Making a “Beest” Leg Linkage System

First of all, thanks to Theo Jansen, then Dominique Studer as they have done much of the “kinematics” work needed for the contraption that I intend to make, a four-legged walking ‘beest.  Regardless, what I am working on is a definite departure from either of these machines.  As I’ve been discovering, making something like this in real life is a definite challenge, whether or not you have some interesting examples to help inspire and guide you.  Here’s a video of me doing an early test of one of the legs:

Obviously it still needs some work. If you think it’s easy to even get to this point, be sure to check out the time-lapse video and pictures of the manufacturing process after the “read more.”

What I built was most directly based on a scaled-up version Dominique’s linkage design (without the gears so far), which, in turn, was based on Theo Jansen’s ‘beest.  Dominique’s linkages were, rather unscientifically, divided by 5, then arbitrarily turned into inches.  Given the scale of the original device, I think his ‘beest was in millimetres.  My ‘beest leg turned out pretty large as can be seen in the video, but this really shouldn’t be a surprise, since I did redraw them. If you’re interested, Here is the CAD file that the linkages were made to.

For the pivots, I used 1/2 inch PVC pipe, and stuck on elbows and tees until I could get something better to restrain everything.  The holes were drilled with a 7/8 inch spade bit in the middle of the wood, 1 inch from the edge.  This worked out nicely.  some of the edges were milled down as shown in the video, and even more cuts were taken later for the long joints as some tight angles had to be compensated for.  The wood used was 1×2 inch “white wood” from Lowe’s.

If you’re wondering why I had to mill some of the ends, what I did was I cut the edges in half in order to make them as thin as one piece for the whole assembly.  This was done for both “triangle” pieces, so they could fit inside the other linkages.  As seen in one of the pictures, I glued the top triangle, which helped simplify assembly.

bg_strandbeestsTo make the driving linkage for my eventual walker, I think I will use 1 inch PVC pipe and 1×3 inch wood to give it a bit more strength.  The way I envision things working out (see this interactive animation of the static picture to the right) there will be four linkages connected to the crank mechanism.

If I am able to build the “walker” I’m imagining, I think I will call it a “MountainBeest.” I’ve got what I think is a pretty clever way to transfer power from a windshield wiper motor to the crank assembly, or maybe I’ll use some other form of stored energy…  Be sure to check back, or better yet, subscribe (see ways in the upper-right of this page) to see what happens!

  1. It’s an interesting contraption. Can’t wait to see all four legs put together and tried!

    It looks like the torque requirement for the motor is very uneven throughout the cycle – do you think it may be wise to use a flywheel to assist in the peak load times? Or perhaps use an oversized motor and crank the current up as the leg is just about the hit the ground, which looks like the point at which the torque requirement goes up tremendously.

    Good luck with the Beest!

    • Thanks! I’m definitely looking forward to it walking too, so I’ll keep my fingers crossed!

      A flywheel or some other way of balancing the load may be a good idea. Hopefully when the legs are all there maybe they can provide some “evening-out” capability.

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