OO & N Gauge Railway Modelling, Videos & Tutorials from the Scottish Highlands
Welcome to the Strathpeffer Junction shop. UK shipping for OO Gauge ringfield adaptor kit orders is £2.99, irrespective of how many are purchased. We also ship to Ireland, mainland Europe, USA, Canada, Australia and New Zealand. Due to lockdown restrictions and our reliance on a mobile post office, parcel-sized orders are currently dispatched at Tuesday lunchtimes weekly, while letter-sized orders are dispatched twice weekly.
Due to recent VAT changes in the UK & EU, orders shipped to the EU will now be liable for Import VAT. How that charge is applied (as well as any admin fees) will vary from country to country, but in most cases you are likely to be asked to pay before the item is delivered to you. You can also buy our kits on eBay, where Import VAT is covered in the postage costs.
Due to a major water leak at home and subsequent related issues that were uncovered, we had to move out for a period of time while remedial works were carried out. We continue to prioritise orders to ensure they are despatched on time, but unfortunately haven't been able to respond to enquiries timeously. We're now back home and things are settling down, so we'll be clearing the enquiry backlog ASAP. Please accept our sincere apologise for these delays.
Hornby Ringfield Replacement 6V CD Motor & Adaptor Kit (HA2/12MM/Bo-Bo)
A brand new OO Gauge Hornby ringfield motor conversion kit for most Bo-Bo models, comprising:
a replacement 12mm thick 6Vdc high torque can motor,
computer-designed 3D-printed adaptor,
2 x 10-tooth gears (one spare),
a motor insulator,
retainer clips, and
a length of heat shrink tubing.
As with all of our Hornby kits, the conversion process can be fully reversible depending how you choose to install it, so the old ringfield (pancake) motor can be reinstalled at any time. The adaptor is also reusable, meaning the motor, adaptor and/or gear can be replaced with ease, if ever the need arises.
Our HA2 adaptor is designed for use with most Bo-Bo models. It should be compatible with a wide range of ringfield motor versions of the UK outline models, but we cannot guarantee compatibility with every model. The following list is provided for guidance – if there is any doubt, please contact us to discuss your requirements before placing an order.
Class 42 (Warships)
Class 43 (HST)
Advanced Passenger Train (APT)
Most Diesel Multiple Units (DMUs)
Not compatible with:
Hornby silver seal ringfield motors
Note: Hornby produced a wide range of ringfield models, some with subtle differences in design, and we have been unable to test every single variation in person. These lists are based on both physical testing of models and careful assessment of photographs for those we do not have access to. They are not exhaustive.
We have developed the adaptor to accommodate many of the different different casting details found on ringfield models. However, very occasionally light filing of the adaptor or the bogie may be required to perfect the fit.
On some particularly slim models or those with small bogies, it may occasionally be necessary to trim off 1-2mm from the end of the motor shaft in order to prevent it fouling on the bogie fascia. This can be done using a cutting disc on a Dremel, taking multiple small cuts and allowing the shaft to cool in between.
Please refer to our detailed installation booklet for specific fitting instructions.
★ For our Hornby10mm/Co-Co/Tender-Drive adaptors, please click here.
We can accept no liability or responsibility for any damage or injury occurring from the installation and use of our motor replacement kits. Installation requires modifications and the use of tools, some of which have the potential to damage you and/or you models, as well as other components and equipment. Users must not commence work unless they are confident that they have the skills and experience necessary to complete it successfully, and install these kits and undertake work to their models at their own risk.
1. Our replacement motors are high quality 6v DC motors designed for CD/DVD drives. The output from a DCC decoder or a DC controller can exceed their voltage rating depending on how hard hard the loco is being worked. Whilst our own tests (and those of many others before us) show that these motors are capable of handling voltages higher than their rating, in order to avoid motor burn-out, prolong motor life and achieve prototypical speeds, we recommend:
For DC/Analogue use, speeds are kept low manuallyvia the controller and a diode* voltage dropper should be considered in order to reduce voltage going to the motor (as outlined in the instructions);
For DCC use, decoders should have their CV5 value reduced (if available) and, particularly where CV5 adjustment is not available, a diode* voltage dropper should be considered in order to reduce voltage going to the motor (as outlined in the instructions). Some new decoders enable the top voltage sent to the motor to be set via CV57 and, where available, this should be used.
