The Mistake (Screwless Klann linkage)

thingiverse

No screws, no printed gears, print-in hinges, what could be wrong? Turned out: many. This is an experiment on making a walking robot with no screws. Gluing might be needed anyway. I think the strength (and weakness) of the connections are influenced by the z-axis wobble of my printer, it created corrugations that add grip (this is how I print for 4 years). Don't know if printed in a perfect printer, maybe everything will come apart if not glued. The walking mechanism is based on the Klann linkage. Each side (4 legs) is mounted on a bogie which is connected to a differential arm so supposedly it can navigate uneven terrain better than a rigid body. The hinges have 0.25mm clearance, it prints fine on my printer, it can move well after initial force-cracking, much exercise, and adding lubricant. The space within the frame is just enough to put a 2x 18650 lithium battery holder. The motor is N20 DC motor with gearbox rated at 6V, 200 rpm. https://www.youtube.com/watch?v=FSGZGtzG4Y4 Parts: linkage x8 frame_outer x2 frame_inner x1 + 1 mirrored frame_mid x1 frame_top x1 frame_front x1 pinholder x2 pin x2 difflink x2 diffbar x1 crank_motor x2 crank_triangle x2 crank1 x4 crank2 x4 crank3 x4 After printing and assembling, I realized that there is a mistake in how the connections are designed... Print this if you want to re-discover it. Otherwise, try the next version if you are interested: https://www.thingiverse.com/thing:4971253