I made a standard metric pin (using the correct taper angle this time… I know, math is hard sometimes…) and it fit perfectly.
Pin installed
Then it was on to the next issue: some of the way lubrication passages were blocked with crud. I used compressed air and and stainless steel lock wire to clear them out. Because of lack of lubrication over some time, the flacking on the Z-axis retaining plates were worn off (left four holes were plugged (green circles)) - they are interconnected with an internal passage to the supply passages (blue circle). Red circles are the through holes for bolts to attach the plate to the column.
After a bit of work, it now looks like this (plate is 180* flipped in this image)
Plates (one for each side - opposite plate shown here) are made from steel, precision ground.
Because I used compressed air to clear the oil passages, I blew out a sight glass (once the crap cleared) in the column. It bounced around the shop at great speed and broke. It is made of acrylic (plexiglass).
I did not have any stock big enough to make a new one so I went and ordered some 1” rod. Learned that there were two types: cast and extruded. You want the cast stuff for machining; if you get the extruded material, it will crack and chip during machining. Did not know that...
Here are some images of the turning process - this was the second attempt.
[The first part was fine except I was off by 0.05 mm on the OD (it is a light press fit into the column bore; mine was too loose) plus I had trouble polishing the inside of the bore bottom. I had used ~1800 rpm and no lubricant - so part needed polishing as the surfaces were “crazed”. Flame polishing worked on the OD, but part got too hot and distorted when I tried the same on the ID].
Second attempt: 1030 rpm, 0.0015 in/rev, water soluble cutting oil (undiluted), carbide inserts for stainless steel.
Much better! Ready for parting off.
This is the stock material after parting. You can see the jaw contact lines and the serrations through the face of the acrylic.
Parted off, ready for a facing cut.
Faced to dimension (No scratch, just a bit of lint on the inside of the bore).
And the ”Three Amigos” (l.t.r.: original, flame polished & distorted first attempt, and final part)
And installed in the column.
Next is cleaning / inspecting the bed…