Mill tooling

[earlgo]

Additional to Harold's and Steve's comments about a short drill chuck shank, I have edge finders in both 3/8" and 1/2" so I can change from a 1/2" em to a drill chuck to an edge finder without too many Anglo-Saxon mutterings. In my instance I use tool holders because they are shorter and smaller in diameter than the R8 collet chuck. Bear in mind I have a small horizontal mill with a #40NMTB spindle socket, and not a lot of in and out motion. (My Z-axis is a Y-axis on a vertical mill.) By the time I get a vise mounted and a collet chuck inserted, half of the Z is gone.
--earlgo

[John Hasler]

Harold writes:
One thing that a collet allows is the end mill to move under the cut. Holders, assuming you've tightened
the screws properly, avoid that problem. However, the problem is far more imagined than it is truthful, not
that it can't happen. Here's the deal. So long as you understand what "tight enough" means on the
machine drawbar, you can hold end mills adequately secured with a collet, even under a heavy cut.

I get good results using MT3 collets. Keeping the shanks of the cutters and the insides of the collets clean and totally free of oil is essential: I wipe them with acetone. I lightly lubricate the outside of the collet with anti-sieze. I also do something that will horrify most: I use fine emery cloth to lightly sand tool shanks, the insides and outsides of collets, and the inside of the mill taper longitudinally.

[SteveM]

I also do something that will horrify most: I use fine emery cloth to lightly sand tool shanks, the insides and outsides of collets, and the inside of the mill taper longitudinally.

Get the smelling salts!

[Harold_V]

I'm in agreement with the smelling salts. Here's why.
Anything that is abrasive will remove metal. That's the chief reason I never advise one to stone off a mill table, choosing a dull file instead.

While the amount of metal removed when polishing with fine cloth is extremely small, metal is removed, and it isn't indiscriminate. After a prolonged period of time it will be measurable and most likely destructive to some degree. I wouldn't do it personally unless there's a very good reason to do so.

Keep tapers clean and dry from oil and they'll perform their duties without issue. Should problems be found, spot damage is better controlled by killing a small area, leaving the taper profile as it is supposed to be.

I can think of fewer than a half dozen times that I have placed a fine India stone on the taper and face of my lathe (D) spindle. That's over a period of more than 50 years.

H

[SteveM]

...choosing a dull file instead.

Would you create such a file by running a stone across the surface of the file (or running it on a surface grinder) to flatten the points of the teeth?

That would create a tool with edges that only cut forward and not down.

Steve

[BadDog]

That's the gist of it. The resulting file will readily remove anything sticking up, but if used with a light touch on an otherwise flat surface, it will remove only that. Surface grinder would be ideal, but as long as the result is flat (paper on a surface plate? Diamond hone block?) surface formed across all teeth, then that should work.

[jcfx]

I've used precision ground tool room stones to knock down high spots, they seem to work very well on flat surfaces
they'll probably work when used with some care on tapered round surfaces.

[Harold_V]

I've never gone out of my way to create a dull file. I simply use one that has seen prolonged use, and I have my share of them. So long as the file doesn't have that keen edge found on new files, it seems to do exactly what I hope to accomplish--it glides along the table surface without removing any metal, but readily cleans off the tops of dings. A flat stone won't do that, and that's why I don't make that recommendation. I've not stated that a stone doesn't work. It works just fine, but doesn't stop at the dings, just like a sharp file.

H

[SteveM]

I have some long files with the tangs cut off, so I might just dull them with a stone just for that purpose.

Steve

[whateg0]

I think based on the accoutrements that elewayne has a milling vice is in order along with some measuring tools.
A digital caliper, machinists rulers, maybe a micrometer.
For a milling vise I have a preference for the CNC style vises.
Like this one for example, there are other brands with similar styles too - https://www.glacern.com/photos/GPV-615.jpg
A standard import milling vise - https://www.shars.com/products/workhold ... wivel-base

One thing I want to point out is that machinists jacks should shop made, I've never had any luck with store bought, they're
always too tall for my vise and setups.

That looks like the vise I bought, though I guess mine had a different part number. It works fairly well, but the jaws aren't flat. Plenty good for 90% of what I use it for, but it's not a Kurt.

I was going to suggest the same thing you said about machinist jacks applies to many of the tools we use. Get the basic tools, and you can make a sine bar, machinist jacks, 123 blocks. Even in soft condition, they are still useful, and again, for much of what we do, they are probably fine. Moreover, you can spend the money on the things that you can't make. I was able to pick up the screws for a set of Starrett jacks for cheap and turned the bodies myself. Saved a bunch that way. I have also found that the cheap machinist jacks are a pain to use. They don't turn smoothly and the swivel pad doesn't want to swivel smoothly and is always pointed the wrong direction.

I have found that DTIs with the face on the end are more expensive than those facing to the side. I don't have any trouble reading the face, though, because the stylus can be pointed in whatever direction I need it to face. All of mine have dovetails on all three sides.

Dave

[whateg0]

Harold writes:
One thing that a collet allows is the end mill to move under the cut. Holders, assuming you've tightened
the screws properly, avoid that problem. However, the problem is far more imagined than it is truthful, not
that it can't happen. Here's the deal. So long as you understand what "tight enough" means on the
machine drawbar, you can hold end mills adequately secured with a collet, even under a heavy cut.

I get good results using MT3 collets. Keeping the shanks of the cutters and the insides of the collets clean and totally free of oil is essential: I wipe them with acetone. I lightly lubricate the outside of the collet with anti-sieze. I also do something that will horrify most: I use fine emery cloth to lightly sand tool shanks, the insides and outsides of collets, and the inside of the mill taper longitudinally.

For a newby, "tight enough" may not be fully understood. I have a scar in the table of my old mill where a 3/4" EM worked its way out while side milling a piece of 1-1/2" thick steel. It took me a little while to figure out how it happened. I finally saw it happening on another piece shortly after that and it all made sense. I have heard of similar things happening with TTS, so it does happen. Nowadays, I still don't use EM holders primarily because my old round column mill would lose position if I had to raise the head to change them. ER collets have been quite handy assuming DOC is kept reasonable. Metric ER collets are far more versatile, as all of them I have used only have a range of a little over 1mm, or ~0.040". For drills, metric collets let me keep the collet holder in the spindle and go from spot drill, to tap drill, to tap without losing position. (The new mill is a Bridgeport clone with a DRO, so maybe my views will change using it.)

Dave

[whateg0]

If you buy a collet adapter and collet set for the mill. R8 spindle, will those work on my South bend lathe as well. I suppose you would need a mt2 adapter ?

If you are wanting to use the collets in the lathe, too, I'd go for a straight shank collet holder and the appropriately sized spindle-fitted collet. The straight shank can be put in a 4-jaw on the lathe to minimize runout. It just has to be short enough to fit in the mill's collet, but you can accomplish that by cutting it off.

Dave