Hi everyone,

I'm a bit new to the CNC routing world and am having issues with my cutter getting badly damaged.

I have built a 3 axis CNC router with a generic 24000RPM ebay Chinese spindle using GRBL as my controller.

Everything is running well now however I have just started trying to do some test pieces on some old plywood. I got myself a cutter from msc, an upcut Kyocera p/n 91113 - a 6mm, 2 flute, carbide cutter designed for wood and plastics. Here's the datasheet: (https://www.kyocera-sgstool.com/uplo...outers_PDF.pdf)

It suggest <=1*D doc @ 31805rpm & 4135mm/min

My spindle can only go at 24000rpm so I calculated that to be 3120mm/min, and I did a doc of 6mm

Thing is when I ran this today for about half an hour, although it seemed like it had cut everything well, I pulled out the cutter to find the tips had sheared off - see attached image... And no it's not a rad cutter!


So far my guess is either
- too high doc
- too low spindle speed (as Vc is 452 with my feed/speed whereas datasheet recommends 480-720)
- should stick with hss
- machine is f****ed / too much vibration or something

I would do more tests but don't want to keep breaking these cutters as they're not cheap!

Please help,
Thanks in advance!!
Max