View Full Version : de-magnetizer
02-13-2005, 10:06 AM
I just bought a magnet for picking up chips, and in another thread someone mentioned getting a de-magnetizer to demagnetize the lathe bed. Where can I get a de-magnetizer and how much are they? Thanks! Joe S
02-13-2005, 02:12 PM
J & L Industrial or MSC has them. I like the small electric hand helds for around $60.
They are almost a must to have becuase calipers and other tools become magnatized. Chips jump and hang on when tools become magnatized.
02-13-2005, 09:15 PM
Check with Radio Shack or an electronics store. You may still be able to get a color TV degausing ring. The last time I saw one they were about $9. If I could find mine, I'd send you a pic. They're about 6-7" in diameter and have a button switch. Plug it in, push the button and move it around the lathe.
02-13-2005, 10:11 PM
I rather doubt any of the small ones will do a lot on the lathe bed.
Myself, I'd probably wrap several turns of heavy wire around the bed, and connect to a stepdown transformer. That, I'd power with a variable transformer such as a "variac", turning it up from zero to a "reasonable current" and back down. A clamp-on ammeter will show the current.
That ought to take care of it, if there is a problem.
The above, if you have the materials and knowlege, ought to work.
Just don't turn off power abruptly. That will magnetize, not de-magnetize.
For a general purpose demagnitizer find/buy/steal the biggest stepdown transformer you can. The sort used in an old unregulated 10 amp battery charger is perfect. These are usually cheap transformers without interlocked I/E laminations. Take the transformer apart and remove the block of "I" iron plates from the top. Short circuit the secondary winding. Wire it up with a foot switch. To use step on the switch and bring the object to be demagged close to the top of the xformer and slowly bring it away, then turn off the power.
Don't leave the xformer on for more than about 30 seconds or the magic smoke will come out.