Butcher saw V-wheels on e-Bay - can they be used?

[eesanopi]

Hi,

I'm in the proccess to acquire the components for my CNC router, I found this wheels in ebay:

http://cgi.ebay.com/V-Groove-Butcher-Boy-Saw-Table-Roller-Bearing-2-PCS_W0QQitemZ270289693212QQihZ017QQcategoryZ25374Q QtcZphotoQQcmdZViewItemQQ_trksidZp1742.m153.l1262

This kind of V wheels are used in butcher saw machines, they are real steel ball bearings and price is low, I think they are sealed, because they must be designed to work in the wet and dirty enviroment of a butcher shop.

What do you think about it?, Could I use this bearings in my project?

Any help will be grateful

[domino11]

Those bearings on first glance look to be a little small in diameter compared to the ones that are specified for the mechmate. Hard to tell without dimensioning. Also the V groove looks to be larger than those specified for the mechmate. The v bearings are probably one area that you would not want to deviate too much if you would like the performance of the design to be maintained. :)

[bradm]

Ebay page says these are "V" groove . 1 5/8" diameter, 3/8" core , 1/2" wide. Ball bearing center core.

BWC size 3 are 1.8" or so, just under 1/2" bore IIRC.

I agree with Heath, you may have trouble in a number of different spots: you'll have a lot less eccentric (if any) to work with on the Z axis due to the 3/8" bore. The diameter change will affect some of the clearances on the X and Y axis, although I can envisage a little grinding if it's too close.
Finally, as Heath points out, if that V is too wide (or not at 45 degrees), you'll have to re-engineer the rails, and that sound pretty scary.

[smreish]

This is one area I would not want to deviate from. The performance specifications on the real #3BWC or Superior Bearing equivalent meet some very critical criteria - namely horizontal thrust, and vertical gantry/y-car ride height.

The bearing diameter dictates the gap distance between the motor mount swing arm and the pinion. This vertical dimension does not like to be changed.

I would stay with the specified bearings in the package or purchase the appropriate ones.

[Gerald D]

This thread originated on the CNCzone:
http://www.cnczone.com/forums/showthread.php?p=527253

[eesanopi]

Hi,

I'm in love with the mechmate machine design, but in this moment myCNC project is limited in budget, however I was thinkin a lot in your opinions because in the future I'lll construct a mechmate, I'll go for original V bearings.

Thanks for your comments.