When I bought my cnc machine, the guy gave me 5 of the round feet in the attached picture. But there are 6 adjusters on the machine. Also, I think he said there should be ball bearings between the feet and the adjusters on th e machine. At the time, I just put the machine down on it's adjusters but it was really too low to have the coolant tank in the proper position. Can someone fill me in on what I'm actually supposed to have and where I might get it?

Thanks.

Edit: By "Ball Bearings" I really meant "Ball Brearing", as in a single large steel ball.