Started on a my first real cutting project and made a couple prototypes. I am using poplar wood (soft) right now and cut a series of narrow channels approx. 7-8 mm wide x 6mm deep with a 3mm spiral up bit cutting 3mm deep at a time. I seem to be getting a lot of ragged material let at the top edge of my cuts. Looking to avoid some trial on my part and error by asking for some ideas on what I should try adjusting.