[How-To] Is this tool positioned correctly?

[finsruskw]

to advance to the left say .010"??

 

[gonzo]

Be aware that I am just a beginner, but I think it would be too large a bite, Better to take it off a little at a time,

 

[Aukai]

My hack idea would be to change the lead angle(lay it back), and at .010 face out to make it square. I'm thinking about the shoulder rubbing, and making things unhappy. I just want to see what the experts have to say.
Maybe shorten the stick out some too???

 

[Ulma Doctor]

your stick out is too long.
other than that the tool can work in that orientation.
i would tend to do the longitudinal cut, then traverse out of the cut

 

[aliva]

Shorten the stick out of the tool , this will increase rigidity. Not sure what he hp of your lathe is but if under 3 hp take a .0020 cut, or what ever your lathe will tolerate. If you want a 90 degree shoulder at the end of you cut leave the tool as is.

 

[benmychree]

Agree, stick out is too long, other than that, fine; I assume that the step was made in multiple cuts.

 

[finsruskw]

Benmychree,
Yes it was, multiple passes.
I am assuming here that square with the chuck is the way to do this.
Does the tool holder always have to be square w/the chuck?
I have several pieces to make like this.
A 1" dia. piece, 1.5" long, down to 5/8" on one end for 3/4"

Is CRS best to use for this rather than HRS??
Lathe is 3/4 hp SB 9A

 

[benmychree]

The tool square to the chuck is mostly OK, but sometimes, especially on lighter machines, the tool may tend to draw in while cutting, so roughing with a tool with a lead angle may be prefered, or the tool cocked in the holder to provide a lead angle, then finishing with a tool in position like you show. Yes, CRS is best, much easier to cut than HR; if the piece does not have to be welded on to something, 11L14 is even nicer to machine.

 

[mikey]

Finsruskw, most inserted carbide turning tools are intended to be used with the shank of the tool holder perpendicular to the work piece. However, your tool is a very old style geometry and was originally intended for lathes larger, more rigid and more powerful than yours is. Actually, your lathe was intended to use HSS, not carbide. Be that as it may, you will find that this tool cuts easier and cleaner if you angle the tip of the tool to a 5-7 degree angle towards the chuck for both roughing and finishing. The reason this is so is because this puts a lot less edge contact touching the work so cutting forces are thereby reduced. In this position, the left edge of the insert takes material off while the nose radius leaves a better finish behind. Try playing with your lead angle and see what happens.

More modern tools, like the SCLCR tools, have a 5 degree angle built into the tool when the tool shank is perpendicular to the work. The reason it works better than that old style tool is exactly for the reasons stated above.

I also agree that you should minimize overhang of the tool.

 

[finsruskw]

Thanks Mikey and others.
I have 4 pcs of 1/2 x 1/2 HSS that came with the grab bag of stuff I picked up on C/L last month so will try and
grind a couple of those using the models I made last winter as a guide and play around with them and see what happens.
I milled down a short piece of A2 3/4" square stock this afternoon to fit my chuck as I had no key for it.
Have to put a hole in the end of it yet for a handle and may mill a groove down each side just for the heck of it.