Sound Install for 57 & 58 Class

Gerry Hopkins MMR

Fitting a sound decoder to brass or DJH versions of the above locos - with cam for 3 cylinder beat.

This page assumes the installer has installed sound decoders in steam locos before and knows all the basics about wiring.

This particular install uses the TCS WOW 101 decoder with Keep Alive unit. The sugar cube speaker is installed in the smoke box. Also required is the Soundtraxx Cam set.

Click on any image to enlarge

The 57 & 58 class locomotives were among the heaviest of locomotives in Australia with a 24-long-ton axle load and this along with their width restricted their sphere of operation.

They had the highest tractive effort of any conventional engines used in Australia and were of approximately equal capability to the 60 class Garratt locomotives.

The three cylinder design fitted to the class gave it a distinctive off-beat exhaust sound when climbing upgrade. This design was also fitted to the 58 class.
I always start the installs by fitting extra pick ups to the tender wheels.

This is done by adding a short piece of printted circuit board sleeper and the soldering apiece of 10 thou phospher bronze wire to touch the backs of the flanges as shown here.

I then use 36 gauge flexible wire to connect to the decoder
This photo shows how I mount the decoder and the KA2 in the tender. Black 1mm double sided tape is used to hold the units in place.

If you look closely, you can see one of the bi-colour (red/white) LEDs on the inside of the tender.

A 0.5mm fibre optic passes out through the rear marker light casting.

The heat shrink tube at the front of the tender acts as a guide forw the wires and also protects them from damage while you are working on the tender.
Here you can see the fibre optics sticking out through the lamp castings.

They will be cut to 1 mm length and then the soldering iron is held very close to "bell " the end of the fibre so that it locos like a lense.

The 2 LEDs are connected in series with a 5k resister between them.

If you are very keen, you can do the same on the back of the smoke box front - as shown. The headlight is a Surface Mount, Warm White LED.
The base plate has been removed and the rear set of drivers removed so that the cam may be fitted.

If the loco is a DJH kit, then the nut on the axle can be removed and the wheel taken off to aid the fitting of the cam.

The DJH has squared sholders on the axle so quartering is easy.

You can see the crank for the third cylinder in this shot.
This is the Soundtraxx Cam card, we use the 16 lobe cam for these locos. Cut the cam from the card- just around the outside of the circle.

Carefully drill a hole in the centre just big enough for the axle. Before gluing the cam in place as shown, remove the lobes as shown in the diagram below.

Glue the cam to the back of the wheel then paint around the flange with conductive paint or epozy (available from Jaycar). Leave for at least 24 hours to dry.
This is a diagram of the cam, remove the lobes shown in yellow - VERY CAREFULLY.

This may not be 100% correct for the prototype, but suits the position of the cranks in the models.
This is the under side of the chassis showing the extra pickups on the drivers.

At the rear of the chassis you see the extra piece of PCB for mounting the cam wiper.

The PCB and the wiper is supplied with the cam board.
Here is a close up of the cam wiper. I have some of these on a locos since 2001 - and they are still working well.
The tender is ready for attachment to the loco.

This decoder has 6 functions so there are plenty of options for the lighting.

You can see this loco on Youtube - 5808 Video