MakerBlock is building a 3D printed clockwork spider, and he’s experimenting with printing his own gears. He’s discovered a bunch of tricks for getting 3D printed clockwork to work (he’s also discovered a bunch of stuff you shouldn’t do!), and he’s documenting as he goes.
Don’t reinvent the wheel… or gear. The gears in my original designs were very very home brew, and it showed. I just created a flat cylinder and extended a bunch of small cubes off the edge. You can build a gear such as this easily in OpenSCAD, but using the “module” command makes it SOOoooooOOOOOooo much easier. 2 However, there was a lot of trial and error for me in getting the length, width, and space between the gear teeth properly proportioned. For my second revision, I designed the gears over from scratch using MCAD, Greg Frost’s Involute Spur Gear Script, and cbiffle’s Spur Gear Fitter Script to create gears that meshed well. Yes, it is more work to learn how to incorporate others’ works in your own, but you also get to benefit from their knowledge, experience, and expertise. You’ll also save time by not having to print a bunch of crappy gears that don’t work. ;)
(via Make)