A $500 difference adds up when you need 4 of them, that adds up to some serious cash. My machine will mainly be cutting wood and sometimes aluminum and brass. I of course want the best that is necessary. Below is a link to the base machine frame that I have built.
Thanks for the info Dan13, I didn't know about backlash concerns for larger diameter rolled ballscrews. I think I will need a larger diameter so ground is probably better. I notice that lower grades are better too, so from one site they are C7 and cheaper, but the other site is C5 which is more expensive. That site does do the machining for me though, so maybe the higher price will even out over all.
Thanks for your help.
Barry