Window Skylight Shade Rod, Pulley, and Bearing

I use this set to create my motorized sky light shades.

I have 4 pairs for each skylight window. The windows are angled so I use a rod on the top of the window to roll up the curtain/shade and a chain on either side to keep the shade at the same angle when rolled down.

The bearing is 8mmID/22mmOD and fits very tightly into the wall mount. Spacing below the race ensures perfect free spin.

The pulley fits a 4.5mm beaded chain. I derived it from http://www.thingiverse.com/thing:867 exte