Lima 42 Remotor + DCC

The old Lima 42 class diesel has been around my layouts for decades and I am not too proud to run it mixed in with all my more recent and highly detailed models. It ran well on DC and even better on DCC with a LokSound V4.0 decoder coupled with a replacement pancake motor and pickup on all wheels.

The motor shown in the top 2 photos was purchased on eBay as a specific replacement for the 42 class and other similar models. It satisfies the requirement of isolating the motor from the frame for DCC and runs well.

I always try to achieve pickup on all wheels or as many as possible. In this case it was easy. I added two small pieces of PCB to form solder pads. They are clearly visible attached to the two sideframe brackets with epoxy and carrying the RED flexible feed wire and the phosphor bronze pickup wires.

Note the holes shown in the bottom of the chassis to the top left. These are for the speaker shown in later photos.

A thicker piece of copper wire connects the 2 pads and one carries the p/bronze wires for 2 wheels and the other for 1. The photos show the setup.

The photos above and below show the decoder attached to the roof of the body shell with Blu Tack and small piece of strip board (Veroboad) used to carry the series resistors (1k – 1000Ω) for the front and for the rear headlights. Notice the “interrupts” cut into the tracks under the resistor. These were made with the tip of  a small drill. This isolates both ends of the strip. Normally the resistors would be mounted on the other side of the board but this method works  just as well

In the photo above I have removed most of the interior glazing except the sections for the front and rear windows. The portholes are glazed with Butyrate 15 thou strips held in place with tiny spots of Canopy Glue. [K & S Clear Plastic Sheet #1308]

In this model I used a 5mm (front) and 3mm (rear) yellow glow LEDs with ends of the LED filed flat and then polished. To avoid light appearing from other than the headlights, I carefully painted all but the front of the LED flat black.

I couldn’t find an appropriate and cheap socket to accept the 8pin decoder plug on the LokSound V4 so I made my own from a machined pin DIL (Dual In Line) IC (Integrated Circuit) 8 pin socket (eg Jaycar part# PI-6452 or on eBay).

The first step is to carefully cut the socket into 2 parts…

… as shown here.

Clean up the cut edges – the ones below need to be filed, but it’s not important as the correct spacing is achieved by gluing the IC socket back together on the smooth faces…

… as shown below with the prepared pair stuck in a blob of Blu Tack. Rough the surfaces a little and bond together with a spot of epoxy.

For this installation it suited me to bond the lead weight into the chassis with silastic and epoxy the prepared socket to the top of that. I have an old plug cut from another hard wired LokSound decoder that I can use as a guide to indicate which coloured wires need to be soldered to the rear of the new socket.
Note that installing the socket this way means that the off-centre plug can only go in one way around (good).

The mounting position of the speaker is shown above requiring some holes to be drilled in the bottom of the chassis. The speaker (which is not my preferred sugar cube type but was one of a number of spares I had in the workshop) is mounted just clear of the surface to allow sound to escape into the body shell. The speaker fits within the its housing but importantly, needs to be very carefully sealed into the housing. I use Canopy Glue on a toothpick to carefully seal every gap around the edge of the speaker, keeping it clear of the speaker cone. Also seal the spaces where the wires exit the housing – silastic may be better here.

This was the 25mm (1″) 4Ω  1.5Watt speaker and enclosure used for this project.

Here is a short video:

Published by

Rick Fletcher

Born in the steam era and developed an interest in railways when given a clockwork Hornby "set". Surrounded by steam when travelling to school (by train of course) and holidays were always by steam train as we had no car. How lucky was I?

Leave a Reply

Your email address will not be published. Required fields are marked *