I just drilled some holes, slipped them in, and used snap rngs to hold them in place.
http://www.cnczone.com/forums/attach...tachmentid=647
When I bought these, I thought it would be a lot cheaper than THK's. I spent about $70 for the 4 bearings and 2- 18" SS shafts. Since building this, I managed to find some 18" THK's for about $50. But it can take months to get good deals on Ebay.
If buying these new vs THK's, I'd get supported shaft, so no end supports needed, And integrate the bearings into the axis to eliminate the pillow blocks (They fit in standard size holes, and you can get adjustable ones to account for misalignment). This would probably still be a bit less than THK's, if purchased new. But with Ebay, if I were starting over, I'd go THK every time.