Hunt magnetitic couplings?

[Tim Blanchard]

Random question;   Has anyone tried using "Hunt magnetitic couplings" in a shunting-style operation? if so what kind of uncoupling device would be best? I'm not sure a magnet between the rails will work well, if any.

[Graeme Dunbar]

Random question;  Has anyone tried using "Hunt magnetitic couplings" in a shunting-style operation? if so what kind of uncoupling device would be best? I'm not sure a magnet between the rails will work well, if any.

Copied from my reply to your Tiny Layout thread:

Not personally, but a few members of our group use them. I'm not aware of any simple hands-off method of uncoupling (but see below) and they do it manually.

There is a post on NRRM online which relates to magnetic couplings but I can remember if they are Hunt ones. If I recall correctly it relies on a post coming up out of the baseboard behind an axle to hold a wagon and the locomotive pulling itself away. I assume it only works uncoupling locomotives as imagine a line of wagons could break anywhere between loco and fixed wagon.

[B.Meldon]

Magnetic couplings are not suitable for hands free shunting.
I use the standard H0e/009 loop and pin couplings with a ramp for uncoupling.
I get near 100% reliability, but every coupling has to be adjusted correctly to work well.

[Graeme Dunbar]

An off the wall idea just occurred to me. It would not work with Hunt couplings but possibly with some other design.

Some magnetic couplings (including Hunt if I remember correctly) have two magnets, one with a North pole facing out and the other with a South pole. This means stock can be placed either way round as the couplings are not 'handed'. If one of a pair of coupling was installed upside down or manufactured incorrectly then they would repel, not couple up.

Now, if the coupling shaft could rotate longitudinally along the axis of the track it was possible to twist the couplings so that the South pole of one was not longer adjacent to the North pole of the other coupling then they should no longer adhere. If they could be twisted far enough then they would repel.

Possibly some sort of lever might do the job, actuated by a ramp or similar or, if they magnets did not interact, perhaps even with an electromagnet.

Devising such a mechanism is left as an exercise for the reader, as they say....

Not exactly practical I imagine.

[Tim Blanchard]

Random question;  Has anyone tried using "Hunt magnetitic couplings" in a shunting-style operation? if so what kind of uncoupling device would be best? I'm not sure a magnet between the rails will work well, if any.

Copied from my reply to your Tiny Layout thread:

Not personally, but a few members of our group use them. I'm not aware of any simple hands-off method of uncoupling (but see below) and they do it manually.

There is a post on NRRM online which relates to magnetic couplings but I can remember if they are Hunt ones. If I recall correctly it relies on a post coming up out of the baseboard behind an axle to hold a wagon and the locomotive pulling itself away. I assume it only works uncoupling locomotives as imagine a line of wagons could break anywhere between loco and fixed wagon.

The pin through the baseboard sounds like the most likely solution. I suspect that an experimental track will be built soon to test that. At this time, all of my rolling stock has the Hunt couplings. I ordered a half-dozen packs of them when I finished buildingnsome kitsnthat had no couplings, so at this point, it wouldn't be easy to go to another standard.

[Graeme Dunbar]

A pin engaging with an axle should be fairly easy to set up on a test track, but I'm wondering if the video I saw was more sophisticated. I seem to remember quite a lot going on under the baseboard, so I'm wondering if it was was actually a pair of pins or claws (a bit like the contraptions in Peco stock boxes wedged against the axles) that spread apart.

I've had no luck in tracking down the video, but I didn't imagine it. I remember that the uncoupler was 3D printed and I'm sure it had a gear motor.

[Terry Mowles]

Is this the one you're thinking off?

First video is of it in action and second is of the mechanism.

https://www.youtube.com/watch?v=Sl03ig0LKw0

https://www.youtube.com/watch?v=Mf3d-Lq8QrQ&t=218s

[Graeme Dunbar]

Thanks. That's the one. I guess it may be possible to make a simple hand operated one or actuated by a point motor or electromagnet.

[Tim Blanchard]

I've seen this kind of setup for a "brake" on an incline where a shunting puzzle required a gravity run around a loco, but hadn't thought about it working to hold rolling stock while uncoupling.  that appears to be an interesting solution.