Assembling Rollers.

For “Legs” use 1 inch 5/16 bolt, 5/16 nut and 608Z ball bearing. Insert bolt into ball bearing and into the rollers hole. Depending on quality of your print you may need to screw bolt into the hole.

and fix it with nut

For middle part you need 1 1/2 inch 5/16 bolt, 5/16 nut and 608Z ball bearing. Insert ball bearing and position it so you may insert bolt (again you may need to file the hole or screw in the bolt)

and fix it with nut

And do the same for all ball bearings…