Rollingstep Walker

thingiverse

We've already explored various walking mechanisms using a single rotating crank and connected bars with hinges. One such design is the Klann linkage, while others include Theo Jansen's Strandbeest, Chebyshev Lambda / Plantigrade, Ghassaei, Strider, and Trotbot. I wanted to experiment with another approach, utilizing a common 4-bar linkage but with an unconventional twist - the foot link is shaped so that its contact point isn't constant during movement. As the vehicle advances, different parts of the foot make contact with the ground, mimicking the rolling step technique used by marching bands, hence the name. A potential vehicle could be propelled using eight legs. I printed two halves of a vehicle and mounted them on an acrylic plate. For the electric components, I employed 2 DVD spindle motors, 2x 18650 lithium batteries, an Arduino nano, HC-05 bluetooth, and a robot controller board with 2 H-bridges. The linkage bar lengths and foot shape haven't been optimized yet; this is merely a first prototype. Feel free to modify it and discover a more effective design (and perhaps conduct thorough research and publication). To print half of the vehicle: * Topframe: 1 piece, all holes are 3 mm in diameter * Frame1: 1 piece, all tapped for M3 screws * Frame2: 1 piece, all tapped * Foot: 4 pieces, 3 mm hole * Bar: 4 pieces, 2 mirrored, 3 mm holes * Rocker: 4 pieces, 3 mm hole * Crank: 2 pieces, 3 mm hole * Gear1: 1 piece, 2 mm hole for motor shaft * Gear2, gear3, gear4: 1 piece each, 3 mm hole * Gear5: 2 pieces All screws used are M3 with lengths of 40mm, 25mm, 20mm, 12mm, and 10mm. After printing, I need to clean the screw holes by drilling and form threads using tapping, as well as several hours of whittling for the gears. Only "crank.stl" requires support; however, I included "crank_support.stl," which already includes manual supports (which stick somewhat to the part - I removed them with pliers).