This may be old news to some, but after seeing Theo Jansen’s “Strandbeest” walking contraption, I think I’m going to try to build a version of it. Possibly my version will be built with parts from my “giant hexapod” (relatively giant) remote control ‘bot that never really walked that well. I doubt mine will be powered by wind, but a few windshield wiper motors might do the trick…
After some study of The original mechanism, my thought was that as a mechanical engineer, it should be within my mental capacity to design my own four-bar-linkage to accomplish this task. Unfortunately, after some mental gymnastics, and a rough sketch of Draftsight, I realized that this might be more difficult than I imagined.
Using six legs timed correctly might be possible, but four legs would seem to just scrape back and forth on the ground unless there was a more complicated mechanism. Fortunately, I found that someone else had a very similar idea, and had published his work here. Here’s a really cool animated GIF of it walking around:
The linkage lengths for Theo’s original “Beest” are published here, which is great since it apparently took a computer quite a while to crank out the proper dimensions. This guy even wrote a 172 page thesis on the subject, so I don’t feel so bad about not being able to just come up with the linkage in my head.
The writeup on the beest to the right, goes one step further than the original explanation (though not quite 172 pages worth) providing drawings of each mechanism. They are not in CAD format, so I can’t just have my CNC router crank them out, but very cool nonetheless.
If you’re still having a hard time getting your head around how the four-legged beest walks, here’s a really cool simulation of the mechanism. Although I couldn’t read the Sweedish instructions, I did find the term “strandmonster” enjoyable.
If I do build a walker, I imagine it will be some combination of both of these machines. Alternatively, maybe I will make a small one similar to the animated GIF, then scale it up later. Or maybe I’ll get bored and move on to the next project – it seems like I was working on a mechanical clock recently… Unfortunately, I don’t seem to have enough time (or money) to build every idea that I have.
Hopefully this page will serve as a good reference for the Strand Beest, translated “Beach Beast,” or possibly ” Beach Monster” device. I had to do quite a bit of searching around to get all of this information together.
Edit 5/27/2013: Thanks to A.E. Veltstra (comment below) for clearing up some language confusion that since corrected on this post!