Awesome fabrication !!!!!!!
My process is reversed (sanding drum over adjustable height table http://www.routerforums.com/tools-wo...ss-sander.html
Feeding stock against the direction by hand gives inconsistent results. With direction makes missles. Currently tinkering with feed solutions. Controlled feed rate can be achieved with resistance to slow the missle or motor driven against sanding direction.
Resistance to prevent missle can be fabricated with compression springs providing downward pressure on a fabricated yoke holding bearing for rollershaft on each side .
I plan to use a feed constructed from a canniblaized 3-wheel bandsaw. It has VS control and gearbox with attached to motor I will fabricate a drum from stacked 3/4" MDF discs and wrap it sprially with 1/4" thich 4"wide adhsive backed Neoprene from Grangers my tinkers supply store.
I think your rig would be most useful with the overhead stop bar as the benchtop belt sanders are used
Pray for inspiration.
Learning is an exciting adventure