This Strandbeest is ready for the security line at a security-conscious high school. Like see-though backpacks, its clear polycarbonate parts let you see everything that goes into the quirky locomotion mechanism. Despite having multiple legs, if you analyze the movement of a Strandbeest it actually moves like a wheel.
For us, it’s the narrated fabrication video found below that makes this build really interesting. Hackaday alum [Jeremy Cook] has been building different versions of [Theo Jansen’s] Strandbeest for years now. Strandmaus was a small walker controlled by a tiny quadcopter, and MountainBeest was a huge (and heavy) undertaking. Both were made out of wood. This time around [Jeremy] ordered his polycarbonate parts already cut to match his design. But it’s hardly a walk on the beach to make his way to final assembly.
The holes to accept the hardware weren’t quite large enough and he had to ream them out to bring everything together. We enjoyed seeing him build a jig to hold the spacers for reaming. And his tip on using an offset roll pin to secure the drive gear to the motor shaft is something we’ll keep in mind.
In the end, things don’t go well. He had machined out a motor coupling and it ends up being too weak for the torque driving the legs. Having grown up watching [Norm Abram] build furniture (and houses) without a single blown cut or torn-out end grain this is a nice dose of reality. It’s not how perfect you can be with each step, it’s how able you are to foresee problems and correct them when encountered.
Lovejoy couplers
Ha, hopefully you’re right, as I ordered a few earlier this week!
Thx for the writeup Mike!
Norm Abram is superhuman. That’s why they can’t show the tearout that you’re looking for.
Strandghost as a name
Ha, nice!
Is it just me or is there something off in the linkage lengths? The main stride of the leg seems to slope up from the first point of contact instead of being mostly parallel to the floor as seems to be usual in Strandbeesten.
You know, I think you’re right. In my previous versions I had the bottom gear connecting linkage connected on a nonexistent joint in this model. It worked well, but someone pointed out it didn’t match up with other ‘beests, so I put it on the joint I see here.
I’m guessing I based my original prototypes on an earlier Jansen design that doesn’t quite work the way I have it. Shouldn’t be too hard to fix for rev 2. Thanks!