Rounding over an edge

Seems to me that this should be fairly easy but I really haven’t tried it. I will be making some presents and want to round over the edges on the CNC. My thought is to carve the piece, cut the profile (with tabs) then run another toolpath with a round over bit. Sounds good but I need help defining the tool path for the round over and what bit I should use. Any help will be greatly appreciated. Thanks.

Depends. For some things, the old way is the best way - do it with a router and a roundover bit (just because you have a hammer doesn’t mean everything is a nail :slight_smile: ).

Another way you would do so on the CNC is to define a roundover bit (probably as a chamfer bit), create a toolpath the follows the edge, and see how it looks. The preview will not be accurate. Try it. If it looks ok, you’re good. If not, adjust the angle of the chamfer endmill until it’s about what you like.


I did this with a 1/4” radius round over bit. The bit I used came to a point, not the kind with a bearing on the end(don’t use bearing type router bits on your CNC). I set the tool path to run a profile “on” the lines and set the depth to 1/4”, same as my radius.

Came out pretty good, but I didn’t get my Z axis zero perfect and ended up with some sanding to remove tool marks. Like Mike said, if you have a router and bearing type bit it’s likely much quicker. For something like mine though it would have been tough because of the clearances. All depends on what you’re after and what tools you own.



I use them in the shapeoko all the time on aluminum. Beast but sling chips like nobody’s business.

But like Mike said not always needed, complex shapes get the cnc, simple gets a hand routing on the table. I used create and just created a tool with the lower diameter and fed very carefully going deep, up to 0.5 rad on al. Might do the same in fusion is it gets too complicated defining a form tool.

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I do round overs and chamfers on my edges all the time. The trick to getting a clean edge is to NOT run it along the same profile line otherwise the point is going to do a little cutting into your vertical side and you don’t want that. You offset the line a couple of hundredths and run it on the offset. I explained it here


Thanks I will give that a try.

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