OO HO Model Railway NEM Magnetic Automatic Uncoupler V2 3D print model

When researching Automatic Uncouplers so I could create a magnetic coupler version for model trains, I realised how many different versions are used on the railways. From the research, it was quite obvious that the only real option was to create a generic-looking design that resembled the majority of Automatic Couplers. This V2 design has the Electrical Coupler below the Coupler Head.

Note: this is a representation of an automatic uncoupler and not actually a automatic uncoupler.

As this is designed to be a fuctional magnetic coupler the design is designed to be robust and strong and therefor is a representation of a Automatic Uncoupler and not a 100% accurate match, but in model form I hope it looks realistic.

To repesent the coupler head a little more accurate I have arranged the magnets to be fitted in two arrangements, one protruding and the other recessed.

These items are designed to be printed on a 3D Resin printer.

My biggest concern with this was the strength of a resin for something like a coupling, so the design was kept fairly simple to maximize the strength. I recommend you use ABS like resin or something similar, I used AnyCubic ABS Like Resin..

Magnets used: 2mm dia x 1mm thick

https://amzn.to/3WZoThF (Amazon) Associate Link

Resin used:

AnyCubic ABS Like Resin Pro 2 https://amzn.to/4dVZoEU (Amazon) Associate Link

Please be aware that 3D printed couplings will not be as strong as injected molded couplings, with using these you will probably need spares on hand in case of any break. With the ABS-like resin I have had minimal failures but nothing is perfect.

I have included a range of sizes as different rolling stock need different lengths (Please message me if you would like other sizes). These magnetic autocoupler comes in 8mm, 9mm, 10mm, 11mm and 12mm versions (Distances are measured from NEM socket to Magnet Face - see pictures).Magnets need to be glued in and you need to have the correct magnetic polarity for each magnet. This is very important for coupling together.The examples in the pictures were printed on an AnyCubic Proton M3 3D resin printer.For dimensional accuracy, I would recommend printing on a resin printer.As mentioned I used AnyCubic ABS Like Resin, I’m not an expert on what resin you should use.

Additional Info

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