Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

okay so shot explanation I have a magnet ball that I want to use for my minis. now a magnet ball doesn't have the best halt on a flat surface so I wanted to cut some of it away at the bottom to have a flat spot where I can glue it on will that work
I know this like 8th grade science but i really don't wanna break my magnets

Depends on the magnet.

I'm not 100% sure, but I think the common neodym magnets (rare earth) are basically compressed magnet powder with a protection coating.
So you would destroy it by sawing it in half.

Bad idea.
I remember reading that the N-grade magnets are usually a magnetised powder core, glued into shape, and coated (as said).
I would not try cutting into them.
But, yours might be different.

I used balls for my jetbike mounts. I drilled a pit into the top of the flight rod, and there was more surface for the magnets to stick to.
Don't change the magnet, change the thing you want to glue it to. It will hold it in place better, too.
Or, buy a different shaped magnet, better for what you want to do.

Theoretically you should end up with two magnets if you saw it in half.

In practice you can make it less magnetic by knocking the little magnetic elements in the metal out of line (a strong magnet has them all aligned in the same direction).

In short, bad idea.

From K&J Magnetics

20. Can I cut, drill, or machine neodymium magnets?
The Neodymium Iron Boron material is very hard and brittle, so machining is difficult at best. The hardness of the material is RC46 on the Rockwell "C" scale, which is harder than commercially available drills and tooling, so these tools will heat up and become damaged if used on NdFeB material. Diamond tooling, EDM (Electrostatic Discharge Machines), and abrasives are the preferred methods for shaping neodymium magnet material. Machining of neodymium magnets should only be done by experienced machinists familiar with the risk and safety issues involved. The heat generated during machining can demagnetize the magnet and could cause it to catch fire posing a safety risk. The dry powder produced while machining is also very flammable and great care must be taken to avoid combustion of this material.

That sounds exciting! I say go for it and put the video on YouTube!

Keep the magnets whole and use some mild steel tube the same diameter as the magnet for the other side of the joint.

Or use concave magnets. EAsy to find on ebay or aliexpress.

If you're looking for a means to make a joint...mount the round however you want it and make sure it's gonna stay (which can be pretty easy with just glue and shims..) and get a receptacle piece that is ferromagnetic and about the right shape.. I suggest going to the bait&tackle store and look for nickel eye cones..

like so

http://www.montanafly.com/Picture%20-New/Materials/0-3-145-Brass-Cones---Black-Nickel---Large.jpg

Neither nickel nor brass are magnetic - so those particular ones won't be much use in a magnetic joint.

If you CAN find ferromagnetic ones, sure. but not those ones.

 chromedog wrote:
Neither nickel nor brass are magnetic - so those particular ones won't be much use in a magnetic joint.

If you CAN find ferromagnetic ones, sure. but not those ones.

I though nickel was magnetic.

Edit: Apparently it is, but it has specifics as to what kind of magnets work with it. NeFeBo REMs don't work well with them (most common magnets used by gamers).


It's used as a foundation coat for chromium plating, though, because chrome doesn't stick to bare steel, or brass.

I've unintentionally broken magnets in half and they still work fine.

People are correct in saying magnets are a powder, however that powder is compressed in to a solid block. They only turn back in to a powder if they start to corrode.

Now, I wouldn't trust the long term structural integrity of it, and since it exposes the delicate innards I'd make sure to coat the exposed area with epoxy to slow the inevitable corrosion, but it should still work.

How to actually break it? I dunno. I feel like trying to machine or cut it would probably be a bad idea. Just smashing it could work but then you can't really control the size of the shards (and wear appropriate safety protection and whatnot and for legal reasons I'm not advising you actually attempt it ).

Neodymium magnets are most often sintered (when a powder in compressed into a block), which makes machining more complex.
But the main problem is their very low Curie temperature, the temperature above which the magnet loses its magnetization. It varies with the magnet's grade, but can be as low as 80°C. Typical dry sanding will most likely result in local temperatures way above that. Maybe some careful wet sanding could work, but I don't know much about that.

Your best bet is probably to either drill a half-sphere hole to increase the contact surface area, as has been suggested (and drilling bits with a round point are very common), or use some type of epoxy putty to provide a good contact surface.

You could try just putting a decent scratch in to the magnet where you want it to break then drop it from a height in to a hard metal surface. I guess it depends how much you paid for the magnets, if they're cheap enough you can afford to destroy a few in your pursuit of a good break.

At work we bought a few larger high strength magnets and the guys in the workshop managed to break a couple just screwing around seeing how far away they could get them and still have them pull together, lol.

Just wrap a strip of something around it in a circle to increase the contact area at the gluing point of contact, like styrene rod, cut up plasticard or Green Stuff.

When gluing steel balls/ball bearings to models as pivot point, I did that by using a Dremel with a ball shaped carving head. That results in a perfect recess to drop the magnet ball into.

Alternatively, just drill a hole sized to the diameter of the magnet and make sure it isn't deeper than the magnet's radius.