The new machine is an improvement on the original one. Primarily, it's more compact. The first machine from way back was an experiment and I never went back to optimize it. With this machine I already knew that the concept worked so I focused on trying to make it as compact as possible.
The machine works by having a magazine of dominoes that is dragged along the table and a slider that moves back and forth sliding one domino out of the magazine at a time. All along, the machine is driving forward, which causes the released dominoes to be spaced out.