Two days ago I received a bit that I had Royce/Ayr Cutting tools make up for me. I do these carved top cutting boards (quite a few yearly) and have been trying to get my time down on the machining - and also a better machined surface as to cut down on sanding time.

I was using a box stock "bowl and tray bit", 1 1/4" diameter with a 1/4" radius bottom edge. Running about 240 inches per minute and 13,500 rpm, with a 31% step over. Cut pretty good, with a decently smooth surface.

The bit I had made is 2" in diameter, with two carbide inserts, also with the same radius. The inserts are set to up-shear cut. Also, with a 3/4" shank (the maximum I can run in my spindle). Its a fair bit larger than the other one!

Today I finally got a chance to test it out. I did a test cut in a scrap of hard maple, then put one of my cutting board blanks on the machine a did a test cut at the same feed speed, 13,000 rpm and same step-over.

Cut the machine time from about 7 and a half minutes, to just under 5. I need to play with the cutting speed and step over to see if I can shave it down to 4 minutes (I was hoping to cut the machine time in half.

I would say the cut quality is better than the bowl bit, especially around the perimeter. I hit the cut section with a ROS and 120 grit for 30 seconds or so and removed all the visible machine marks, so they were very minimal, with no chips or tearing out.

I wish I had more time to spend trying to push the bit, but that will have to wait a bit longer. But if I can get to my target time, I can possibly save nearly an hour every time I do a run of a dozen of these.

The bits


Off the CNC router


After a bit of sanding


Here is a video of the cut..

https://www.youtube.com/watch?v=1JKJ...m-upload_owner