Hi dazp1976. Thanks for the reply. In the end I did use plain and spring washers, as they were easily available. Not the cheap silver springs, as they go flat. I used tensible bolts for bearing cases and nut cases, but not for rails, as they are quite expensive. Will upgrade in the future if necessary. So problem solved for now. The cnc is working fine and did quite a few medium sized carving with it.

I ran the machine 5 hours straight at most until now, but there is a job that is on my mind, a 4x2.5 feet carving, which will be a table top with some glass over it. Anyway, the job will take apx 11 hours to carve, and
I have no clue for how long can this cnc machines function without a break. For a 5 hour cut, the x motor which does most of the work, gets quite hot, like you can hold your hand on it for 5 seconds max, but I did read in some previous posts that it is quite normal. It is nema 34 1200 oz.

What do you think? Should I break the job in two parts or do it in one go? Did anyone used the cnc for such a time or longer?