This is an extremely cool project to make a coffee table that walks around on legs made from wooden linkages (Strandbeest style).

The linkages were designed using a genetic algorithm to “evolve” the best linkage. Legs were scored based on walking speed, clearence and material use. And also on which legs moved most smoothly and horizontally during their walking cycle (minimises slippage and bobbing).

Then the author eventually got a CNC machine, and suddenly gained the ability to actually make these linkages.

Ended up using laminated bamboo, which is very strong and stable. Good for high precision wooden parts. (and its light)

Using a fully featured CAD package which could handle any point in the walk cycle was important for getting clearences right.

The separation between legs houses the electronics, motors and batteries, and increases the turning moment (so it can go round and round better). Not something I would have tought of!

Each leg is on the ground for 1/3 of its period, so you need 3*4 legs for stability. That’s 6 on one side, 6 on the other. Each 6 is driven by a single motor.

Parts were produced using 3 axis CNC since it rquires a lot of precise linkages. Features were needed on both sides of the parts, which was realised by machine two separate sheets of mamboo and then gluing them together.

Metal parts were made similarly, and the curved belly doors made by kerfing and bending the plywood and affixing to hinges.

I think a big part of the success is the fact he topped the fancy walking table and the TV console with the same surface so they go together very well.

It’s very cool how a well designed and well-made linkage can be pushed around by hand and just ‘walk’ with you.

Motors driven from a step-up/down converter whose output voltage could be set to any value using a PWM signal from an arduino, which would recieve the remote control. The voltage converter modules also had a max current which allowed you to have a max stall torque, and thus some safety.

Closed loop motoro control in the arduino, so the legs could target any speed and position, independent of load!

Final step was hooking it up to a nunchuk remote, and now it can walk around and bring you your drink! Cool. Not very useful, but nifty!

This is very nifty!