started to make one myself, then had a look on evilbay and found one at a machinery warehouse in Adelaide. A Chinese made pneumatic/ 240v automatic changer, cheap at $1200 incl gst and motorcycle adaptors. If you were a bike shop changing tyres all day every day it may not be the best, however i have had it for over 18mths and it gets used a hell of a lot and hasnt missed a beat. i know it seems like over kill to some, but i do a lot of wheel building and change tyres regularly, and it has more than paid for itself. I have worked in bikeshops where they have paid up to $5k for their changers.