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Ok, that would be interesting to know. How do you set the angle?

John

John

As an Instructor I normally teach that the tool should be at or just below center,

and as square to the part as possible, the square up with the chuck or spindle nose is usually

good enough for a second op part. I normally use a high quality grooving tool if my part off is

the finished surface. (for thin walled parts of course) otherwise I will finish with a second op.


Bob

That's pretty much how I do it on the CHNC except I've never used a grooving tool to part off with.

John

Hey John,

I ask over here and I found out I left out a critical detail. The height should be WITHIN the specific angle range (0-1.6 degrees) below the center, and this has to do with the rigidity of the tool and machine and the hardness of the material. The harder the material is the further close to the low end you'll want to be to keep the tool from grabbing or chattering.

To figure out how far below the cutting edge should be you just take the sin of the degree you want to use and multiply by your outer radius. This will give you the height below center in the same units as you measured your radius.

Saludos cordiales,
Frank

The tool must be below the center line because there is vibration (chatter).
When vibration occurs, if the tool is upper the center line, it tends to lock (clamp) over the piece breaking itself; if the tool is below the center line, it tends to unlock.