DCC Loco Conversions - 2 - Introduction

Suitability for DCC

All pre-DCC designed locos can be converted to DCC, whether it is worth doing or not is down to personal preference and the skill set you have available to tackle the conversion.

Before a conversion is started or even just plugging a decoder into a DCC Ready locomotive it is imperative that the loco runs well on DC and has no defects that will limit or prevent it functioning on DCC.

It must be stressed that fitting a decoder will not fix a faulty loco and a faulty loco may actually destroy a decoder.

There are a variety of defects or design issues which must be addressed before attempting to fit a decoder into a pre-DCC loco, and even some ‘Ready’ ones. What I present is not an exhaustive list as I learn more with each loco I convert, or attempt to convert for DCC running.

Before I dive into the meat of the subject let me define a few terms so we are all on the same track.

Definitions

1) DCC Sound Fitted

A DCC sound decoder and speaker(s) are fitted and the loco is ready run on DCC. I cannot comment any further on these as available sound effects do not appeal to me, I prefer to remember real locos from visits to preserved lines in the 70s and 80s, so I have not purchased or fitted any so far.

2) DCC Fitted

A basic decoder is fitted, usually of minimal specification from the loco manufacturer which typically has very limited functionality. Some I have found cannot be read, only written to and may have very limited basic speed control parameters if any.

Back EMF settings may not exist or be of poor performance. I discard them unless they are a recognised independent brand or nothing else will fit.

3) DCC Ready

Designed and built for DCC use, usually with a socket provided into which a small printed circuit board is already plugged so that the loco runs as a DC model out of the box.
That was not always the case, earlier it could also refer to a design which had all wheel pickup and substantial weight, both essential for reliable power transfer from track to decoder, but no socket.

4) No reference to DCC

Means that it was either a pre-DCC design or was not designed for fitting a DCC decoder e.g. the Bachmann Wickham trolley.

So, what are the options for decoder fitting if you do not wish to fit your own.

Fitting Services.

There are many decoder fitting services available provided in particular by the larger retailers who will supply the loco, a decoder and install it for you for a fixed fee.

However they have a blacklist of models that they consider impossible to fit with a decoder. By this they mean that it does not fit neatly into their decoder fitting service price list because the work required is beyond a certain time limit and skilled labour is expensive.

This will typically include those that require significant dismantling, or the use of tools to cut space for even a small decoder, in particular split chassis designs.

Also some DCC Ready locos can be difficult to dismantle. For example where there is much pipe work glued to both body and chassis which needs to be cut and repaired to allow removal of the body. BR Standard steam locos can be the worst for the sheer quantity of such pipe work all firmly glued in place!

Locomotives that are not DCC Ready may be converted by specialists at a price.

5) Skill Set

When it comes to converting pre-DCC locomotives yourself, you will need to be confident at using a soldering iron to hard wire (solder in) the wires from the decoder to the loco, potentially in confined spaces.

You need to be able to use a multi-meter to check motor current and motor brush isolation from track power.

Have the tools to cut the chassis where necessary.


Next, assessing the work required so you can decide, is it “Worth the Effort?”

Jim

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Images: Hornby J94, front underside of ballast weight cut away to fit a Digitrax DN136D decoder.