I became fascinated with the infernal machine as displayed in adds for the fall issue of DM. I know how it works but can not figure out what the tooth form might be to engage the 3 dissimilar size gears to the one 'idler' gear. Clayton Boyer has plans for a wooden version so I suppose he uses the original method of lots of play.
I also ran some simulations showing the thing can be made using a belt system with 2 axies and 4 pulleys but it would be much less eligant than brass gears.
Anyone have thoughts on the gear tooth form?