Kit: MS480; SugarCurve6; 2x 470uF Tall Tantalums
Time to revisit the Class 56 with a view to fitting a sound decoder from the Zimo MS range... the approach is going to be
similar to the MX648, but let's see how the wiring is simplified, and how a stay-alive can be included.
With the chassis stripped down, we mill the platform for the speaker, making it as deep as possible, and also mill along the
top to make it easier to fit wiring.
The plastic clips cannot all be fitted, so we will be relying on some tape as well as the loco body itself to hold everything
together - sounds risky, but actually works very well in practise.
New wires are put on for the motor.
The wire from the lower terminal of the motor is secured with a dab of superglue, keeping it in the channel provided for it.
A quick test with the body on checks that everything is flush, and will hold together well.
Test fit our SugarCurve6 speaker with the body - seems to be comfortable. We could possibly even go with a 7, but let's not
push it, as there are wires to get in too! We also add red and black wires from the pickup tabs at either end, running the full
length - we'll solder the decoder's pickup wires to one end of these later.
Here is our MS480F - we'll be removing the sleeve completely and de-soldering all of the wires. We prefer the finer ESU decoder
wire for this job, and we'll solder each wire directly to the decoder as we progress.
Carefully expose the solder points for each end's lighting and replace those short wires with some longer pieces, using more
consistent colours - blue for common positive, white for headlights and yellow for the red tail lights.
We prepare the stay-alive, which will be 2x 470uF tall/narrow Tantalums. Some old resistor legs are soldered to the sides. Note
the white stripe on one side of the Tantalums - this denotes the positive side.
The Tantalums will eventually be sited at the very end of the chassis.
Since we have removed the factory PCB, we need to include some protective resistors for the lighting. We find an old factory
PCB and snip out a little bank of resistors. We only actually need 2 resistors (one for each end) in the model, as we won't be
adding any cab lights. Dapol make it very difficult to get into the cabs without breaking the lighting ducts, so we avoid the
risk in this model, though we will wire up the red lights to work independently of the headlights. We work out which size is
common on the resistor bank and put a blue wire that we go to common positive of the decoder.
We can solder on the positive wires from the lighting at each end to a resistor each too.
We add blue (positive) and grey (ground) wires to the Tantalums in preparation too.
The speaker is prepared by pinging out the terminals, bending them back and cutting them short. Some purple wire is soldered in
preparation. Doing this with the terminals allows the speaker to sit flat on the surface of the chassis.
The MS480 decoder is stripped of all its' wires and placed loosely in position on top of the chassis (insulated with tape, and
held with some double-sided tape).
We begin the process of soldering wires onto the decoder. Where possible, it is often easier to do all of the outer row of
pads first, as it gives easier access as you go.
With all wires soldered to the decoder, it is protected with some Kapton tape, as are the Tantalums.
Some more Kapton tape secures the components down and tidies the wiring. With the bogies inserted, we can now tests that it all
works as we expect.
Final adjustment of the pickup tabs, and check that the body sits flush on the frame, and we're all done!