Simple Shuttle

I found this alu profile at work and wanted to make something with it.
The profile is custom made, but you could make something like it yourself by mounting 2 U profiles at an appropriate distance.

The original shuttle is made of heavy duty steel.
I wanted something lighter and more modifiable.

All holes are 6mm with a snug fit, except the center top one,
it's 8mm to fit the rod I removed from an old scanner.

The whole assembly has about a millimeter play in it in all directions but its motion is very smooth.

The most interesting bit of this thing are the small elevations around the bearing bolt holes. They remove the need for washers.

I intend to attach the belt that will move the shuttle to the
center bolts so that the belt runs in the center channel