Magnets For Spratt & Winkle Couplings

[BG John]

Can anyone suggest suitable permanent magnets for use with 4mm scale S&W couplings? I've got some genuine S&W ones, but they are thicker than my 1/8" cork underlay plus SMP sleepers, and I don't want to cut into the baseboard. I'd like something thinner, ideally 1/8" thick so I can fit them under the sleepers, but that are powerful enough to work.

[dasatcopthorne]

Can anyone suggest suitable permanent magnets for use with 4mm scale S&W couplings? I've got some genuine S&W ones, but they are thicker than my 1/8" cork underlay plus SMP sleepers, and I don't want to cut into the baseboard. I'd like something thinner, ideally 1/8" thick so I can fit them under the sleepers, but that are powerful enough to work.

Try Neodymium magnets. The downside is that they are very strong and can attract steel axles. So you will find yourself fitting very small ones. Search around and get a 'kit' of differing sizes to test.

 

The way I have gone is to fit strong ones but fitting them on the underside of the baseboard. (6mm + underlay).

 

Dave

[peter220950]

Can anyone suggest suitable permanent magnets for use with 4mm scale S&W couplings? I've got some genuine S&W ones, but they are thicker than my 1/8" cork underlay plus SMP sleepers, and I don't want to cut into the baseboard. I'd like something thinner, ideally 1/8" thick so I can fit them under the sleepers, but that are powerful enough to work.

 

Dave beat me to it, in 7mm I'm using the Neodymium ones, measuring the space I had, then finding something the right size on Ebay.

 

 

As you can see the pull from them is substantial. I put a pair spaced appropriately in the uncoupling positions.

 

 

If hacking out the baseboard is the objection to using deeper magnets, you could consider the round ones, they go down to about 1mm dia, so you could just drill a vertical hole between sleepers, that way you can set the depth of the magnet to get the approriate amout of 'pull'.

 

Peter

[BG John]

Try Neodymium magnets. The downside is that they are very strong and can attract steel axles. So you will find yourself fitting very small ones. Search around and get a 'kit' of differing sizes to test.

 

The way I have gone is to fit strong ones but fitting them on the underside of the baseboard. (6mm + underlay).

 

Dave

The layout is on a door, which is why I don't want to make holes in it. Things inserted in holes are likely to disappear inside. Magnets underneath would have to be very strong to work through 42mm + underlay, and everything metallic underneath the layout would end up attached to the bottom of it!

[BG John]

I found these, that are the same length, a bit wider, and thinner than the S&W ones, but am I being too backward thinking? I'm not sure of the pulling power of modern magnets, so would a row of small ones between the sleepers work just as well? They'd be easier to experiment with, and fix when I'm happy, but how powerful do they need to be?

[Spitfire2865]

If youre looking for magnets, check out supermagnetman.com

Tons of types and sizes, from absolutely ridiculous small to way too big.

[bourneagain]

Ben Alder very kindly supplied this link on a previous thread on this very subject, where he suggested he uses, very successfully 2-3mm thick magnets to uncouple S&W couplings

http://www.first4mag...king-magnets-t9 -

[dasatcopthorne]

Try spider magnets in Ebay. I think they may be cheaper.

 

Dave

[BG John]

I've gone mad and spent a whole £1.93 on some small 1mm thick  neowatsits on eBay. At that price I think I can just about afford to buy some different ones if my experiments fail! The S&W couplings arrived today, and the chemical blackener is in the post, so I can start trials fairly soon.

[jcm@gwr]

I must confess I've given up using chemical blacking on S&W couplings.

 

I found that it was too critical on the time in the solution, too short and it

hardly had an effect, too long and it would flake off!

 

Also, it made the surface rougher, therefore potentially making it slightly

less smooth to couple up.

 

You have use 2 solutions as well, 1 for the brass and 1 for the steel links,

it also doesn't take on any bits that you've got solder on!

 

I now use a permanent marker, it's quick, effective and the finish is smooth,

easing the hook to loop action.

[BG John]

Thanks Jeff. I bought a permanent marker some time ago to try, so I'll give both a go and see which works best.

[t-b-g]

I have used chemical blackening on such things with no problems in terms of roughness of finish. After application, I polish the metal with a small square (other shapes work just as well) of kitchen roll. It leaves a lovely smooth finish and if any blackening rubs off, it means that the metal wasn't clean enough and the polish plus a second application of liquid (plus another polish) does the trick.

[BG John]

I may do the first few with permanent marker, to get something running quickly, as at the moment I need some stock for track testing, and experimenting with type and placement of magnets. Then I'll try some chemical blackener and see which works best for me. I'm not good at thorough cleaning though, so may need to improve on it!

 

I'm planning to fit the 3mm scale delayed uncoupling type to my EM and 4mm broad gauge stock. I've also got an almost complete fret of the original 3mm type, so may try soldering a wire onto them for delayed uncoupling. I've also got loads of the original 4mm type, so may use those on my OO layout, again with delayed uncoupling added. Some of my EM stock has the original 4mm ones fitted, so they'll be coming off. I'm going to try the lower position on everything, which hadn't been invented when I fitted them decades ago.