Andy Pugh wrote: > I seem to be failing to express myself clearly. What I am saying is > that with closed-loop spindle control you will automatically get the > spindle speed you ask for in the G-code regardless of which pulley and > back-gear combination you have selected, as long as the speed > requested is inside the range of the current gear. > I understand the concept, but I'm not sure I like it. Oh, one other thing is engaging the back gear REVERSES the spindle on a Bridgeport! So, unless the logic would read the spindle direction, figure out the backgear is engaged and reverse the VFD, it won't work anyway. So, I really think the computer NEEDS to know about the back-gear selection, at least.
I'd rather be forced to select the proper gears than have the thing start hunting to provide the proper speed. But, maybe that would work pretty smoothly, I don't know. Right now, with the coarse encoder resolution provided by the gear tooth sensor (324 quadrature counts/rev) and the fact that velocity comes out of my canonical encoder non-compliant driver as an integer count per servo cycle, the speed resolution is VERY coarse. I'm afraid a closed-loop scheme would need a lot of filtering, or it would be hunting speed all the time. I am hoping to fix that encoder driver at the CNC fest this summer. Jon ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
