Helpful little lathe tool...

by Doc Nickel

I've had a "quick change tool post" on my lathes pretty much ever since I've had a lathe. For those who aren't machinists or are just getting started, a "quick change" toolpost lets you... well, quickly change the cutting tool, with little more than the flip of a lever.

The toolpost uses tool "blocks", a hunk of steel with some setscrews to hold the actual cutting tool. Guys that use their lathes a lot will have a collection of extra blocks, so that a cutting tool can be set, adjusted, and left in place, so that every time you go to use that block, it's ready to go and on center. It's a huge time savings, and reduces fiddling and frustrations.

One of the most-used tools I set up years ago was this:

[linked image]

A standard toolblock with a couple of 90-degree-ground cutters, one at each end. This is my chamfering tool, used to lightly break the corner of parts as they're still in the machine, and a bit safer than trying to use a file.

Being "double ended" like that, you could chamfer both sides of a groove, left and right shoulders, as well as ends and the inside of tubes or bored features.

The main problem I had with this, was that last part- when trying to do the inside corner of a bore, unless you were careful, you could bang the body of the cutter- that is, the part below the cutting face could make contact with the work, which might damage it.

It's just one of those things I've "put up with" for a while now, until about... um... six months ago or so, when I bought a hunk of round HSS for this.

I had a few other things on my mind in that time, but this past week, I needed to start turning some more blanks for another project- about a hundred of them, and both ends meant 200 ends, and both an ID and OD meant 400 chamfers.

So I dusted off the chunk of HSS (er, after I was finally able to locate it, that is happy.gif ) and chucked it up in an electric drill. Using that, I ran it against my bench grinder to form a surprisingly smooth 90-degree point at each end.

I do have a tool-post grinder, and that would have been much more precise, but this was quicker- by a lot- and didn't spray grit and sparks all over my lathe.

After I had a pretty decent point, I roughly ground flats at each end to remove the bulk of the tips, then set the rod up in a 5C collet block, and set that in my surface grinder:

[linked image]

I then carefully ground each tip, so they're the exact same height, and level and parallel to each other.

[linked image]

After that, it was a simple matter of putting that in a spare toolholder- one of the ones with the groove for holding round shanks...

[linked image]

And after that, it was an easy job to plunk it into place after facing each part, and give each edge a quick light chamfer to break the edge.

[linked image]

And, of course, being double-ended means I can do almost any edge on a part- left and right shoulders, both edges of a groove, outer corners, bores and tubes, etc.

[linked image]

I ground the rod slightly below center to give the cutting edge a touch of relief, and there's enough rod I can resharpen it a couple of times- either by grinding the flats again (going even more below center won't hurt) or using the tool-post grinder to reshape the conical part.

But for mostly aluminum, the edges will last several years at a time, anyway.

It's not a huge thing, but it's very much one of those bits where you're happy to have the right tool for the job. happy.gif


Posted on Sep 10, 2017, 12:58 AM

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  1. Must be nice. Dave H, Sep 10, 2017
    1. I used to do that .... Tim, Sep 10, 2017
      1. Used to do the same in CorelDraw. Renegade_Azzy, Sep 10, 2017
  2. To heck with practicality. I remain a staunch lantern toolpost user. NT. AW, Sep 10, 2017
  3. Poor Man's Equivalent. GladMech, Sep 10, 2017
  4. That is so simple that I deserve a slap upside the head for never thinking of it. n/t. pilgrim3, Sep 12, 2017


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