Hi Ray
I see a lot of concern being expressed about the cost of the angular contact bearing blocks. Since these were / are intended for use in precision machine construction a lot of the cost is not in the bearing but in the machining of the block. The block - or at least the better quality ones - will ensure that the shaft lines up parallel with the mounting face. This is worth it only if used with a floating block at the other end AND if the two blocks are mounted to ground flat faces known to be in the same plane as each other.
With home brew machines this is probably not going to be the case due to the method of construction and the methods used. Thus a lot of these precision bearing mount properties are wasted as the bearing mounts have to be shimmed to bring the bearings - shaft and motion travelled into alignment. So why not make your own bearing blocks assuming you are going to have to make adjustments to the mounting on assembly rather than pay through the nose for precission that was intended to give rapid bearing changes on production machines. Suitable bearings can be found in the attached see page 53 and onwards.
http://www.skf.com/files/151315.pdf
The cheapo suppliers have this bearing series on sale for arround $10 genuine SKF ones will cost more. I have purchased a number of these in non branded form and found that there is enough preloading built in to give no measurable movement in the radial direction and still have reasonable free movement in the axial considering mine have all been 2 RS types. With the pre loading set by the manufacturer the double row angular contact bearing is easy to mount.
Yes I know I don't like giving my money away - my excuse is that I have retired so am cash poor but time rich but I still don't have enough of the latter!
Regards
Pat