My Bridgeport has suddenly become magnetized

[jmarkwolf]

Small chips and fuzz are becoming quite magnetized and radiate outwards from the end mill when the spindle is stopped. Tools left on the bed, like my dial indicator, have become magnetized and picking up chips, etc, etc.

Anybody know the reason and the fix?

 

[JimDawson]

Your magnetic personality maybe?

Honestly I have no idea how that can happen, but I picked up my digital calipers today and they were magnetized. I haven't seen that for a long time.

I can demagnetize the calipers, but an entire milling machine is another story. You would need a big degaussing coil. If you have an AC arc welder and a bunch of welding cable you could use that. The coil would have to go around the machine and you would have to be able to move the coil over the top to the bottom a few times. This is the way they degauss ships.

If anyone has any ideas here, please jump in.

 

[mikey]

Your magnetic personality maybe?

Cracked me up!

 

[Tozguy]

A wild guess:

Tool is rubbing instead of cutting. Small dusty chips are not kosher.
Sharpen tool, different style end mill, and recheck speed, feed and d.o.c. against recommended ones.

 

[rgray]

Earth ground it? Ground in electrical system missing contact?

 

[12bolts]

Are the tools magnetized, or is it the chips? Get a nice piece of (known to be non magnetized) iron, and see if the chips are attracted to it.

Cheers Phil

 

[jmarkwolf]

Are the tools magnetized, or is it the chips? Get a nice piece of (known to be non magnetized) iron, and see if the chips are attracted to it.
Cheers Phil

Goodquestion.

Thanks Phil, and everyone.

 

[jmarkwolf]

OP here.

After some repose, I think that Phil's suggestion is correct.

The dial caliper seems to be no more magnetic than normal after a good wiping, so I think it is just the chips becoming magnetized.

When this magnetization occurred, I was making a set of t-nuts for my new rotary table, and doing some side milling. Perhaps my feeds and speeds were wrong for the task.