Bachmann 4MT

[Steve M]

Last week I acquired this model described as DCC ready. I believe this was one of Bachmann’s early efforts and came with very vague instructions for conversion.
After receiving some advice from other forum members this is how I did it.

First of all remove the body - as warned all these plastic pipes have to be carefully disconnected to allow the body to lift off. You can just see how little space there is above the cylinders to fit a decoder.

20181004_110645 by Steve Mumford, on Flickr


With the body off the size of hole for decoder is even more apparent. There ain’t much room in there.

20181004_111347 by Steve Mumford, on Flickr

I did try a direct fit decoder but found that it was 0.5mm too wide so initially I soldered a much smaller decoder to a spare plug. It worked well on the bench but when refitted, the plug was squeezed by the boiler - intermittent contact of the pins was the result.

20181004_115125 by Steve Mumford, on Flickr

In the end I ditched the plug and soldered the wires directly to the DCC socket. I was able to push out the firebox door from the inside which revealed a space just large enough for the decoder to fit behind the door. Refitted everything apart from the door for testing.

20181004_132823 by Steve Mumford, on Flickr


Once everything was proved to be working ok the firebox door went back on, then added a crew and some coal.
20181005_125811 by Steve Mumford, on Flickr

[Montfort]

Well done. Nice loco.

[Rog (RJ)]

It always amazes me how little space is allowed for decoder fitting. Just because they have fitted a socket doesn't make it DCC ready in my opinion.

[Mike Parkes]

One solution to DCC ready locos where their is little space is to remove the dcc socket and hard wire a decoder in place. Find its an approach that is quite useful on Hornby locos to get rid of the excessive amount of wiring they seem to fit and on a M7 for example a small decoder can as a result be fitted without needing any weight to be removed.

[Carl L]

Helpful replies as always, many thanks.

Carl

[Mr Bones]

Nice neat job.