Magnetic chuck?

[Robotstar5]

I spotted this on FB marketplace, what's the round thing in the middle, some sort of magnetic lathe chuck?

 

[Maker]

Yep exactly that. I think I'd be a bit scared around it with anything but the lightest cuts in thick steel.

 

[dieselsamurai]

Ive often thought one would be handy but the image of something letting go at 1000rpm is not a good one !

 

[jsf55]

Off a cylindrical grinder ?

 

[Robotstar5]

Off a cylindrical grinder ?

Not sure, just something I spotted while perusing market place.

 

[Kram]

Mag chucks are often used for grinding where the forces are much lower. Perhaps used with a rotary table.
If using inna lathe or mill, the part may not fly off, but it doesnt take much to bump a part sideways and then a cutter would be scrap.

 

[awemawson]

Off a cylindrical grinder ?

Yes I have one for my J&S cylindrical grinder - don't use it much though.

 

[indykid]

Ive often thought one would be handy but the image of something letting go at 1000rpm is not a good one !

It's pretty benign. As @Maker says, you have to be aware of the holding power or lack thereof, but I usually hold the chuck in the 4 jaw and either stick a centre through the middle of the part so it can't run away too far, or make sure it's got plenty of engaged surface area and go extra careful. If it has the centre in and it grabs, it just climbs up the tool and slips on the face. I'm yet to have a part actually leave the face of the chuck, though it certainly makes you jump when it moves, but in stalling on the tool, it's already lost all its rotational inertia so it's only the centrifugal component that might cause it to fling.

The biggest issue is all the swarf sticks straight back to the chuck so the middle of a cut is like turning through a pan scourer, but it's nice to have for skimming washers and facing thin plate things.

 

[dieselsamurai]

The biggest issue is all the swarf sticks straight back to the chuck so the middle of a cut is like turning through a pan scourer, but it's nice to have for skimming washers and facing thin plate things.

I can definatley see a use for one skimming washers etc but forgot about the swarf issue

 

[Kram]

Thats what superglue is for.

 

[Fazerruss]

I can definatley see a use for one skimming washers etc but forgot about the swarf issue

I could have done with one last week for skimming aluminium washers but I think there is a floor in my plan somewhere

 

[6ply]

I can definatley see a use for one skimming washers etc but forgot about the swarf issue

You'd want one with a fine pole pitch for holding small parts/washers. I'm not sure whether there's a trade off between pitch and power?

5c emergency collets can be machined to hold small washers.

 

[awemawson]

I could have done with one last week for skimming aluminium washers but I think there is a floor in my plan somewhere

There might also be a flaw in your plan