Cutting Magnets

[aonghus]

Anyone have any experience with cutting Samariam Cobalt (SmCo5) Magnets?

Chewed up some fine tooth jigsaw blades at low speed, hacksaw blade doesnt even make a dent.

Any help appreciated, I've already scoured the internet trying to find info, but to no avail.

thanks guys.

[LSRS7]

Maybe you could try a 4" diamond blade on an angle grinder like a tile blade.

[Bow Tie 67]

Just curious, what the heck are you working on?

[LSRS7]

Just curious, what the heck are you working on?
Yeah!

[Bow Tie 67]

Oh, I think I know " its for a Flux-capacitor! "

[Steve68]

Building a bad azz RC/slotcar motor!!!

[TonyHuntimer]

He's building a time machine!

Tony~

[aonghus]

Flux capacitor, thats it.... haha

I completley killed some expensive cobalt steel dewalt fine tooth jig saw blades with this stuff. It really doesnt look like it'd be as hard as it is, but jeez.

Good idea on the angle grinder, I don't know if I can be precise enough with that though, these things are $20 for a 3x1x1/4" sized piece. Can't afford to waste that much material, but screw it I'll give it a try on the morrow.

I'll post some pictures of what I'm working on, you surfer types might find it interesting but the rest of ya probobly wont give a hoot ;)

Thanks fellas

[chicane67]

I dont think it is possible to machine Samarium Cobalt magnets with conventional machining. Samarium Cobalt magnets can be abrasively machined with coolant (served to absorb heating and dust.) Without coolant, most rare earth magnets crack and chip by the heat produced during high speed cutting or grinding.

SmCo cannot be machined with conventional drilling, turning or milling processes, and must be ground before they are magnetized.

A tile saw with a diamond blade might work for a DIY project tho.

How big and what shape ??

[Blown353]

Tom made a good suggestion (as usual) in that you should try wet cutting with a diamond blade on either a tile saw or an angle grinder. You should be able to get pretty close with a good tile saw if you don't need to cut any intricate shapes. I can cut with about +/- 0.007" accuracy when cutting carbon fiber tensile/compressive lab samples using a diamond blade on a good tile saw after one or two test cuts to get the fence set.

Might also try waterjet cutting it although there might be a chance of chipping/breakout on the backside of the workpiece... shouldn't have any problem finding a waterjet shop down around San Diego.

[Steve68]

I want to see, magnetized longboard????

[aonghus]

Thanks Chicane & Blown,

Most of the granite companies down here that make counter-tops and kitchen surfaces have hi-pressure waterjet cutting inhouse, there are two of them literally three miles from my house. They are however, ungodly expensive. We'll see this is prototyping so high cost right now is to be expected.

Reciprocating-anything is not going to get the job done, I assume the cobalt content in this stuff is so hard that it just burns through whatever we've thrown at it. It sounds like a tile cutter will be the best bet. I've tried using motor oil with a bandsaw, oil to lube the blade as it contacted the magnet, that was an expensive and messy mistake.

The size I'm goin' for is 1/4" thick by 1" long and 1/4" wide. Its going to waste a lot of material, but I made just have to grinder/flap disc it. We'll see this afternoon when I am back from class.

[68sixspeed]

Can you get access to a surface grinder? That's about the only do-it-yourself bet I could see.

[aonghus]

I'm kind've embarrassed to ask, what is a surface grinder?

I'm sure I can find someone who has one or has access.

[trackrat79]

Just so you know you can buy rare earth cobalt magnets for r/c and slot car motors off the shelf. Some of the slot car magnets are broken up into multiple segments per side for better effitiancy. I don't think all the trouble you are going through is going to be worth the effort when you can just buy what you are trying to accomplish in a better quality.

Just the same I will ask some of the motor building guru's I know and ask them what is the best tool for cutting that kind of material.

[68sixspeed]

Sorry, surface grinder-- most machine shops, even school shops should have one- picture a grinding wheel similar to a bench grinder that can be adjusted for height, the table with the part is moved under it, typically held on a magnetic chuck, or a small vise can be held by the chuck. You take very small cuts a time, but it is the best way to cut hardenned materials and it gives a great finish.

http://www.harigproducts.com/Products3.html

-Dan