Lima Replacement Motor Kits – Troubleshooting Guidance

We have prepared a troubleshooting guide to address some of the rare, but potential issues that may be encountered when converting a Lima ringfield model over to CD-style motor. It is a live document, so do please check back from time to time.  Last updated: 16 April 2019.

Lima Ringfield Motor Adaptors – Out now!

We’re delighted to announce that the first batches of our UK outline Lima motor upgrade kits are now available to buy via the Strathpeffer Junction online shop.

These adaptors enable you to quickly replace aged ringfield motors in OO gauge models with CD-type motors, without the need for any messing around with glue or fiddly shaft alignment.

You simply remove the old motor and gear, pop the new motor into the adaptor, trim down the new gear and fit it onto the shaft, and then install the new assembly into the motor bogie. Everything is lined up and ready to go!

Each kit contains a motor, adaptor, two replacement gears (one spare) and some heat shrink. A set of detailed step-by-step instructions can be download from the website for those who need them, and a full installation video is available via the Strathpeffer Junction YouTube channel.

You can read all about them here:

What about Hornby?

Finishing touches are also being made to a Hornby ringfield adaptor – it’s a more complex design, but works equally as well on testing. There’s a little more testing to be done, but these should be ready in the Spring. Stay tuned…

Ringfield Motor Upgrade Using a 3D Printed Adaptor

In this video, we take a look at an alternative method for replacing the ringfield/pancake motor in older Lima and Hornby models with a brand new CD/DVD drive motor.

We’ve used glue and brass tube in earlier projects to support the new motor, and while it works well, it can be a fiddly process, it takes time and can be hard to reverse.

Using a computer-designed and 3D-printed adaptor, you can quickly and simply install and perfectly align a replacement DC motor.

If you ever needed to replace a component, or indeed wanted to reinstall the original ringfield motor, it’s entirely possible to do so. This is a non-invasive alternative!

This is a detailed, step-by-step video and you’ll probably want a cup of tea or coffee and a comfy chair. The methods used in this video are not necessarily the only way to do it, nor necessarily the best.

Some things to consider

The 10mm CD/DVD drive motor should work in most Lima models locomotives of the following OO gauge classes: 08, 09, 31, 37, 40, 47, 52, 59, 60, 66 and 92. Other models may be able to accommodate a 12mm motor, but you must check dimensions yourself first and the 3D printed part would have to be altered accordingly.

The replacement motor is a 12000rpm, 6V, 0.03A DC motor. The output from a DCC decoder or a DC controller can reach 12V DC (sometimes a little higher) at the top end. In order to avoid motor burn-out and prolong motor life:

1. Diodes should be used to reduce voltage (as shown in the video),
2. DCC decoders should have their CV5 value reduced (if available), and
3. Top speeds should be kept to a minimum and run at higher speeds for short periods only.

The PLA+ plastic filament used in the production of the adaptor has a glass transition temperature of 50°-60°C (the point at which it may begin to soften). Our trials showed the motor got up to about 47.6°C after an hour of constant running at medium-to-fast speeds.

Under normal ‘home’ use, it’s unlikely that the plastic will be adversely affected by motor temperature, however if the motor is used for very long periods or worked hard with a long rake etc., its temperature may begin to exceed the glass transition temperature of the plastic and it may begin to soften.

Please note: I’ve drawn upon ideas and suggestions from a range of sources, as well as implementing my own. If you choose to follow any of the steps outlined in this article or video, you do so at your own risk and any damage to yourself, your models or your equipment is your own responsibility.