I would dare-say that while no machinist could detect changes faster than a pilot, the feedback is needed in machining, on several orders of magnitude. With high-speed machining processes and S-curve acceleration being used (a welcome upgrade for the hobbyist/home shop user) it's far more important for the machine to be able to address any issues that might crop up...that is what is so great about CNC...the control SHOULD be doing all of the machining work, once a setup and program are optimized. In this case, it's all about putting the heavy lifting on the computer, not the operator.

Quote Originally Posted by keick View Post
Not nessecarily. USB isn't real-time for certain, but there would be multiple reasons for the hardware to cache ahead to compute rates for turns and such. USB or Ethernet would be bulk transfers, and periodic responses back to the host machine if desired. I'm in the avionics development field. Most avionics displays only update at 30Hz, because pilots can't detect changes faster than that. Maintaining a 30hz feedback to the operator via USB or Ethernet is well within the performance of those interfaces on RT Linux, or windows for that matter.