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Unread 04-10-2010, 18:15
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Re: lazy susan type bearing? thrust bearing?

Quote:
Originally Posted by sneakyimp View Post
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.
Here are some aluminum hubs that might be suitable http://www.andymark.biz/hubs.html AndyMark has many hubs, bearings, shafts, collars, and bearing holders that might suit your needs. FRC robot builders rely heavily on AndyMark for parts.

For a cheap shaft coupling, with the low torque you are dealing with, a short piece of stiff rubber tubing and hose clamps might be suitable. The flexibility will allow for a some misalignment in your assembly.

Be careful of "sealed" vs. "shielded" ball bearings. "Sealed" bearings have some friction from the seal and are not free-wheeling. "Shielded" will keep out most dirt and debris, but are low friction. I assume with a wind application you are looking for as low friction as possible.
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