Just Gary and Steve, thank you for your suggestions.
The gib is free. After I removed the rear waycover completely (thanks for the nudge, Just Gary) I was able to get a better angle with the trusty crowbar. I found a big (1"-8) nut that I was able to use as a fulcrum on the "knuckle" of the crowbar, and was able to lever, through an aluminum spacer, the gib almost flush against the saddle.
Almost flush. I reinstalled the rear fixing screw, jogged the table towards me (+Y) and the gib promptly fell off the collar of the fixing screw and jammed again. But this time I knew what to do, and levered the gib until it was just under-flush in the saddle, and re-installed the fixing screw.
It is obvious to me now, that the gib adjustment system depends on both ends of the gib being below the surface of the saddle, so the collar on the fixing screw at each end sits in its circular bore in the saddle and prevents the screw from deflecting and letting the gib slide past it.
My gibs--at least the Y and likely the Z--I haven't gotten to that one yet, seem to be thin enough that to adjust them to spec causes the "thin" end to project past the saddle. That is a recipe for a repeat of this disaster! Since there seems to be enough travel on the front-side Y gib fixing screw, I might just take that gib out and shorten it by 5/8" or so to allow proper adjustments with both screw collars properly trapped in their bores.
But I'll probably wait until Monday and talk to one of the guys at Tormach. I've seen a picture of the newer gib design, and it has a notch to help trap the collar on the adjusting screws. It might be worth my while to buy new gibs.
I did first try the screw-and-nut you suggested, Just Gary, but the nut tended to twist sideways against the bearing plate that I had protecting the column, and wouldn't let me give a direct push to the gib. Steve, I'm sorry but I didnt' see your post until I was already back up from the shop having freed the gib.
The machine is powered down now and I'm ready for bed.
Randy  |