Size of object with outside cut

Hi guys - I had an issue on the weekend where I wanted to cut a rectangle shape that was 100mm wide. It was to fit into a slot that was 100mm wide - simple male/female fit.

I was using the .125" Endmill and chose an outside cut - it is tool 201 in CC and that was the tool I used. My assumption was that CC would account for the tool size and cut the perimeter of the object such that it would be 100mm wide. That wasn’t the case - it ended up approximately 103.8mm wide.

What’s going on here - am I missing something? Is there some part of the tool width I need to manually account for? Is there potentially another issue I’m not aware of - calibration? Thanks.

CC does account for the tool diameter, and the machine accuracy is around +/- 0.1mm (at the worst), I’d say this was probably operator error. You should always post your CC c2d file too so that we can look at your setting.

1 Like

Operator error? I’m not familiar with that term… :smirk:

1 Like

never mind. . ……………

#201 is the 0.25" end mill and #102 is the 0.125 end mill. Your machine thought it was cutting on the line with an end mill twice as wide as you were using.


You know what - you might be on to it. In my mind I know #201 is quarter inch and #102 is eighth inch but I may have got them mixed up when selecting them in CC.

This clearly isn’t operator error - i’m blaming your “freedom units”…y’all heard of the metric system yeah? :wink:


Just checked my file and you were right Maxamillion, I was using a 0.25" bit while selecting a .125" bit in CC and when using the 0.125" I was selecting 0.063" in CC. So simple, but big difference, thanks.

1 Like

You are not the first creator to mix up the bit selection, either in the design or at the machine, nor will you be the last. I have generated G-code with two different bits into one file… the results are not what you were hoping for when the machine continues on to the v-bit toolpath with the 1/4" endmill that was used to hog out the initial material.