I’m asking because I want to know if anyone else has been down this little rat hole with some good tips to share.
Chamnit says 100khz is achievable. At ~40 steps/mm, that’s 2500 mm/sec as max feed out of GRBL. But, acceleration isn’t instantaneous (if you go from 1 step/sec to 100k steps/sec with no acceleration, you’ll just skip steps.) Probably also means pulse length might need to be decreased to get there (which is also a whole can of worms). Default acceleration (for shapeoko3 config) in each axis is 400mm/sec. which means at 6+ seconds of acceleration is required to get to 2500mm/sec from 0. In little 5-6 inch rapids, you’re probably not getting more than 200-300mm/sec (remember, it needs to accelerate and decelerate, and there’s not much time there)
If I increase acceleration (say, to 1000mm/sec), I get steps skipped. Yes, tried it. More torque should mean that acceleration value can be greater. How much more? 2000mm/sec? 3000mm/sec? I don’t know. Easier to find that one experimentally than my-awefully-rusty-calculus can calculate.
Clearly higher acceleration = more time at max speed = faster rapid, and you want that acceleration as high as you can get it without skipping steps.
Of course, all of that’s going to put some higher forces on the frame, so will have to see how that works out, it may make it all totally pointless, but don’t know till you try…