Hi all,

Would love some input or suggestions in my still-in-my-mind CNC build that uses a rotating knife instead of a traditional spindle. I'm looking at having a rotating knife as the A axis (i.e. a separate Nema 23 motor can rotate the knife blade 360 degrees) so that the knife is always pointed in the correct direction when cutting. Here's a google image that's similar:



While it's hard to make out in the picture, it looks like the knife is mounted on a white plastic disc, and that disc rotates relative to the aluminum base that it's mounted on. The stepper motor is mounted to the aluminum with a motor pulley and timing belt connected to the underside of the knife to control the rotation.

My question is how to mount the plastic to the aluminum. Best to use thrust bearings like these ? Something totally different?

Thanks!