Kit: MS490; SugarCurve6; 2x 470uF Flat Tantalums
We revisit Dapol's Western again, this time with a view to fitting a Zimo MS sound decoder.
This model happens to have a Next18 DCC socket instead of a 6pin, but the chassis and space available is identical, so our
approach will be the same no matter.
As it turns out, the tiny MS590 sound decoder will actually plug in and fits snuggly in front of the lighting socket. The
problem is that there is nowhere for a speaker, so this approach will not help - we have to make some space!
We begin the process of stripping it down ready for some milling...
Milling complete - we have been quite extreme, taking as much as we dare off the whole of the top, which will help with fitting
wires in, and creating a platform for the narrow MS490 sound decoder to sit on top. The original platform where the model's PCB
was has a good space for a SugarCurve speaker, so not too much to do there.
Clean the chassis halves of all debris from milling and we are ready to start reassembly. Fresh wires to the motor need to be
added before reassembly.
File flat the plastic bracket for the motor, so that the platform for our decoder is totally flat.
So we begin the process of wiring everything up. We generally prefer to remove the decoder's original wires and solder fresh
wires direct to the appropriate pads. This avoids unnecessary joins and allows us to get wire lengths closer to optimal. Our
stay-alive will be a pair of 470uF Flat Tantalums, which can be conneted directly to dedicated stay-alive pads on the decoder.
Add wires to the Tantalums (note the white stripe on one edge which denotes the positive side). A little Kapton tape to
protect, then secure with some double-sided sticky tape on the chassis end - perfect fit!
We include a pair of resistors to protect the LEDs. and replace the original lighting wires with some fresh ESU decoder wire in
more understandable colours. We'll have independent reds from the headcodes, so will use FA1 and FA2 outputs for these (green
and brown wires shown).
All wires are now connected, so we can put the frame back on, insert the bogies and test that everything works.
Finally apply some protective Kapton tape to the decoder, and some more to secure components and neaten the wiring.
It is a tight fit, but does go on, and looks great. Performance is great, especially with the little bit of stay-alive. We
didn't bother trying to add cab lights to this model, as Dapol make it very hard to get into the cabs without breaking the
lighting ducts. Our final touch is to insert some suitable headcodes, and we're off!