I need to tighten my tolerances on my cutting depth and am looking to level my waste board. I’m more concerned with accuracy than cutting time. Is a fly cutter the best tool for the job? Will I get a more accurate or smooth surface using a larger or smaller bit?
I use the Freud 16-106 mortising bit with a 30% stepover. It produces a nice finish. Not a fly cutter by trade, but close enough and the trim routers can handle it.
I used a 1/2" two-flute router bit I had around. As other have said; take light passes, light speed with a pretty aggressive step over and it goes pretty quickly.
I tried a 3/4" cutter and a 1/4" endmill. I liked the finish from the 1/4" endmill better. I just set it to cut 0.05" deep with a 0.2" step over and run it at 200ipm. It doesn’t take that long and looks great.
The larger the bit the more you will see issues from flexing or your spindle being out of square.