Here the roller handle and rollers are spread out. The aluminum strip on one side
has a #4-40 press nut installed to catch the end of the #4-40 screw shown. The
spacer is 0.25 inch outside diameter by 0.5 inch long. The screw clamps the ends of
the spacer tight and it forms an axle for the actual rollers. The white pieces are the
newest and have been cut from a polypropylene cutting board found among kitchen supplies.