Alan Federman built our Da Vinci Reciprocating Gear project in MAKE Volume 24 (video above). He has a number of other cool working Da Vinci models, built in wood, on his YouTube channel. You can learn a lot about the basic mechanics of gears, cranks, screws, and other simple machines by looking at these devices in action. Below are his screw cutting machine, followed by his file forging machine (it hammer-forges grooves in metal to create a file).
More: Check out our entire Mechanics Archive
Check out MAKE Volume 24: MAKE blasts into orbit and beyond with our DIY SPACE issue. Put your own satellite in orbit, launch a stratosphere balloon probe, and analyze galaxies for $20 with an easy spectrograph! We talk to the rocket mavericks reinventing the space industry, and renegade NASA hackers making smartphone robots and Lego satellites. This, plus a full payload of other cool DIY projects, from a helium-balloon camera that’s better than Google Earth, to an electromagnetic levitator that shoots aluminum rings, and much more.