo MX620 on each one. It works really well and having two decoders you retain the back EMF to give very good control.

I dismantled the beetles to remove the capacitors and attach the orange and grey wires to the motor, and connected the pickups of the two beetles together to give 8-wheel pickup. It works really well.

The only downside is that it has a scale top speed of 75mph rather than 100mph of the prototype, but I don't think that anyone will notice.
 
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