Steam Donkey, No, the board doesn't slide it's a tight fit to the table. I had to add it because I had originally built the unit for a much larger drum and rather than take it all apart I just added the extra table.
This was a good move as I was able to force slide it back and forth under the sanding drum to true it to the drum something I couldn't have done with the fixed table.
The wood is hand fed, single pieces or multiples depending on the width being sanded. The sewing machine motor isn't really strong enough and if I try to take too much off at one time it will stall. I can remove about .005 with each pass.
I've kicked around the idea of making these as a commercial venture but the cost to get going at it would be more than I'm willing to chance. I would do the sides in fiberglass reinforce resin and use thruss bearing set into the side frames rather than the pillow blocks. As I said, the motors would be another matter to deal with. It was fun to build.