Forty-odd years ago I was into lapidary work as well. Did a lot of reading, and collected a lot of stones that I wanted to cut and polish, but didn't get to actually do much of that until I enlisted in the USAF. The first couple of bases I was stationed at had lapidary units in their hobby shops, among other things, so I used their equipment for a while. I did look into making my own lapidary machines, as I had other things to spend my munificent salary on, but didn't actually get to do that. I did collect a few old Lapidary Journal magazines, and they sometimes had articles about folks building diamond saws, sphere cutters, cabochon and faceting machines, and the like. I learned that laps were often made of copper, tin, and lead, among other things, and that some of the commercial cab machines had spindles of hard rock maple.

Check YouTube. I found this sphere machine that looks much like stuff I saw in those old magazines in a quick search:


DIY lapidary machine got this video, and the side bar has a home-made lap in another video.



Might all be good info!

HTH!

Bill in OKC