"Bob La Londe" wrote in message
...
http://www.yumabassman.com/pictures/...20Axis%20b.JPG

Well, there it is. It's a combination of design to fit and machine to fit
techniques, but it screams up and down at 40 IPM. (Fastest I can run
without changing the kernel speed.) I expected to be able to stall it
very easily with the stepper running that fast, but I was unable to stall
it by bracing my hand against the table and bushing upward with the axis
rapiding downwards. (I think the G450 must switch from micro steps to
full steps over as certain step rate. I'll have to ask Marcus about
that.) Now I probably need to map the screw. Repeatability is very good,
but accuracy is pretty bad at different distances along the screw. I
never had to map a screw before. Funny that the first ball screw I
install has the worst accuracy of any screw I've used. LOL.

Just for the heck of it I bumped the kernel speed up to 65khz and I got 53
IPM on rapids without stalling on a 25.4 TPI (1mm) screw. That's nuts. I'm
tempted to bump it up again just to see where it does stall.