lazy susan type bearing? thrust bearing?

[sneakyimp]

J@GMFlint, I tried one of those 6" square lazy susan bearings that I bought at True Value hardware and i really liked the lateral stability and simplicity of it, but It doesn't spin as easily as I'd like and it's far too noisy. Those large-diamter ring-style turntables look pretty interesting.

Dick, I tried finding the sleeve bearings / bushings at my local hardware store and they didn't have any. Home Depot didn't have any bearings at all as far as I could tell so I went to Grainger Industrial supply. Thanks for the link on those bushings/bronze bearings. Those prices look good and I'll probably be buying some here shortly.

I broke down and bought two 2-bolt flange mount ball bearings and a 5" aluminum pulley with 1/2" bore.

jspatz1, thanks so much for the advice about the thrust bearings. I kind of thought they might work that way. The problem I'm having is that only a few of the flange bearings and pillow-block bearings I've seen have an extended inner race -- I worry about the lower thrust washer rubbing on the outer race of my flange/pillow block bearing and causing friction. Of course, it is a thrust bearing? Not really sure how it works. I suppose I'll have to just watch the dimensions carefully.

Thanks for the tip about the andymark hubs. I had seen some on a couple of the robotics sites I stumbled across but the lack of a set screw looks like trouble. I'm not really sure how I would couple these to the shaft. I'm not using keyed shafting or hex shafting.

Thanks for the tip about shielded/sealed bearings and yes I'm looking for very low friction. The bearings I bought at Grainger (which appear to be sealed) seem pretty stiff and the inner diameter is too small to fit the 1/2" steel tube I bought. They were also fairly pricey (@$16) so I think I might take them back and get some flanged bearings (and a thrust bearing!) instead.

The 5" pulley I bought looks like it'll make a nice hub. It's nice and wide and I've drilled 4 holes in it. I'm a bit concerned about the shape of it though as the part containing the set screw is precisely the shape that would scrap against the outer race of a bearing [see attached image].

Truly excellent suggestion about coupling to the speed reducer. I was considering trying to have the shaft machined to 6mm at the end. I'll figure that out once I've costed out the options. Thanks also for bushing suggestion, I'll probably get one of those recommended by Dick.

Tom, thanks for the drawing! And thanks for the suggestions about pulleys and belts. I had originally looked into that and decided that it was going to be difficult to get spin ratios high enough. I probably need 20 or 50 to 1 unless I want my entire song playing several times per second. That's pretty tough with pulleys.

Thanks for being sensitive to my inability to key the hubs and bearings. I'm going to look for some flanged bearings tonite and see what I can find.

I'll also be looking for shafting that will actually fit into the tolerances I get from grainger. Is it safe to assume their 1/2" shafts will fit into their 1/2" bearings or do manufacturers expect customers to machine these parts after purchase?

EDIT: Forgot to attach picture of my hub. Note the set screw bulge and the holes I drilled.