|Lego strider 01
We already know the Klann linkage, Theo Jansen / Strandbeest linkage, Chebyshev Lambda / Plantigrade, Ghassaei, Strider, Trotbot, and many more, which are all designs for walking mechanisms using single rotating crank and several bars connected with hinges. I tried yet another mechanism, using the common 4 bar linkage but with the foot link shaped such that the contact point is not constant. While the movement is advancing, different parts of the foot will touch the ground, like the heels and toes of human foot. This is similar to the rolling step technique used by marching bands, hence the name.
A vehicle could be propelled with 8 legs. I printed two copies of half a vehicle and mounted them on an acrylic plate. For the electric parts I used 2 DVD spindle motors, 2x 18650 lithium batteries, Arduino nano, HC-05 bluetooth, and robot controller board with 2 H-bridges.
The Strider mechanism might look similar to Strandbeest walkers, but it lifts its feet higher, allowing it to traverse rougher terrain. [Chen]’s little 3D printed version is driven by a pair of geared N20 motors, with three legs on each side. The ESP32 camera board allows for control and an FPV video feed using WiFi, with power coming from a 14500 LiFePO4 battery. The width required by the motors, leg mechanisms, and bearings means the robot is quite wide, to the point that it could get stuck on something that’s outside the camera’s field of view. [Chen] is working to make it narrower by using continuous rotation servos and a wire drive shaft.