Open the Easel project http://easel.inventables.com/projects/jGNJtvIGTTOVv2v2oUlvCQ
Choose the orientation that you want to use and delete the other one.
Set any parameters that may defer between your material/tool and mine (e.g. thickness).
I used a 3mm MDF painted white on one side (recuperated from some IKEA furniture).
It doesn’t matter whether you use the same MDF or HDPE or even some other kind of material. I just like the two-colour effect because it makes the lines easy to see.
Because you cannot tell Easel in which order to carve, you have to start by deleting the outline to avoid having your piece cut out right from the start.
Select the outline half-circle and delete it.
Carve the inside lines (all at 10º from each other) and the centre dot. I used a 30º engraving bit for an aesthetic look.
Click on “Edit>Undo Remove” to get back the outline that you removed previously.
Now select all the inside lines and delete them so that you can carve the outer half-circle to cut the protractor out of its sheet.
Make sure the depth is the thickness of your material (mine was 3mm).
Carve the outline, either with the same engraving bit or with a straight bit.
Done! No need for sanding!