Metalworking!

Keyseat cutter. Square block , sticking above vise jaws, hole through block horizontally. Set screw to lock.

You mount the rod into a collet and collet block like these

You use one edge of the block to locate your work piece You cut a slot, rotate the block, 180 deg and cut the other slot.

Paul K. Dickman

If you are looking for new toys you could consider a small toolmaker's insert vise to clamp the part with both ends accessible.

The outside of the vise is precision ground to serve as reference surfaces when you clamp it in a larger vise. They are especially handy for milling at the precise angles you can set up with in an angle block kit:

jsw

"Paul K. Dickman" wrote in news: snipped-for-privacy@news1.newsguy.com:

I guess I wasn't clear enough. There is one slot on each end of the rod, not two slots on one end. I have a collet block, which is fine for cutting one end, but you have to remove the rod to cut the other end, and then you have the problem of aligning the rod to the block so the slots are at identical angles.

Doug White

"Jim Wilkins" wrote in news:khr603$k36$ snipped-for-privacy@dont-email.me:

Thanks. I actually have the poor man's version, which is a small Palmgren vise I trued up. That would work, but I think the Vee block is still the winner.

Doug White

I'd put a 1/4" piece of keystock at the bottom of a milling machine vise and flank it with two pieces of 3/16" keystock. Drop in the workpiece in the vise with the 1/4" slot fitting in the middle keystock. You should be able to clamp everything so that the workpiece slot is parallel to the vise jaws. (Upside-down screwdriver) Check for vertical perpendicularity with a machinist square.

Put it in a vee block.

Clamp rod in vise small enough that the ends stick out past the jaws (or clamp it down into a vee block to the table) with the long axis aligned with the long dimension of the mill table, and cut across each end with a keyseat cutter. No realignment or repositioning of the rod needed between cuts.

"Jim Wilkins" wrote in news:khr603$k36$ snipped-for-privacy@dont-email.me:

Thanks. I actually have the poor man's version, which is a small Palmgren vise I trued up. That would work, but I think the Vee block is still the winner.

Doug White

Remember Al expands on heating - and you will be hearing as you cut or mill on it - thereby cutting off or milling off more than you plan. The metal will have to be flooded as you cut - to keep cool and make the cut in the right place.

Al isn't all that easy to work with if you want a precision final. It is for the most part and alloys easy enough to cut, but precision is tough.

Mart> I have a project that requires a machining operation that I am puzzling

How about using square or hex stock, then turn it round after you make the groves.

Best Regards Tom.

Steve Walker wrote in news:fdednTSRkKuojNzMnZ2dnUVZ snipped-for-privacy@giganews.com:

If I have the right sized keyseat cutter, that would also work with the Vee block. I'll have to check my stash of cutters. It will have to be samll enoungh in diameter to only cut one side of the rim of the counterbore, but that could work.

Thanks.

Doug White

Martin Eastburn wrote in news:tfb0t.739332$ snipped-for-privacy@en-nntp-11.dc.easynews.com:

That's pretty much a general issue with holding tight tolerances in the stuff. My big concern is not that the depth & width of the slot are within a thousandth, but that the angle of the slots on each end is within a degree or better.

I've typically used my collet block for working on round stuff this size, but I should have a Vee block or small vise that will allow me to reposition the work without losing my reference.

Using a keyslot cutter has the advantage that with appropriate clamping, I don't have to move the workpiece at all.

Doug White

"azotic" wrote in news:khrfqa$bi$ snipped-for-privacy@speranza.aioe.org:

Ah! That would also work. Unnecessary in this case, but a possibility. The trick would be turning it into a smooth cylinder with both ends already finished. Flipping it around in a collet would invariably leave a small step, although in this case, that's not critical.

Thanks to everyone for theri input. I'll return the group now to its usually political wrangling.... :)

Doug White

Do any metals contract, on heating?

Christopher A. Young Learn more about Jesus

There are special formulations of Invar that have a slightly negative thermal coefficient. The common grades used in industry are close to zero.

Bizmuth expands on cooling.

Negative up to about the Curie temperature:-

Interesting that it's still negative down at liquid Nitrogen temperatures.

I think you need to specify a temperature range in which you're interested. IIRC Antimony expands slightly when it solidifies and that feature is useful in getting better definition in some white metal casting alloys like modern tin based pewter. Overall though it expands on heating over the broader temperature range.

Id use a shaper and a V block with a flat to ref to.

Particularly if the rod is longer than the lift of my mill.

Gunner

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