There are three ways to do this:
To trim an arc out of a circle, there are a couple of options:
Draw a circle:
Go into Node Edit mode:
right-click and use the "Cut Vector command where desired:
Done
delete what isn’t needed:
Assign a suitable toolpath:
which previews as:
Alternately, the Trim Vectors command may be used — in addition to the circle, draw geometry which defines where you wish the cut to be made:
Note that it will be necessary to increase the size/offset by the radius of the tool which will be used to make this cut:
Select the offset geometry and the circle:
and use the Trim Vectors command:
to delete what is not needed:
and apply a toolpath as before:
which previews as:
Doing this using Boolean operations is similar, but one needs two circles, one to describe the shape which will be left, the other which is offset by tool diameter plus ~10%:
Select the offset geometry which defines the region to be cut and shift-click to add the inner circle to the selection as the key object:
and use the Boolean Subtraction tool to remove the area encompassed by the circle from the offset geometry:
OK
Add the remaining circle to the selection and use Boolean Intersection:
OK
