This just illustrates more issues with the bottom tread-feeding from a stack. I think I could probably get it to work, but I'm thinking of trying something different: using a bar or something to push one disk off the stack, either from the bottom or from the top. If it's from the top, then I have to keep moving the stack up; I don't really want to do that as I'll have to use more motors for that. However, I think it would be fairly easy to do: one motor to raise/lower the tray, one motor to push the bar/dispenser/whatever across the stack, and a touch sensor to determine when the stack is in place for the bar pushing. From the bottom, I'd have to figure a way to keep the stack higher because it's about 3 DVDs per 1/3 height bar, so the propensity of using a bar would be to take 3 at a time. Yeah, I'm gonna try taking from the top of the stack. Since I only have 4 outputs, I'll have to make sure I don't do anything which requires >2 motors on the discard stage.