Lathe cutting tool angles

[jonathan01]

I am finally getting my lathe ready to cut. Looking at the angles of a rh tool. I am wondering what angle should the side cutting edge be at. I pretty much gather that you start about 1 1/2 times the width back, but what angle is good. I seen where Tublacain has 2/3 of the height, and I also seen only about 4 degrees. Also the front edge angle, is it 85 degrees from the cutting edge for turning, and 55 degrees for a facing too?

 

[joe_m]

Here's a link to a tutorial that includes angles for different types of material. It's a very good start. My personal inexperienced opinion is that a very sharp edge is more important than being right on with the angles - as long as you've got enough clearance that you're not rubbing and the chips have room to clear.

good luck
Joe

http://littlemachineshop.com/instructions/GrindingToolBits.pdf

 

[pineyfolks]

This might help

 

[jonathan01]

Here's a link to a tutorial that includes angles for different types of material. It's a very good start. My personal inexperienced opinion is that a very sharp edge is more important than being right on with the angles - as long as you've got enough clearance that you're not rubbing and the chips have room to clear.

good luck
Joe

http://littlemachineshop.com/instructions/GrindingToolBits.pdf

That was great info, but what I am really looking for is the Side cutting edge angle, and the front cutting edge angle.

Thanks,
Jonathan

 

[Ray C]

Hi Jonathan...

Ah, I think you're asking about the angle relative to the workpiece -if I'm not mistaken. Have a look at this thread that talks about using and checking the compound angle. http://www.hobby-machinist.com/showthread.php/10856-Lathe-Using-amp-Checking-Compound-Angles

In some of the pictures, you'll see bits that are setup for face and side cuts. The angles are about right for low to medium depth cuts. The angle relative to the workpiece is relative to the style bit you're using and the desired depth of cut -as well as if the bit has a chip-breaker groove cut into it... The point being, there isn't an easy answer to your question.

Another thought to keep in mind when making your cuts, is to have minimal stick-out of the bit from the tool holder or, you'll get some interesting chatter noise and ugly cuts. Keep that on the back burners as you go.

Ray

 

[jonathan01]

Hello, I have been busy the last two days. I links yall posted were great, but this is what I am really looking for.

Thanks

 

[jonathan01]

Hello, I have the side of my tool done, now I am starting to grind the front of my tool.

The tables call for a 8 degree front relief, but my HSS blank has a front relief pre-ground to about 11 degrees.

Should I follow the same relief angle, or change it to 8 degrees?

Thanks