Where to buy a half-round lathe tool bit?

[ThomasAlva]

I am trying to make some miniature train wheels to ride on some round stock.

I want to know where I can buy a lathe cutting bit that will allow me to make such wheels.

I don't need a quarter round, I need a half round. Thanks in advance for any advice.

Regards.

[RICHARD ZASTROW]

A round tool will leave a half round if you plunge straight in the rim of the wheel. What size round do you need? Lathe inserts are sized at least down to .187" dia.

[ThomasAlva]

A round tool will leave a half round if you plunge straight in the rim of the wheel. What size round do you need? Lathe inserts are sized at least down to .187" dia.

OK, then I can use a round tool as well. Know any online suppliers?

[RICHARD ZASTROW]

Seco-Carboloy inserts: RCGS, RCMM, RCMT, RCMX, RNMA, RNMG

www.secotools.com ecatalog turning inserts

[ThomasAlva]

Seco-Carboloy inserts: RCGS, RCMM, RCMT, RCMX, RNMA, RNMG

www.secotools.com ecatalog turning inserts

I got to navigate that site a while. when I type in any of those above acronyms (I don't know what they mean, sorry) into the search, it doesn't list anything.

[RICHARD ZASTROW]

Those are the code letter (catalog numbers) of the inserts.
www.sectools.com will get you to the site.
click on "ecatalog" to get to tool type selection. Click on "turning".
select & click on "turning inserts". Then you will have to scroll around to the round insert pages where you will find the above combinations of letters with accompanying charts describing the inserts size etc.

[ThomasAlva]

Those are the code letter (catalog numbers) of the inserts.
www.sectools.com will get you to the site.
click on "ecatalog" to get to tool type selection. Click on "turning".
select & click on "turning inserts". Then you will have to scroll around to the round insert pages where you will find the above combinations of letters with accompanying charts describing the inserts size etc.

Thanks!
Done

[Mcgyver]

If I'm understanding you properly, you plan on using it like a tangential cutter? won't work, no clearance. just make some up out of drill rod then you can cut the clearance in. better still use a boring head as an up and over radius cutter. here's a pic of a tangential style one i made many years ago, made a set off wheels for a tube straightening mill (for smallish copper tubing) but if was doing it again the up and over is the way to go imo

[RICHARD ZASTROW]

Mcgyver, Your tool/method obviously works. Just FYI, the button tools will also work. If you look at the www.secotools.com site, page 133 (turning-toolholders, external) toolholders TRAOR, TRAOL AND TROON , all use button tools. We used these to plunge but more often to contour deep slots in forming rolls. Those little buttons will suprise you. Get the SECO rep to get you a freebee to try.

[Mcgyver]

ah I see. when he said round tool bit i thought he was looking for round hss instead of regular sq, hence concern over clearance, obviously not an issue with inserts. thanks for clarifying

[ThomasAlva]

If I'm understanding you properly, you plan on using it like a tangential cutter? won't work, no clearance. just make some up out of drill rod then you can cut the clearance in. better still use a boring head as an up and over radius cutter. here's a pic of a tangential style one i made many years ago, made a set off wheels for a tube straightening mill (for smallish copper tubing) but if was doing it again the up and over is the way to go imo

Yep, that's exactly what I'm trying to make, minus the broached keyway.

So.. if I take some drill rod and cut off the fluted end, and just leave the shank, the shank side will be sharp enough to cut into spinning round stock?

I just have to be careful to have the drill-bit shank locked down pretty tight, right?

I'm very much a novice at this, so if I'm exposing my ignorance... then indeed my ignorance is exposed.

[riverrat]

I know this may sound "stone age" to some of the guys here,,,, but
why don't you buy a hss blank and grind the damn thing?
thats how it was done before carbide tools, cnc, etc....
those carbaloy tools are good, but pricey for the hobby guy.