Making a Test Board & Rolling Road for Analogue & DCC Model Locos

I’ve been doing an increasing number of DCC decoder installations and model locomotive repair jobs – both for myself and others – and setting up my tester and rolling road each and every time I needed them was becoming a bit tiresome (not to mention the rat’s nest of cables).

After pulling what’s left of my hair out for the final time, I decided to put together a small loco and decoder test board, incorporating my LokProgrammer and SPROG, as well as accommodating off-board control integration (DCC and DC/Analogue).

The board also features a rolling road, using DCC Concepts rolling road modules, and my own take on a means to permanently integrate them into a test set up and improve usability, using acrylic sheet, spacers and screws.

You can download a PDF version of the wiring diagram for the test board featured in the video via the link below:

This is only one way of approaching a decoder test board setup and there other examples out there. I do recommend that you consider something like this if you’re intending to do a lot of decoder installation and maintenance – it saves a lot of time and hassle!

CORRECTION: in the video, I mention the acrylic/perspex sheet as being 6mm when it is actually 4mm. A thickness of 6mm is likely to be too thick and may interfere with the wheel flanges.

Project Components

You can buy some components for this how-to project via the links below. Buying via Amazon affiliate links means I get a (very) small donation and helps to support the website and channel:

– DCC Concepts rolling road: https://amzn.to/2C1IB6t
– Red and black wire pack: https://amzn.to/2C1Infx
– Green 2-pin terminal plugs/sockets: https://amzn.to/2PiVfiW
– Peco straight track: https://amzn.to/2LGgPM7
– A4 clear acrylic sheet (4mm thick): https://amzn.to/2Cae1Yk
– M5x8mm black nylon spacer: https://amzn.to/2Pq7tX4
– A4 plywood 12mm: https://ebay.us/LGRLYW
– A4 plywood 3mm: https://amzn.to/2C03bE2
– ESU decoder tester: https://ebay.us/aBLzSi
– SPROG dcc module: http://www.sprog-dcc.co.uk
– Green power panel-mount socket/plug: https://ebay.us/nBLfXz
– DC power-style socket: https://ebay.us/nBLfXz
– 3 position, 2-pole switch: https://ebay.us/WyKD3b

3D Printer STL Files

If you’ve got a 3D printer, you can download STL file for the 3D-designed parts for free and print yourself a copy:

Switch box/enclosure: https://skfb.ly/6B6Cy
SPROG3 cradle: https://skfb.ly/6B6DY

Please note: If you choose to follow any of the steps or suggestions outlined in the video, you do so at your own risk and any damage or injury to yourself, your models, your equipment or others is your own responsibility. Your own test board wiring requirements will vary depending on the components that you use and also the specifics of your design. The diagram provided above is only a guide and you must work out your own wiring needs yourself to avoid costly damage to programmers, testers and decoders.

How to use a 21-pin decoder in a locomotive with an 8-pin socket

Whilst we crunch through a mound of unedited video filmed during June 2018, we thought we’d put out a short tutorial outlining one approach for making a custom 21-pin to 8-pin harness to enable the use of a 21-pin decoder in an 8-pin locomotive chassis.

The adaptor is simple to make and works well, but by its very nature, an 8-pin plug will not enable all functions of a 21-pin decoder to be used. This is unlikely to be an issue in most cases, as 8-pin chassis locos tend to have few built-in functions.

If used with a sound decoder, separate wires will need to be soldered to the adaptor for the speaker connections; the schematic below shows the relevant solder pads. Alternatively, in some cases, speaker wires can be soldered directly to the chip.

Download a free PDF file of the wiring diagram here:


Items required for this simple project are:

– MTC 21-pin breakout board (e.g. Laisdcc or ESU)
– 8-pin plug (pre-wired, if possible)
– Reel of decoder wire (for non-wired plugs)
– Soldering iron, solder & liquid flux
– Kapton tape or insulation tape
– Various tools, including: small side cutters, wire stripper and an exacto knife.

DCC Decoder Wiring Diagrams for Non-DCC Ready Locomotives

We’re working on a short tutorial looking at DCC decoder installation in older locomotives, such as Lima and Hornby, that are powered by ringfield/pancake-style motors.

To accompany the tutorial, we’ve produced a PDF containing a series of basic wiring diagrams to help with the installation process. They cover the more modern can-style motors (as found in Bachmann, Heljan, Dapol etc.) as well as the older ringfield ones (similar to those found in many Hornby and Lima models).

 

There’s also a basic diagram for directional lighting and a single Aux channel, such as the Aux 1/green wire available on most low/mid-range decoders, such as Hornby’s entry level R8249 8-pin variety.

The wiring principles would be the same for older ‘grain of wheat’ bulbs, although the resistor value would need to be altered to suit the bulb and track voltage.

You can download the PDF by clicking here.

Tutorial: TCS 21 Pin DCC Breakout Adaptor

In our last blog post, looked at the TCS-brand 21-pin breakout board, which can be used to permanent convert an 8-pin DCC decoder for use in a 21-pin chassis.

21 Pin DCC Breakout Adaptor Pinout Wiring Diagram

We’ve now put together a short YouTube video on how to carry out the modification, which you can watch below. We’ve also produced a wiring diagram to accompany the tutorial, which is available by clicking here.

TCS 21 Pin DCC Breakout Adaptor

We published a video in January 2018 describing how to convert an 8-pin Hornby TTS decoder for use in a 21-pin chassis.

In that video, we used a LaisDCC 21 to 8-pin adaptor, customised by removing the 8-pin socket, to allow the decoder to be plugged into a Bachmann Class 47.

While that method is still totally valid and remains the cheapest option (as of today’s prices), we have subsequently discovered a TCS-brand 21-pin breakout board which can be used for the same purpose.

These TCS adaptors are more expensive than the method outlined in our earlier video, but easier to use and require no real preparation. They only come in packs of five, however, and at about £20 per pack, if you only need one, they’re pricey.

We’ll probably do a quick video follow up in due course as we have another TTS chip to convert, but for the time being, as we’ve yet to find any instructions online, here’s a pin-out wiring diagram for the TCS 21-pin adaptor…

21 Pin DCC Breakout Adaptor Pinout Wiring Diagram