How to CAM a Reverse Corner Rounding Endmill

[Anonymous]

I have a part (shown in the attached drawing) where I want to round the inside edge of a hole.

To do this, I want to use a reverse corner rounding endmill like the Internal Tool #67-1425.

I have figured out how to make a form tool but I cannot figure out what tool path to use.

Because the end of the mill is actually wider than the cutting edge, the tool would first have to drop down the center of the hole, then move out towards the radius where the tool will engage, before tracing the circumference of the hole.

Finally, the tool would need to move back to center of the hole before retracting.

Any guidance on how to do this appreciated.

[seth.madore · Accepted solution]

In this case here, it's going to be a bit of trial and error. Define your form tool, but select the upper edge for the compensation point:

And then play with the Stock to Leave settings until you get something close to what you are looking for:

I've attached a sample file, hope this helps!