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:

“Charles” Gets a Decoder

A project with a difference – PART 2.
A friend has a Fleischmann™ type 4028 0-6-0 Steam Locomotive which he would like to use as a “proving” loco for his under-construction Wolgan Valley layout. It’s a sort of a recycling exercise. This is the next exciting episode – Charles gets a decoder!

The decoder is a LokSound V4.0 running the ESU sound file: 54413-LSV4.0-Dampf-BR80-R5      It sounds like this:

Very Germanic!! But it will be OK for the purpose, assuming that the NSWGR may not have bothered changing the whistle.

This is where the LokSound decoder will reside. For a tank engine, the Fleischmann 0-6-0 has plenty of room. After a little testing, it was least obtrusive in the cab roof and is held in place with Blu Tack.

There are other things to do with DCC sound installs one of which is the Speaker and more details will follow. This is one is my favourite Sugar Cube speakers in my favourite mounting area – the smokebox. That way the sound comes from the right part of the loco! [post coming on fitting a sugar cube into the smokebox of a brass 30T class loco]

The motor, especially in this ringfield type requires special attention to make sure that it is isolated from the frame.
There is excellent technical advice on this in an article I obtained on the “All Aboard” Mittagong website – except it doesn’t seem to be there any more. The original PDF file I downloaded from “All Aboard” is however available HERE.

The replacement Isolated Motor Shield is shown below fitted to the mechanism. It is sold as Fleischmann replacement part # 50 4730 and is available from All Aboard as a spare part (not shown on the web site).

Here you can see the wiring from the decoder to the motor – Orange and Grey to the motor and Red and Black to the track pickups (loco frame and wheels). Some other wiring is visible and is described below.

The decoder has a number of unused function wires and they are held captive by the (yellow) kapton tape. Two extra simple PCBs are also visible. Simple PCBs are described in THIS POST.
The one on the LEFT has 4 strips – 2 carry the brown wires to the speaker (in the smokebox) and 2 carry the wires to the front headlight.  The bottom strip can be seen to have a connection via a resistor to the WHITE function wire (headlight).

The value of the resistor is 3k3 (3,300Ω) indicated more clearly on the board to the RIGHT where the colour code is ORANGE, ORANGE, BLACK, BROWN, BROWN which is 3 3 0 (1 nought) and (1 percent tolerance) ie 3300 Ohms ± 1%  This value is higher than most people use but it provides a more prototypical yellow glow in the Warm White LED.

Image© courtesy eBay

Incidentally the LED is a tiny pre-wired device where the LED size is 1mm x 0.5mm and is available in Warm White, Bright White, Red and Green & available on eBay for ridiculous prices.

Sold as: Pre-soldered micro Litz wired leads Warm White SMD LED 0402

They will fit into the smallest headlights on a loco but must be handled with care.

The pcb to the RIGHT is shown in detail below and feeds the rear headlight and the 3k3 resistor is on one strip which has been interrupted under the resistor making 2 isolated pads.

The common wire is BLUE and feeds to both small PCBs. The YELLOW wire is the function output to the rear headlight.

The speaker used is a Sugar Cube which measures 12mm x 14mm x 5.4mm thick (bare). This is one being prepared in an enclosure.The following speaker is ready to go in:More about speakers in a separate Post.
And to save you scrolling back up – the photo below is repeated and shows the sugar cube sitting in the Smokebox and under the chimney which has been drilled out so that the sound is coming from the front of the loco both top and bottom. I will go to any length to try to get the speaker OUT of the tender and into a more realistic place. You can detect the difference in a passing HO loco.

If the speaker enclosure is mounted on the chassis it is inconvenient to wire as a plug and socket arrangement would be needed. Instead, I have located the enclosure to the inside of the body shell by the simple of expedient of a blob of Blu Tack in the top of the body which “grabs” the speaker when you assemble the two parts.  [Yes, I know … there should be a plug connecting the decoder and the motor/pickups but I got lazy]

Here is another loco with homemade plugs and sockets so that the body mounted  speaker can be separated from the chassis:The 2 brown speaker wires from the decoder are connected to the speaker via a 2 pin plug. The body and chassis can then be separated. This loco is a 73 class shunter.

The next episode will cover painting into NSWGR “colours” but in the meantime, here is a preview of “Charles” making some noise! Deutschland Über alles!