You can see it here in this video I made about threading a gun barrel: https://youtu.be/RmNKIjr6LG8?t=54
Adjustments that exist on the Grizzly tool version, or other JET knockoffs of what seems to have been a South Bend design, aren't here, the maker here just left some big clearances on things by milling metal off the castings to avoid any binding, but then didn't put back the setscrews, pads, lock nuts and so on. So...here we go.
Some of this stuff is insanely hard to get to and at some point I should leave myself and others some notes on how I got this apart without spending more than one all-day on it and also without bending things too much. It's a hassle. The bar pictured here is up under the front of the saddle, hidden by the gear box for the normal power drive stuff and even 12 point wrenches don't quite serve to turn those bolts that hold it up under there. Here it's shown laying on top after I've cut some pockets to insert some brass bits in that I can push up from underneath with setscrews. With luck this is better than the official version, which would have required magic to adjust anyway in this configuration.
- I've added the brass pads shown here.
I'm not kidding about the tight space - here it is installed...
- I had to make special lock nuts to fit in this space!
These pads take up nearly 20 mils of clearance the factory left. That clearance allowed the saddle to climb the inverted V of the bed ways and shift back toward the operator when pressure was applied by the tool hitting the cut. This has a similar effect to the work springing - you wind up adding more force to get a cut to begin rather than rub, and when the tool bites, it suddenly cuts too deep, wrecking your part.
A similar clearance existed on the backside of the main saddle, on the vertical part of the L way back there. It had an ajustment for vertical clearance, but a 100 mil gap allowing this horizontal motion back towards the operator. Just in case, I added a brass rod to bear on that surface, driven by a /4-20 bolt. I had to drill and tap a 3/4" thick piece to get this one going on, and sorry about the lousy focus on the pic here.
- Bolt on the back, sticking down in pic.
I've not really thrashed this yet, but an indicator shows that serious human-applied pressures no longer make the thing climb the V and move back towards the operator, so it might be good.
An examination of the previously untouched but already nicely machined bed way surfaces I'm now riding brass contact pieces on shows a nice little wear-in deposit of brass on the cast iron where I expected it to go, so fingers are crossed.
- Underneath the front - see stripe on the previously untouched underside of the way. The brass color doesn't show well in the pic, but is clear to the naked eye.
Ditto on the back - the 3/16 diameter brass rod I'm pushing into the vertical way surface back there instead of having 100 mils empty space for play leaves a mark, but in this case, that's a good thing. At least that side has plenty of clearance to stick in a wrench to twist the bolt.
- See stripe in the mirror. Surface was already machined but never touched before this...
I'm going to keep banging on that broach tool I want till I have one, doggone it.
- "All together now" and I might be able to save this workpiece- only one land is ruined and by golly, I'm going to have that special broach.
