My point-cutting round-over bit leaves a lip at the pocket edge or uncut material in the corners. How do I set up the toolpath?

Why it happens

A point-cutting round-over bit has its tip on the centerline, and the curved profile grows outward from that point. The curve starts where the tip runs. If the profile toolpath is set to cut Outside or Inside the line, the software shifts the bit sideways by its radius, the curve starts away from the pocket edge, and an unwanted lip is left between the two.

The fix

1. Select the same vector that defines the edge to be rounded (for example the pocket boundary).
2. Create a Profile Toolpath with the round-over bit.
3. Set Machine Vectors to On the line. Educators report that this type of bit normally needs to run directly on the vector.
4. Preview it together with the pocket toolpath. The curve should begin exactly at the pocket wall. If a lip shows, the side setting is wrong or the bit is entered with the wrong size.

Uncut material in tight inside corners

The bit's body is too wide to reach into a sharp inside corner, so a small wedge is left. An educator's workaround:

1. Draw a small triangle vector over the corner.
2. Pocket that triangle with a small end mill.
3. Then run the round-over toolpath.

Getting the bit into the tool database

• Round-over and ogee cutters are entered as Form Cutters. Draw only the right-hand half of the cutter profile at exact scale, select it, create a new tool and set its type to Form Tool.
• Use the maker's DXF profile if one is offered. It is more accurate than drawing from a photo.
• Profiles imported from PDF often arrive as many tiny straight segments. Redrawing them as smooth arcs in Node Editing gives a cleaner cut.

When a router table is the better tool

For a plain round-over on one cut-out part, one educator points out that a router table is often quicker than setting up and zeroing another CNC toolpath.

Pro tips

• Verify that the bit's real dimensions match the database entry. A mismatch leaves ridges or oversized cuts.
• See the entry on adding bits the software has no type for.