Please ID this small, odd Chuck

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I have no idea, pls help.

That's not a chuck, it's called a 'hollow mill', generally used on turret lathes.

The four bars are cutters, and reduce the size of a rod to whatever they're set at.

Doc.

Check out the catalog from the Genesee Manufacturing company.

I acquired several of these (used) before I realized they weren't as convenient as I expected. In particular, with the positive-rake helical-bladed ones, you have to grind the blades for the desired cut diameter. The full range of adjustment of the helical (and yeah I realize they're actually lines developing a hyperboloid surface, not a true helix) hollow mill is not available with a fixed blade grind. The neutral-rake straight-bladed ones don't have that particular limitation, but they don't get any advantage of positive rake or shear.

From the number stamped on it, I suspect that's an older version of one of their two smallest models, taking 1/5 x 0.17" blades, the 18-L2 or the 14-AS, which have ranges of 1/8 to 1/4" and 1/4 to 3/8", respectively.

What they said - and going by the cotter bolt marks on the shank, that one looks like it been in and out of a good few turrets over the years..

We've been here before.....

digger doug said:

We've been here before.....

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Glad you have, this item is new to my shop. Lacking the skill to regrind this precisely, and lacking a present need for its intended function, I’ll try using it to hold tiny square workpieces that are too small for a 4-jaw lathe Chuck.

cannonmn said:

glad you have, this item is new to my shop. Lacking the skill to regrind this precisely, and lacking a present need for its intended function, i’ll try using it to hold tiny square workpieces that are too small for a 4-jaw lathe chuck.

Click to expand...

durrrrrrrrrrrrrrr?

Limy Sami said:

durrrrrrrrrrrrrrr?

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-Technically, the four cutters move in an out, similar to a drill chuck, using that knurled ring. So theoretically, I suppose, it could work sort of like a tiny 4-jaw.

However, the jaws are not able to be operated independently, and so there's zero provision for centering the work. The "jaws" are also offset from the center- they're cutters, after all- and so will only "grip" with the points.

All in all, not the best use of the tool, but considering basically no one uses hollow mills anymore these days, it's not like it'd be 'going to waste'.

Doc.