Amazing advice guys. Thanks.
I'm definitely going to try Dick's suggestion with oil-impregnated bronze
sleeve and
thrust bearings. They are just too cheap not to try and the argument about corrosion is a really compelling one. I also expect they'll be very quiet.
I can also get the
flanged ball bearing and a
thrust ball bearing for under $10 so it's definitely worth getting those too for comparison.
Dick's also right about enco's drill rods being cheap. They have product #409-0029 which is under $6 for a 3-foot length. Tolerances are +/-.001 so I'm not sure if they would fit with some of the bearings/bushings I linked above. Those tolerances are better than the +/-.002 that McMaster lists for #86705k411 Wear-resistant stainless steel (type 410, $6.50, 12" long) but it'd be nice to order everything from one place to maybe save on shipping. Plus I don't need the full 3' length. Any thoughts on whether I might get away with these tolerances for the bearings I plan to use?
If the shaft tolerances are important, I might forego the stainless steel shafting for the 12" Unhardened Precision Steel Drive Shaft #1346K17 (about $7). OR I might splurge for the 12" Easy-to-Machine Stainless Steel (Type 303) Precision Ground #88915K221 (about $13). The extra $6 is pretty cheap insurance to get something that is
* precision tolerance
* stainless steel
* easily machined
Since I'm using set screws I was wondering if I should maybe use a D-profile shaft (round shaft with one flat side). The have a 12" Type 303 Stainless Steel #8632T87 for $16.40 and a 12" AISI 1045 Steel #8632T7 for $9.27.
jspatz, Thanks for the additional info on the thrust bearing. I know how they work, I'm just a bit concerned about the diameter of the lower thrust washer and the shape and diameter of the races of the flanged ball bearing upon which it rests. I'm guessing it's bad if the lower thrust washer contacts the outer race of the flanged bearing. And what do you mean about a tapped set screw hole? Am I to understand that a local hardware store might drill a threaded hole in some arbitrary hub for $5 so I can put a set screw in it? That would be awesome as then I'd only need to find some hub stock.
It's beginning to look like I can get all my bearings, bushings, shafting, and shaft collars for under $30. I hope to place an order tonight or tomorrow on this. I hope you guys might weigh in on the shafting before I do. Is stainless important? Is drill rod enough or do I need precision shafting? Should I get D-profile or regular shafting?
THANKS so much. I'm getting pumped for this.