Thursday, March 24, 2011

Hobby Innovation - Slotted Magnets, Part II

Alright, well there's been some progress on my quest to achieve "non-spinny magnetized arms" as described in this post.

I sent a follow-up email to K&J Magnetic:

As a followup, I understand that the magnet material itself would be too brittle to machine these shapes into easily. However I also understand that many magnets have nickel cladding around them. A slight thickening of the cladding on the top and bottom of the cylinder would allow you to machine those shapes into the nickel. 

Subsequently I received a reply email from K&J Magnetics, which follows:

The nickel plating (actually a three layer nickel-copper-nickel plating) is applied by an electrolytic process in a thin, even layer.  It's not really practical/possible to add a super thick layer selectively (on only one surface).

You are moving towards describing a solution, though.  With neodymium magnets, it usually makes sense to move the complicated parts to another part.  For example, one could glue on the extra feature you're talking about.

Best Regards,

Michael Paul
K&J Magnetics, Inc.

Well, that's certainly understandable. I didn't realize they were using an electro-plating process (though it certainly makes sense as to why they would). Michael might not be aware of some of the more cutting edge electrolytic manufacturing processes out there but I suspect they won't be applying those to my hobby magnets anytime soon...
So I thought about this and thought about this. Images of plastic sprues with custom molded plastic "caps" to attach to the magnets were going through my mind. Thoughts of different ways to fabricate such a thing left me groaning (in frustration, sickos).

But this morning I hit upon what I think is a solution.

Necessary materials:

-Relatively thick (maybe 1.5 mm thick, maybe a bit thinner) plasticard.

-Relatively heavy duty hole punch of the same diameter as the magnet I intend to use).

-A hobby saw (these have VERY fine blades and are designed to make precise cuts in plastic without deforming it).

All of these things I have or can get access to.

The plan: 

1) Punch out a simple plastic circle.

2) Cut the circle down the center, giving me two "half moon" shapes.

3) Attach one half moon to one magnet surface, and the other half moon to the opposite magnet's surface.

4) When you put the magnets together, the moons will line up to form a circle, and prevent rotation.


Anyone see any problems? Anyone want to test it out? It will be a bit before I get to it (I plan on using it for my Swarmlord/Hive Tyrant magnetizing project). Pictures will be posted and gratitude freely given for anyone who tests it.