Theo Jansen sandwalker

[Zolko]

Hello, may-be have-you seen these strange legged beasts that a Theo Jansen has produced and that seem walking :

phpBB [video]

well, I managed to model this (the legs at least, the most fancy part) in FreeCAD. Here an assembly of a single leg:

single_leg.gif (528.89 KiB) Viewed 43587 times

And here an assembly of many (many many) legs. This was done with variant links, meaning that it's the same assembly (of a single leg) that is inserted many times, with only the angle of the central handle differing, and set - using its ExpressionEngine - to the main assembly's variable, with offsets between legs. The rear legs also rotate in the opposite direction.

walker_15legs.png (474 KiB) Viewed 43587 times

And of course the animation of it:

[carlopav]

cool stuff here, i'm a big fan of Theo Jansen!
very nice movement indeed, bravo!

[Zolko]

cool stuff here, i'm a big fan of Theo Jansen!
very nice movement indeed, bravo!

thanx. All the files are in my example repo

[FreeCutter]

Really cool! And very interessting example to study details in order to learn!
That's what I did and came to these questions:

How have you actually done the main assembly "asm_TheoJansen_walker"?
When I try to check one leg, e.g. "walker_leg_1" by clicking "Edit Placement of a Part" the message in the Report view is: "Please select a linked part".
I.e. how are the legs linked to the main assembly?

In addition, when trying to "Insert a Part" to this assembly there are listed Parts named "varTmpDoc#Assembly..." - where have they been generated?
I guess it's combined to my first questions, but I can't see/understand how.

Many thanks in advance for further explanations!

[Zolko]

How have you actually done the main assembly "asm_TheoJansen_walker"?

you need the development branch of the Assembly4 workbench (v0.10.8): download the ZIP archive, extract it, and put it (or link-it) into the FreeCAD/Mod folder, where you must have removed the installed Assembly4 directory.

[ppemawm]

And of course the animation of it:

Marvelous model.

I especially appreciate the animation.
Assembly4 never ceases to amaze me of its straight forward capabilities.

[project4]

[Mind blowing icon]!

[M4x]

Awesome, I love it!

[user1234]

Really impressive! One question: how long took it to animate (not to built up the model to animate, i mean one cycle 360°).

Greetings
user1234

[Zolko]

how long took it to animate (not to built up the model to animate, i mean one cycle 360°)

about 10-15 minutes on a Core i5. The process seems multi-threaded and uses all available cores. I calculated in 5°steps