Use tape and super glue to make sure the circles stay put while cutting. Put the smaller circle in the bottom side of your sweepy dust boot. use pics for reference. insert pen tip and then pen. put spring that comes with pen on top side of pen, followed by #6 washer. add bigger circle on top (might need to ease edges/sand a little to get it to fit). push from bottom side to adjust spring tension. As for a toolpath & feed-rate for drawing, I used a 1/32" #122 endmill contour path with no offset & a 1000mm/min feed rate. I'm sure this can be improved but it worked fine for me. Just set your zero using the pen tip and make sure the spring is pushing hard enough. good luck & have fun! :)