I've had several Kirbys over the years, but I must admit that when I stumbled on this group it wasn't for vacuuming. I'm building a small CNC machine that needs a dust extraction system. In my experience a Kirby motor+fan (even at low speed) provides more grunt for less power consumption than any other option I looked at. So I've dug up an old Kirby G5 with a failed switch, and I've come here to (re)learn the ins and outs so I can wire it up without the switch, drawing air and dust directly from a cyclone separator; so far so good.