2. With all CD-style motor conversions, it is good practice to: i) maintain very high speeds for relatively short periods only, ii) keep running on steep inclines to a minimum, iii) avoid coupled up with excessively long rakes of coaches/wagons, and iv) where less robust 10mm motors are fitted, resist the temptation to fit additional weight to the loco.
3. It is recommended that locomotives fitted with our 3D printed adaptor kits are not run for more than an hour continuously; this is to prevent the motor temperature from exceeding the glass transition temperature of the plastic.
4. We recommend that locomotives fitted with can-style CD motors are:
Not run without a DCC decoder as ‘Locomotive 0’ on a DCC model railway layout (this is will lead to over-heating and rapidly ruin the motor), and
Not placed on the tracks whilst a high frequency track cleaner (such as the Gaugemaster HF-1/HF-2) is in operation. There have been some reports that the frequency can damage the motors, although it is not something that we have tested.
The following instruction manuals are available for this product:
Our upgrade kits can work really well on a DCC layout, however we strongly recommend that a decoder with CV2/CV5/CV6 functionality is fitted; a decoder with CV57 (motor voltage control) is even better. The functions will enable the starting voltage, top and mid speeds of the motor to be fine tuned (or, in the case of CV57, the voltage to be set) and make prototypical speeds more achievable. In most cases, it will also negate the need for a diode voltage dropper to be installed, although as with most decoder installations, you may still have to spend some time fine tuning CV values to get best possible performance.
Most decoders now have CV2/5/6 functionality as standard, but not all, so it’s wise to check the product manual or specification before buying. CV57 functionality is not yet widespread. Please note that Hornby’s R8249 decoder and their TTS Sound range are examples of decoders that do not have any of these functions onboard. Whilst it is still technically possible to use such decoders with our upgrade kits, it is unlikely that you will be able to achieve the same fine tuned speed characterises that you can with other decoders.
Without the option to alter CVs 2/5/6, you must: a) use a diode voltage dropper to reduce voltage going to the motor, and b) it is likely that you will then have to disable Back EMF and alter acceleration/deceleration CVs to suit. With non-sapphire Hornby decoders, you may also have to switch to motor algorithm 2 and alter the associated P and I parameters, and if it’s a TTS sound decoder, you will also have to change the sound notch triggers to ensure that the sound matches the speed as close as possible.
Altering CVs is almost always a case of trial and error and will be influenced significantly by the locomotive type, length of rake, track layout (incl. the number of inclines) and your own preferences for running characteristics. We strongly advise you to back up your decoder’s CV settings before making changes and to change one CV at a time, then test; changing too many CVs at a time may confuse the overall picture.
Using Hornby’s TTS decoders as an example, we have found the following CV values to work reasonably well for Hornby’s Class 37 (Un-refurbished) TTS decoder. The decoder was installed in a Lima Class 37 upgraded with our LA5 motor kit and our DD3 diode voltage dropper kit:
Configuration Variable (CV)
Configuration Variable (CV)
Note: Speeds steps should be set to 128 in order to provide fine low end control, however it is unlikely that you will ever wish increase speed steps beyond ~30 on the controller, otherwise the speed of the model will be far too fast. You will also have to learn to ‘drive’ the model and apply power carefully to get the train moving, backing off a little when the desired speed is achieved.
As is always the case with CVs, there are so many factors involved, you may well find that different TTS sound decoders, let alone different types of decoder, will required different CV settings and, as such, the values are offered simply as an example and may not suit your own scenario. Where diodes are used alongside a digital decoder, you will also have to learn to ‘drive’ the model and apply power carefully to get the train moving, backing off a little when the desired speed is achieved.
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