A little help please Doing an engraving path on premium birch plywood. These numbers are approx 15-20mm tall. Using a 30 degree sharp point bit. First pass is 0.4mm deep and 2nd is 0.6mm deep. Running 40IPM and RPM around number 3 on the Makita. Anything else I can do to eradicate this chipping or is this the best I can get, especially as its plywood?