Wow, you can do this at home??? That is very cool. The Navy is hiring....right now, in the next room. Looking for civilians. They are trying to fill 60 positions.
Dave, is that the one with the magnet for leveling??? I spent the weekend with friends at hunting camp. One of them is a retired machinist that has a garage shop. We schetched out a tonearm that will look very cool. It will have on-the-fly VTA, length adjustment weight adjustment, and a lifting arm AND non of it can be seen....all hidden. AND, of course, it is a swoopy piece of art.
I just read through this thread and had a lot of fun! I was thinking about the concept of having the mass at the outer edge of the platter. Not that you should do this, but what about pockets drilled from the outer circumference towards the hub with a slightly downward slope. The pockets could be filled with mercury or ball bearings. As the platter picks up velocity, the weight would be slung outward. For start up, the weight would be at the center of the platter.
it's an interesting idea, but i'm not sure you'd ever get enough speed built up for it to work effectively. I really don't mind giving it a nudge. In fact, that's how you start and stop the Teres turntables. Very elegant solution, IMO.
I really like the magnetic bearing. I did a paper in college on future transportation and one section was on maglev trains. I think it is a brilliant way to support weight. By the way, we use many oil-impregnated bronze bearings at work. They really do a good job.
The magnet thing should be interesting. I'll be curious to find out if the vertical stability will be solid enough. If not, I'll install a ball bearing at the end of the shaft. The magnets would still remove a huge majority of the weight but I hope to avoid any physical contact.