Copper Cap Refrigerator Magnets

For when you need no fooling, it's on there frig magnets.

My mother's birthday was coming up and while I had a nice present for her, I needed a 'stocking stuffer'. Something small and useful. The last time I was over there we were cooking and had a comedy of errors as about half the magnets on the refrigerator fell off during the evening. Most of them where the thin, free type you get in the mail or as a promo item.

Thus the idea for the making of the ultra powerful, no messing around refrigerator magnets with major pull and serious height to ease the gripping was born.

Step 1 Design Issues

The key to this whole thing is the magnets. I had some powerful, Neodymium (aka rare earth) magnets laying around from an old project and thought to use those. These have a pull over 10 times the ones she was currently using.

These magnets are so powerful (the ones I'm using have about a 5 to 6 pound pull force), I was concerned about getting a grip on them and then, having the grip object develop a glue failure. As you can see from my notes, if the glue strength is less than the magnet pull, then you will have a magnet stuck to the refrigerator and a nice grippy thing in your hand. Even if the glue is really good stuff, it will still stress the glue joint every time you pull it off the frig. Also, I wanted a grippy thing that was a bit taller then you normally see - My folks are not getting any younger and having to pinch down with the tips of their fingers to pull it off would not be a good thing.

So the answer was simple - copper pipe end caps. Available wherever you get your local plumbing supplies. Since the magnets I already had where 1/2" in diameter, I needed to get 1/2" end caps. 1/2" end caps actually have an inner diameter of about 5/8" (to fit over the 1/" pipe that has a 1/16" thick wall) so there would be a little wiggle room but not too much.

Comments

[Vissy]

Great!

Improvement:
Just fit a magnet to the inner diameter of the copper endcap, and use it the other way around. You can fill up the cap with more magnets or glue.

I like magnets, so I just use bare magnets.

[whamodyne]

Mr Slippy, Is that a solid copper slug, 10mm thick and 13mm in dia? I don't know if that would work. Using the end cap, the gap between the magnet and the frig is less than 2mm. Magnet strength goes down over distance, I would suspect it's a non-linear thing and thus, 10mm thick might be too much. I was also trying to do something with parts that folks can find at your general local store. Yeah, the magnets are not that normal but they have so many uses that getting more than you need for a project like this is not a bad thing.

[MisterSlippy]

Well, yeah, I was thinking of drilling out the slugs, putting the magnet in the open end. It wasn't a criticism, by any means....I'm known for suggesting completely unfeasible stuff a lot of the time ;-)

[Full Frontal Graphic]

Those 10 mm x 13 mm copper slugs should be useful for something though.

[cowscankill]

intresting

[MisterSlippy]

Cool instructable. You could save yourself having to buy copper caps by befriending somebody who makes copper busbars for large distribution boards. We punch 13mm dia holes in the 10mm thick copper bars to attach cables to...the copper nuggets that get punched out look like they'd be perfect for something like this. Hmmm....I should go get some strong magnets and do that very thing myself

[madebytrish]

I say bullet casings! also perfect for mom's birthday!

[lemonie]

Oh yes, shotgun shells, or smaller diameter (but less grip)? L