Barry,
Had a chance to look at the ball screws you had kinks for. Gee's only about $500 difference. From what i see in the pictures the ones from homeshop cnc are rolled screws and have preloaded nuts.
You can find a lot of info on ball screws via the web. Heck, just go to Nook or NSK sites and you have all the reading you could want!
I noticed that they offer machining of the ends. I took me 6 hours to machine the two ends on one of the ball screws ( grind and then machine). Went thru 3 carbide cutters ( 3 sided insert). It's a PITA. SO you may want to
realy consider farming it out or using a favor or two up.
Back to the practical side of things:
1. Ball screws, as a system, ie; type, mounting, size, grade, etc act as a system which is application dependent.
Since the screw is a major component of movement, you would idealy like the best. Practicaly speaking ,
as long as the screw satisfies the application ( which you have not defined ), then it may not make any sense to
spend money for quality not required.
2. You can spend a small fortune on bearings and they play an important part since because they are part of the
system.
3. You can have the best system components, but, if the installation is lacking, then you will downgrade how the
components will function.
So what are your thoughts now on the matter?
RICH