Big cheap bearings?

[Chris64]

Anyone know where I could run across large bore bearings (around 2.5"-3")? They don't need any type of taper as they're only holding weight on a single axis. I was thinking maybe something like Truck Axle bearings bight be a good size (not really sure though) and certain;y string enough...not sure on the price though.

[zabink]

Chris,

What type of bearing? Radial or linear?

[Chris64]

Sorry, radial I guess. Just a standard round bearing right? Linear would be more like something for a cross slide...not that (but, any sources of these while we're at it?)

[zabink]

Chris,

The cheapest bearing you will probably find with that size bore is in fact the pillow block bearings for axles. The ones in the links below run from 40 - 90 us dollars.

http://cgi.ebay.com/2-1-2-Bore-4-BOL...QQcmdZViewItem

http://cgi.ebay.com/SealMaster-Pillo...QQcmdZViewItem

Depending on your application, you could use plain oiled bronze flange bushings or ceramic bushings. The friction is not that bad depending on the surface of the rod. You can get these for about 6 us dollars a piece. However, it all depends on the application. RPM's, materials etc. If I knew a little more about the application I could recommend specific products.

The cheapest new set of linear rods and bushings you are likely to find is through VXB bearings.

http://www.vxb.com/page/bearings/CTGY/LM

Again, without knowing the application you may need linear rails and bearing blocks. The cheapest source for those will be e-bay.

Hope this helps and let me know if I can assist your further. You can just respond to the forums or contact me via www.cncroutersource.com. My email address is keven@cncroutersource.com.

Regards and Happy Holiday

[2muchstuff]

Where were you two weeks ago? I trashed a bunch of them in that size. I may have a couple left but I think the bore might be in the 4 to 5 inch range.

[Chris64]

I just thought of the idea yesterday...sorry (lol)

I've been looking at auto parts places and they do have complete bearings (looks like a sealed bearing, but not sealed) for truck axles. They're about $60 each.

For what I'm doing I think that may even be overboard. The assumption is that if you have a 2-3" bore, you're supporting a ton of weight. I just need the through bore. I was considering just trying to find some small cheap ball bearings (the balls themselves) and just turn the race right into the case and the spindle. Or even just use three small bearings that the spindle can ride on. This solution is just somewhat "cheesy" for this app IMO.

2muchstuff, About those 4-5"...I wouldn't mind hearing a little more about those.

[Geof]

Originally Posted by Chris64 ... I was considering just trying to find some small cheap ball bearings (the balls themselves) and just turn the race right into the case and the spindle. .....

This will not last; you need hardened material because the balls make contact over such a small area.

Truck axle bearings are probably overkill capacity wise but might be the easiest approach.

[2muchstuff]

I'll dig them out, measure them, see if there is a number on them and get back to you.

[Chris64]

I ran across a the jackpot. A place called Industrial Liquidators had a pretty big assortment of large bearings. They were all under $25. That said, I'm going to experiment with different ideas over the big weekend. If my idea works (a big IF), it has potential to be a resellable product. So basically I'll need to be able to work with "off the shelf" parts.

I'm going into the garage right now to try my three bearing theory out.

Plus I need to figure out how an easy way to create a spindle...specifically how to add a gear (or some method to control it's rotation). I'm going to try to cut through a gear I have, then I could potentially either weld it in place or weld and turn a mount and screw the gear to the mount.

Anywa, my ears are still open for any good idea's or thoughts. Thanks.