# Help with Dual motor locomotive conversion



## tkruger (Jan 18, 2009)

To start yes I know there is a new version of this with DCC and sound etc. I have had this locomotive a long time, built it from discarded parts and that makes the value to me worth converting to DCC. 

I have an Athearn DD40 dual motor locomotive that I want to convert to run DCC. On the Digitrax web site there is a forum \ FAQ that suggest for converting dual motor locomotives use two decoders assigned the same address. This avoids any possibility of potentially overloading one of the decoders. I plan to use 2 NCE decoders. My question is how best to speed match these once they are installed? Is the below plan a solid one? Does anyone see any issue with this?

Mount each motor in one of two different single motor Athearn BB locomotives. Speed match these as two single motor units. Then remove the motors and mount in the DD40. Once in the DD40 assign the address to be identical for the two decoders.

BTW all of my conversions include cleaning the coms, wheels, full lube etc. The upside I see to the above plan is that in the process I end up with two single motor units ready to be converted also.


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## Cycleops (Dec 6, 2014)

As far as I can see you won't need to any speed matching if both decoders are programmed with the same address.


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## tkruger (Jan 18, 2009)

Cycleops said:


> As far as I can see you won't need to any speed matching if both decoders are programmed with the same address.


My concern was if one moter ran slightly better than the other. I have had no issues after years of DC running. I thought that since everything was getting fully dissembled, cleaned etc. it may be needed. 

Might just 'go for it' and see what happens. I have run it on the amp meter and with two motors running it is still under spec of one decoder with no load being pulled.. Do not want to chance that. These NCE ones have a 1.3 amp consistent and 2 amp stall rating.


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## /6 matt (Jul 7, 2015)

If yoy haven't had any speed match issues in DC operation I don't think you will have a problem.


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