O.K. I thought that you had perhaps done that well on a single fast approach, which would have been *very* impressive.
It is only a 5" swing -- and perhaps 10" between centers. There is a steel splash backplate which also includes the electronics, with the keypad and readout at the upper right-hand corner, and most other things high enough to be above the splashes.
To zero it (for each tool) there ia a bed-mounted microscope, so you zero the Y and Z Axes for the first tool move to the intersection of the cross hairs, then swap in the other tools and write down the offsets as you move the tool to the same intersection. But there is no provision for storing the offsets in a single place in the program -- you have to enter the offsets *every* time you call up that tool. A royal pain.
I've been collecting servos of various sizes, and have some which are not that much larger than the steppers, which stick out from the end of the bed and where the cross-feed crank would otherwise be, so there is room for *them* at least. No provisions for linear encoders, so I'll have to put a rotary encoder with each servo motor.
[ ... ]
Well ... that tells you which trace is likely open. Perhaps it is an open via, and simply filling it with fresh solder might make it work.
O.K. When driving the knee -- is there automatic gibb locking between motions?
[ ... ]Hmm ... what if you need to cut a 13-1/2 TPI thread? That might be difficult with the 2:1 coupling.
Of course, an encoder directly on my Clausing's spindle would be difficult with clearance for a 5C lever-acting drawbar. So -- the trick there is to add another gear engaging the spindle's own gear -- and ideally a spring-loaded zero-backlash gear for that. Another use for the set of gear cutters and the index head on my (very manual) horizontal mill. :-)
O.K. I could probably do that as fast on the Clausing, using the bed turret and a Geometric die head. 3/4-16 is within the range of the sizes which I have.
I really don't want steppers at all. It was bad enough trying to cut a Morse 2 taper with the Compact-5. Not only was the resolution limited ot 0.001" or 0.01mm -- but it was measuring radial dimensions, so the diameter goes in steps of 0.002" - *that* I could see with my bare eyes. Servos, told to move at speed N for one axis and speed J for the other will cut a very straight taper.
The Bridgeport BOSS-3 has two tapered roller bearings ground to fit together to mount the ball nut (which is rotated for the 'X' axis, with a fixed ball screw simply clamped at one end, so there is less whip with rapid moves). There is very little measurable backlash there.
The 'Y' axis leadscrew does rotate -- but that is only for a 12" motion, not the 18" for the Y axis.
The 'Z' zxis is a ground hollow ball screw around the quill, and another rotating ball nut to move it up and down, so the force is concentric with the spindle axis.
Perhaps -- but I really want servos on those when I EMC them.
Enjoy, DoN.