I have posted this question in the general metal working forum but thought it should be here as well so dont shoot me for double post.
I am looking at building my own cnc mill. I am looking at building the design that is in the plans section here at the zone. I plan to mill standard steel and aluminum for the most part. I need it to be accurate at least to the thousands. I am looking at different bearings and need your guys opinion. Do I use the flat rails or supported round rails or does it matter. Round rails I am looking at 20 mm for xy and 16mm for z. As for the flat rails what ever i can get a hold of for a good price I have found a set of flat rails the are hiwin egh20ca for the xand y and find something else for the z. What do you guys recommend for this supported round rails and open block bearings or the hiwin/thk type flat rail bearings? I am attaching pics of the rail types so everyone knows what i am talking about.