Precision magnets!

[projectnut]

Thank you all!

And also thanks for the ideas on the demagnetiser. I still hope to find an old industrial one for cheap.



I like it! I used it today on the lathe and its fine there too

Way more reliable than the Noga I had before.



I thought about that for the next ones I make, but I suspect that it will be a pain to assemble

I might ditch the pins and do some other form of joinery...I am looking towards the woodworkers already. Something with tounge and grove maybe.

Demagnetizers seem to show up all the time in the Business and Industrial section of e bay. I bought a 10' x 10" plate one a couple years ago for less than $30.00. It doesn't get used often, but it's worth every penny when it's needed.

[Evan]

Eh? How come we never had any such excitement when bulk erasing stacks of 1" audio mag tapes all on aluminium spools?

Not a powerful enough demagnetizer. Trust me, it can happen. I have done it with the one I built with a very large transformer. Induced electric current in a conductor always produces a magnetic field 180 degrees out of phase. See Faraday's Law of Induction.

When I placed a 2 inch disk of aluminum on it and hit the power it would fire it good enough to hit the ceiling. The bigger and heavier the aluminum part the more force it produces. The reason it happens is because it isn't magnetic but is a very good conductor.

[Andre3127]

These blocks are awsome! I have some magnets left from my 4th axis/lathe headstock direct drive servo motor so I might give a try. Problem is they are quite big so I think that the block would be too strong, plus I don't have a surface grinder yet.

The demagnetizer would be awsome. All my tools are becoming magnetized and I'm getting really tired. The one that gives me more headaches is my mitutoyo carliper, almost imposible to work with it now.

You could just mill them, lap them (with a non-magnetic lap) or scrape them with a carbide scraper blade.

[pinstripe]

When I placed a 2 inch disk of aluminum on it and hit the power it would fire it good enough to hit the ceiling. The bigger and heavier the aluminum part the more force it produces. The reason it happens is because it isn't magnetic but is a very good conductor.

A company I worked for had a decent demagnetizer. Not sure how strong, but it was used to erase VHS tapes that failed QC. I ran some faulty hard drives through it once. They didn't hit the ceiling, but they definitely left the conveyor. Probably bounced a few centimetres. Pretty loud as they thumped against the belt.

[Swarfer]

Induced electric current in a conductor always produces a magnetic field 180 degrees out of phase. See Faraday's Law of Induction.

Ah, thanks. Definitely worth remembering.

[iMisspell]

Stumbled across this... Nice job.

http://hackaday.com/2016/11/02/magnets-for-a-machinist/

.....

[becksmachine]

Interesting project Stefan. What was your conclusion on the Fog Buster? It wasn't clear if you were using it by the end of the video.
Would you consider one for your mill or lathe?

I like it! I used it today on the lathe and its fine there too

Way more reliable than the Noga I had before.

Beautiful work Stefang, on both the tool and video.

Another vote for the Fog Buster, far superior to other mist systems IMO.

I use mine mostly for drilling, but they will work anywhere and create much less unwanted mist in the process.

Dave

[sarge41]

This is a bit aside of the OP's subject, but I once used a pair of Starrett 3657aa magnetic bases and match ground them on parallel sides (skimmed) and created nice magnetic parallels. Not as pretty as the OP's, but very usable.

Sarge