I’m going to try this again. Hopefully it won’t need moderator approval?
So grateful for the input. Really sorry for this long message, but I’m still confused about a couple of things – mostly the details of how these bearings and bushings couple together and how to make sure torque is transferred from the turntable to the shaft and finally to a speed reducer.
Jim, I’ve attached a drawing of your suggestion as I understand it. I mount a pipe or tube to the my chassis and fit in its end a flanged bronze bushing, flanged plastic sleeve bearing, or flanged ball bearing in the top end of the tube. It’s obvious that the shaft goes through the middle of the bushing/bearing and that the bushing/bearing goes inside the pipe/tube and that the flange needs to be large enough to it doesn’t fall down the tube, but I don’t really understand:
How does the bushing/bearing support the weight of my turntable? In my attached drawing I have the hub resting directly on top of the bushing/bearing but this might not work unless the bearing has an extended inner race that’s higher than the rest of the bearing. Might I need a washer or shaft collar? Some kind of sleeve?
My experience with the lazy susan suggests that scavenging a hardware store will hardly result in tight tolerances. It’s probably easier to pay a little more from sdp-si.com or mcmaster.com if I can be sure I’m getting what I need.
I really like the image you sent with the bearing. I can see that the inner bearing race is slightly taller than the surrounding bearing parts which might permit it to directly support a turntable, perhaps with a washer or hub as the actual point of contact. The Forstner bit tip also seems really helpful. Am I right in thinking I could sink a flanged bearing directly into a hole drilled in plywood by a Forstner bit? Perhaps shimmed with a little tape?
Tom, I really like your idea of using a flanged ball bearing, perhaps just dropped into a piece of plywood drilled with a Forstner bit. Any thoughts on using a tapered roller bearing for this? At $10 delivered with a 3/4" shaft, these seem like the ideal top bearing to me but I don’t really know how to mount it to my chassis (Forstner hole?) or how to rest the turntable/hub on it. Suggestions welcome. I’ve done a drawing for this too. Also, what about flange mounted bearings? Might any of these mounted bearings work? I’m thinking these options would help me skip the whole pipe/tube finding step.
Dick, if I could get the tapered roller bearing AND the hub for $20 that would be a dream come true. I’m wondering, however, if the hub can apply torque to a shaft using those parts? If I’m not mistaken, it looks like that hub spins freely on the shaft. I need my turntable to forcibly rotate my shaft, transferring torque to the speed reducer. Please let me know if I’m misunderstanding something here.
Those Magliner bearings look really good (and cheap). The fact that they are sealed is GREAT. It was way too easy to get sawdust in that lazy susan bearing and this thing is likely to live outside in Los Angeles which is extremely dusty. Unfortunately, the page doesn’t specify the bore diameter. Also, still wondering about how to get the turntable/hub to rest on the inner bearing race without rubbing up against the outer collar or bearings. Washers? gasket? shaft collar?
I think we’ll have this bearing thing affordably sorted momentarily here if you guys can help me understand the mounting and coupling of these bearings. The Forstner bit hole looks pretty promising for some of the more affordable bearings and the flange-mounted and pillow block bearings are a more expensive but elegant-looking solution.
Again, sorry for the length but here are a couple of final things I’d like to ask.
COUPLING THE SHAFT TO MY TURNTABLE TO TRANSFER WIND POWER TO SHAFT
Aside from the question of how to rest my turntable on a bearing’s race, I’m wondering where the heck I can find a suitable hub/flange mount to couple my turntable to the shaft. I found these universal aluminum hubs which are perfect except they only fit smaller shafts. Except for this one (which doesn’t look particularly stable against lateral forces), I haven’t had much luck finding hubs for shafting over 3/8" – which is a problem if I use the tapered roller bearing because those are all for 3/4" and higher shafts. Threaded hubs, splines, and keyed shafting are probably not an option because of my inability to machine the shaft or the bearings. Ideally this would use a set screw or clamping mechanism and would have all the holes already drilled in it.
COUPLING SHAFT TO SPEED REDUCER
I’ve seen shaft couplings and I’m guessing this is what will be needed to couple my shaft to the speed reducer, but they seem so pricey – $10 at least for such a simple thing. If anyone knows of some alternative, I’d love to hear it. Also, the speed reducer looks to have a shaft diameter of 6mm so we need to couple some larger shaft (10mm? 3/8 inch?) to it.