Magnetic Uncoupling For Bachmann Couplings

[Graymee]

I've got a similar problem to Billy in a way, I'm just looking for the easiest option i guess
My track isn't yet fixed or ballasted but rather than knocking a channel into the baseboard, i was just going to remove some sleepers and cork to sit the magnets in? Figured with a bit of weathering once ballasted they wouldn't look too bad? I've seen some of the electromagnets on exhibition layouts (Kadee couplings) that are visible and don't look too bad, certainly better than Hornby ramps! But i guess that a couple of mins with the chisel to allow them to sink below the track would be the best bet. If i decide not to be lazy...

cheers

Graeme

[m mcdermott]

yes i think i,ll try going from underboard and drill after pilot hole from top thanks for tips ,billy

[Andrew Clarkson]

I too found this thread by accident searching Google for Kadee uncouplers, and what you've done looks great - I have a 20mm board to overcome, plus ballasted track, however, I'm going to try find a couple of old speaker magnets from a demic stereo or TV and see if I can get a reaction between the rails and take it from there - GREAT solution there!

[edwardholmes91]

Wow, this is great. I am still not getting how the magnets make the couplings push up though and how even when they do you can control when it does it. What is to stop them coming undone when you go over them as slow speeds? I am confused

I was thinking about electromagnets and using a change in current to attract or repel the couplings? Well... it wouldn't even need to be that I suppose, just repel I guess or no current when not wanting the couplings to undo. The only problem I come to then is I need another small magnet on the couplings that it can repel. And how can I go about doing this?

[Brianetta]

holmedwa04, the magnets don't push, they pull. They're pulling on the opposite side of the pivot to the coupler itself, and so the coupler rotates up as the staple rotates down. Like the regular spring loaded decouplers you can buy, the magnet causes an upward force on the coupling hook. When the train is being pushed, the hooks open and close again. When the train is being pulled, the coupling hooks remain down because they have fitted into a groove under the coupling bar. This is by design, and is why they're called tension lock couplings. They lock when under tension.

If the wagons are bouncing against each other (common at slow speeds), and especially when decelerating, there can be accidental decouplings on both this magnetic type and a normal spring type decoupler, because the couplings are not under tension. There probably isn't any trivial way to fix that problem with a mechanism that uses a fixed force of any kind.

[edwardholmes91]

Ah yes. I see the logic in it now!

I think a nice big electromagnet would be nice though. Then just a simple switch turn it on and when you drive over the coaches uncouple and turn it off and nothing happens.

[ElDavo]

For those that need to retrofit magnets to track that is already ballasted, try searching for Neodymium magnets on fleabay. I have used 15mm round by 2mm thick on Cramdin Yard and they work through my 6mm MDF baseboard and the ballasting. A bit tricky to position but not that difficult. These magnets are pretty cheap and readily available. Beware they are tricky little devils to handle as they are very strong! I have simple glued them to the underside of the baseboard with a hot glue gun. If I was doing it again I might get slightly larger versions (both diameter and thickness) to make vehicle positioning a little less precise.

If anyone is interested I'll try and get some photos underneath the layout.

Cheers
Dave

[mark22c]

i bought some neodymium magnets from fleabay the other day for this. i got 20x 6mm by 6mm cylindrical ones for about £2 inc p+p thought i could drill a 6mm hole between the sleepers and glue them in and ballast over them, you should hardly notice them. loads of differant size magnets on fleabay that should fit any base board even if you have allready laid and ballasted the track its easily doable...

[Brianetta]

I think a nice big electromagnet would be nice though. Then just a simple switch turn it on and when you drive over the coaches uncouple and turn it off and nothing happens.

Easier and cheaper would be a movable magnet. Attach it to a dowel fed through screw-in eyes under the baseboard, and simply push or pull the dowel to slide the magnet under the track or not. The same magnet could even serve to uncouple wagons on adjacent tracks just by moving it further. Parking it between tracks will put it out of effect's reach.

Incidentally, large and powerful neodymiums can be found, in pairs, inside hard drives. If you're dismantling a hard drive, don't let these magnets come together and pinch your skin. It hurts.

[Doddsy2978]

It may be possible, with care, to counterbore the board from below might get the magnet closer to the rails. I am gonna experiment with Peco N Gauge couplings - I can't see why they wont work!

Cheers

Ian

[edwardholmes91]

I think a nice big electromagnet would be nice though. Then just a simple switch turn it on and when you drive over the coaches uncouple and turn it off and nothing happens.

Easier and cheaper would be a movable magnet. Attach it to a dowel fed through screw-in eyes under the baseboard, and simply push or pull the dowel to slide the magnet under the track or not. The same magnet could even serve to uncouple wagons on adjacent tracks just by moving it further. Parking it between tracks will put it out of effect's reach.

Incidentally, large and powerful neodymiums can be found, in pairs, inside hard drives. If you're dismantling a hard drive, don't let these magnets come together and pinch your skin. It hurts.

What an excelling idea! I never realised that you could get them out of disk drives! I have loads of them lying around that I am intending to dismantle anyway so I will have to look out for them. I have had a play with some neodium magnets at school and they are extremely powerful. If you let them snap together they can easily shatter I think.

[stevebar]

A big thumbs up for Brian for this brilliantly simple and effective idea.

There's been lots of discussion about magnets/electromagnets and above board/undertrack or underboard/drill through, but it's the idea of gluing a little bit of wire to the coupling that makes it work.

I'd spent ages trying to figure out how to have enough decouplers, working reliably and cheaply, to be able to decouple pretty much wherever I want to.

This does it for me, for around 50p a decoupler.

Fortunately I'm at the stage of having all my track loosely pinned before wiring and ballasting, so it's easy to just lift, cut slots in the cork underlay and repin the track.

Once again. Thanks for that one Brian.

[son of triangman]

Brian's idea is very effective, well done Brian. For siding use it would be very effective in place of the old Tri-ang/Hornby ramps which look terrible. What affect does the magentisim have on loco motor magents I wonder?

[GeoFF03]

What affect does the magentisim have on loco motor magents I wonder?

Since magnets are used in the operation of Kadee, sprat & winkle and others, no doubt we'd have heard if there were efects to the motor magnets.

[son of triangman]

Just a thought, how about electromagnetic uncouplers?