Gingery Metal Lathe

(You can click on a photo to see a larger version.)

I was able to find a piece of brass tubing which fits perfectly between the shaft and the crank, keeping it snug and perfectly centered when the set screw is tightened. 

I also found that the shaft had a tendency to wobble and bind a bit when turned, so I added a second collar with set screw between the crank and the cross-slide casting, and cut the brass tubing to extend all the way through the crank, both collars, and the casting.  This makes for a nice snug fit when it's assembled, while reducing friction and allowing smooth movement when the crank is turned.

Here's a bottom view.  There's a bit of discoloration in the center support rib, since the sprue was right above it and I think things got a little warm...

Side view.   A little bit of "flash" where I repaired a bit of crumbled sand before pouring.  I prefer to err on the side of a little extra metal.  My "Putting On Tool" is in for repairs...

The lathe bases, which I poured yesterday, after some preliminary cleanup.

The apron and headstock caps as they came out of the sand.  I had the patterns ready at the same time, so I cast them together off a common sprue.  It was near sunset when I started, so I ended up pouring by the light of the glowing aluminum (no electricity in the barn... yet...).   It was pretty   interesting, actually.  I got to see all these little flames dancing over the surface of the oil-bonded sand for several minutes after I poured; I assume it's some of the oil burning off...

Here's a closeup of the left end of the lead screw with bearing journal, bearing, and pulley.  Careful observers will note that the bearing is, in fact, a modified commercially cast "pillow block" with brass bushing.  After 3 attempts to cast the Gingery-model bearings ended in failure due first to pattern problems and then to gas pockets in the castings, I did what any red-blooded American would do; I gave up and threw money at the problem. ;-)  I bought a couple of pillow blocks with the correct bushing diameter, sawed off the mounting bolt flanges, drilled out the tapped holes that hold the bearing together, and replaced the included screws with some that were long enough to go all the way through the bearing into the bed and base castings.  By carefully filing down the bearing bases, I was able to get the lead screw to the proper location, and create a snug fit between the bearing and the lathe bed/base castings.  For some reason, I have a lot more trouble making and pouring little patterns than I do big ones; so far, on the whole project, I've only had to re-pour one base casting and the compound-slide casting.

This view of the lathe that makes it look like it's the size of an aircraft carrier.  You wouldn't guess that it's only 2 feet long!  Next up, I have to cast the leadscrew crank (I'm thinking brass just for looks...) and the split nut and split nut lever, and build the boring bar   support assembly to bore out the headstock!

This was a pain in the butt.  For some reason, I had a terrible time with this casting.  Part of the problem was that I didn't have the dowel in the pattern extending above the top of the center ball, so it was hard to get the steel core positioned correctly in the mold.  I ended up having to melt the core out of messed-up castings on two occasions.  After I added a dowel at the top of the pattern to leave a better alignment print for the core, I poured a brass crank because I thought it would be pretty, but it ended up with a shrink cavity that ruined the ball at the crank end.  <*sigh>  It being my 4th attempt and all, I abandoned brass, at least for the moment, because I thought it caused the cavity.  After two more attempts with zinc, still with shrinkage cavities, I finally added a riser to the mold, right next to the ball end, and that did the trick.  <*whew>

Here you can see several new pieces, including the cross feed (minus the crank and feed screw; I'll get to that soon.  For now, I've just got the gib screws cranked down tight...) the half-nut engage lever, and the tool post.  Not visible are the half-nut (I'll try to get some pictures next time I have the thing apart) and the spring-loaded pawl which holds the half-nut in the engaged or disengaged position.)