On Thu, Apr 26, 2012 at 5:16 PM, John Ferrell wro= te: > The drive hub looks like it might be a ribbon drive assembly. I have > seen those built with two flat motors in the assembly that are > mechanically connected. That may sound inefficient but if the part is > outsourced the part is bid to a spec and implementation is cost driven. Hi John, I'm not entirely sure I understand what you're talking about. Is it the metal bit on the output shaft? The top of that connects with an arm that moves the door, and there's a plastic flag in the middle for an optical interrupter. I've wondered if the metal part itself is some sort of safety clutch in case someone pushes on the door. I haven't figured that out yet though. Josh --=20 A common mistake that people make when trying to design something completely foolproof is to underestimate the ingenuity of complete fools. =A0 =A0 =A0 =A0 -Douglas Adams --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .