4mm Magnetic couplings.

[LarryG]

I've been looking at the ads for magnetic couplings and while they bang on about a "new coupling system to replace the ugly tension-lock", there is never any talk of uncoupling. Simply pulling vehicles apart is frowned on (they have to be twisted)!

I lived in hopes there would be something between the rails that would momentarily de-magnetise the couplings, but there ain't.

Ah well.....

 

[paulc]

I've been looking at the ads for magnetic couplings and while they bang on about a "new coupling system to replace the ugly tension-lock", there is never any talk of uncoupling. Simply pulling vehicles apart is frowned on (they have to be twisted)!

I lived in hopes there would be something between the rails that would momentarily de-magnetise the couplings, but there ain't.

Ah well.....

Slide a bit of 10thou brass between them which has one edge thinned down . Seems to work for the 7mm version .

 

[Giles]

I did come up with a rising wheel chock (could be replaced with a simple pin to restrain an axle) which was a home-print mechanism for this very purpose. N20 gearmotor, one micro switch and the printed parts.

 

[LarryG]

I did come up with a rising wheel chock (could be replaced with a simple pin to restrain an axle) which was a home-print mechanism for this very purpose. N20 gearmotor, one micro switch and the printed parts.

Brilliant Giles. For simplicity, I have a number of soleniod activated uncoupler ramps for tension-lock couplings, so all I need do is remove the ramp and extend the support leg so that it restrains an axle. I just have to put up with the whopping bang...!

One question though : Are you using a readily available magnetic coupling such as from Hornby etc?

 

[Giles]

No, I printed some quite simply in PLA (although resin would do as well...) I experimented with different size magnets (given that I was looking at hauling two bogie coaches). I found that even 1mm dia were surprisingly useful, but 1.5mm were perfect for me - so far as I recall!
I've not tried any proprietary couplings at all, but one trusts they've tested all the permutations!,,