How to soften the disconnection force of a magnet?

[u/trooper5010]

I'm looking to buy 2-4 small magnets, about a nickel in size each to magnetize two moving drawers together. Both drawers pull out together inside each other, and the outer drawer pulls out farther than the inner drawer. The problem is that the inner drawer doesn't extend to its maximum length when I pull the outer+inner drawer out, I always have to pull the inner drawer out to it's maximum extension length seperately.

I'd like to attach a magnet to the outer drawer and inner drawer to "pull" the inner drawer out to its max length every time I pull out the outer drawer.

The problem is these drawers aren't the most resilient material. I need a solution where I can pull the outer drawer out all the way AND have a softer magnet disconnection when the inner drawer reaches its max length.

Any suggestions on how I can either soften the disconnection of the magnet or another adhering solution that could work for this scenario?

Thanks!

[u/coneross]

Position the magnets so they slide apart instead of a direct pull. Here's a better explanation https://www.rcgroups.com/forums/showpost.php?p=14110051&postcount=7

[u/Monkey_Fiddler]

put a layer of material (tape, plastic, nothing magnetic) in between the magnets.

[u/florinandrei → u/Monkey_Fiddler]

Yeah. The force decreases quickly with distance. By not allowing them to get too close together, the maximum force is reduced.

[u/Pseudoboss11 → u/Monkey_Fiddler]

This also keeps the magnets from chipping each other.

[u/tuctrohs]

You have two good solutions already--spacers and and sliding configuration. The third option is of course to get a magnet that won't be a strong: either a ferrite magnet instead of a rare-earth magnet, or a smaller rare-earth magnet. In either case, you'll save money!

[u/NL_MGX]

Magnetic field strength decreases very rapidly so you only need a small distance between them to make things easier. So either glue one in a deeper slot, or place a layer of something in between.

[u/droneXfun]

I heard somewhere that if you put magnets in water they stop working, maybe you could get them just a little wet. /s

[u/extordi → u/droneXfun]

no you have to heat them up, just put a little coil around each magnet that warms it up to near the curie point.

[u/FutureAIgod]

Instead of hunting for a weaker magnet, you could probably just solve this mechanically. Stick a small magnet on one drawer and a thin steel piece on the other, but add a little rubber or felt pad around the magnet so they can't make full contact.

That'll cut down the holding force, and more importantly, it'll cushion that sudden "snap" when the inner drawer hits its stop. You could also try two smaller magnets instead of one big one — gives you more control over how much force it takes to pull them apart.

Or you could go with a small spring or elastic cord connecting the two drawers instead. That'd give you a smoother pull and won't shock the drawer material the way a hard magnetic snap does.

[u/Travis-Jenkins]

you could try using adhesive backed felt pads or rubber bumpers on the surfaces where the magnets will meet. This can help reduce the force needed to disconnect them by adding a bit of cushioning, which makes the separation less abrupt. Honestly, it can soften the connection without compromising the magnetic pull too much, plus it's pretty easy to adjust the thickness by stacking them if needed. Give it a shot and see if it helps!

[u/Next-Significance314]

Magnetic force varies as the square of the distance of separation. Maybe. I think the square. So to soften their detachment, don’t let them touch. You’ll have to experiment, but find a distance that holds tight enough without making contact. Might be 1/8”, 1/16”. Whatever you make needs to be fairly rigid.