Machined my first brass rings on the lathe and they actually fit

I made something similar last year, a stack of brass discs with a steel shaft through the middle and a couple of 608 bearings pressed in. Mine spun nice but wobbled like crazy because I never faced the discs after parting them off, so the faces were not square to the bore. If your rings run true when bolted togehter you did better than I did on round one. The parting cut is what got me too. I fought chatter for weeks before I bought a 1/2 inch parting blade instead of using the flimsy blade that came with the lathe, and it was night and day. I also learned to run coolant or even a dribble of cutting oil, brass will grab on you when the chip gets long.

For hole spacing I did it a bit differently, I drilled the holes in both rings while they were clamped together as one piece, then separated them. That way any error in the spacing shows up in both parts equally and they still line up. Worked fine on a 4 bolt pattern, might get dicey with more holes. One thing I'd suggest for the next version is thinking about how you'll retain those bearings. Mine walked out of the housing after a few weeks of spinning, so I ended up making a simple retaining ring with three little screws. Annoying to make but it fixed it for good.

Funny how the hole spacing is always the part that looks easy until you actually do it. I built a spinning display piece out of aluminum a while back and tried drilling both halves in separate setups on my little Emco. Even with a good four-jaw and a center drill starter, I was off by maybe half a millimeter on two holes and the studs would only thread in if I coaxed them. Ended up opening the holes on one ring slightly oversized so everything could find its own center. Not proud of it, but it spins fine and nobody can tell.

Since then I do what you did, everything in one setup with the chuck indexing, and I scribe a line across the face and chuck jaw first so I can always get back to the same position if I have to stop for dinner or lose track of which hole I'm on. Losing count halfway around a bolt circle is a special kind of annoying. On the bearings, one thing I ran into going bigger is that cheap sealed bearings sometimes have a bit of sticky grease from the factory that makes them feel rough at first. A drop of light oil and some spinning by hand and mine smoothed out after a few days. Worth checking before you blame your machining.

Post a video when the bigger version is done, spinning things never get old.

Those little threaded caps sound fiddly. When I made a matching set of studs and knobs for a brass gyroscope thing I got sick of fighting alignment on every one, and a cheap die holder that mounts on the tailstock changed everything for me. Cut a stub of stock, spin the die right there on the machine, and the threads come out concentric with the shank every time. Did you single point yours or run a die?

This is making me want to try somthing that spins too. I've only ever made little cylinders and a wobbly ashtray, nothing with parts that fit together and move. The bit I can't picture in my head is how you drill the holes through the side wall of a round ring without the drill wandering off the curve. Do you start with a tiny drill and go bigger, or is there some trick? Also what are you going to do with the next version, is it just for looking at or does it actually do something?

The spinning part is where it gets addictive, fair warning. Once I had a flywheel-ish thing turning true on my little 9x lathe I spent a whole evening just flicking it and watching. One thing to check on yours before the bigger version: give the assembled stack a spin and watch the studs, if the mass isn't even the whole thing will wander on the bench at speed. Mine did that with a heavy setscrew sitting off to one side and it took me a while to figure out what was making it hop. Swapped in an aluminum screw and it settled right down.