How do I make toolpath for this chamfer? MASTERCAM (solved)

5 Answers

I'm assuming a 3-axis mill... no swarfing capabilities.

If it's a constant angle, you might be able to use a chamfer mill ground to a point, at that angle. I don't like using those to cut along a floor because of the low surface footage near the tip making it easy to overload... but you do what you have to in these situations.

The other option is a z-level stepdown type cut along that arc'ed path. You could use a flat bottom but that's going to yield a lot of cusp. Better to go with a bullnose of small corner radii and find out if the radii at the floor will be acceptable.

Explain this to the designer... as he/she could obviously learn a few things from the input.

Actually... it doesn't need to be to a 'point' and would actually be better--for reasons mentioned--if it wasn't.

I'd edit the previous comment if I could...

The first thing I notice is that you don't seem to be using a dynamic toolpath for the roughing. That would reduce your cycle time.
CMALCO is on the right track. For more detail you can get yourself a membership to Streaming Teacher ( They have great, short, searchable videos that walk you through every part of Mastercam.

Economics of part making...

If you're making 1 of these on a low-speed machine; step down with a chamfer mill is feasible and you likely already have the tools. If the chamfer's small enough to be covered by one pass, then you may opt to rough and finish, leaving floor stock to get a better blend into the floor on the finish pass.

If you're on a high speed machine, it might be just as quick to do z-stepdown, back and forth along the arc. When I worked in R&D mold making, most of the machines were >30k rpm and it was rare that we ever found the need for a chamfer style mill. Just meant another tool change and by the time we got a new one in the cut, the bull or ballnose would already have finished it.

Now if you want to keep a large chamfer mill on hand, the inserted units from Seco are sure nice to have and they're insert layout is actually helical in nature.

imho, Grind that angle onto a 4 flute end mill, using mastercam you can set your depth of cut to step down at the desired angle per pass, so you don't need the entire angle on the tool. just a little bigger than what your depth of cut is. don't use a chamfer mill or a pointy angle cutter. The end mill will allow you to blend with the floor easier. HTH