Actuation time, precision, repeatability, size, aesthetics, control methods, etc. But, search the forum, there were some old threads with alternative transports. One guy cobbled one together with lego robotic parts IIRC. IMO, if you can't swing the ones made for the job then: a) anything is better than no transport. (e.g manual transport) b) any automatic thing is better than a manual transport.
11/22/13 at 7:36pm