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theo jansen mechanism Answered

OK, I finally got hold of measurements for theo's strandbeest. these come directly from theo himself which means there accurate however it also means they're not in English. the numbers are there and they're easy to figure out, but it would be nice to know what the paragraph beside them says. so if any can read it, please post a translation. thanks

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gedion4000
gedion4000

8 years ago

this should be a better drawing of the leg. hope you can all read them better.

TheoJansenLinkage.jpg
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McMech
McMech

9 years ago

Sorry, I know this is an old post but I need to ask. If I were to use these dimensions for a science fair project (Comparing legged to wheeled robots) would I need Theo Jansen's permission?

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Kiteman
Kiteman

Reply 9 years ago

No - they've spread so far around the net, they are basically common knowledge. It would, however, be appropriate to credit him, maybe include a link to his work.

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McMech
McMech

Reply 9 years ago

Thanks, that's what I thought but I didn't want to risk it. I'll make sure to specifically call it a 'Theo Jansen Mechanism'

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MichelMoermans
MichelMoermans

10 years ago

The following is a direct translation from a 20 year old Belgian who speaks dutch as his mother language (it's me btw ;) ). I kept the translation so directly translated as possible while staying in the context of the text. Hope you enjoy any questions don't feel afraid to ask

Then he would have been busy with that for 100000 years. That much time was not available, therefore he took refuge in the evolutionmethod.

In the computer 1500 legs were created with poles of lengths that were random. The computer looked which legs where close to the perfect walking curve. From those 1500, one hunderd of the best lengths were slected. They got the honor to reproduce themselfs (translation note: evolution so he means "sex to reproduce". There poles where copied and combined to 1500 new legs. These 1500 legs showed a resemblence to there parents and where tested for their comparison to the perfect walking curve. This proces repeated itself for many generations and the computer stayed on for many weeks, months (day and night).
Finally 13 numbers came out, the ones who gave the ideal lengths for the nessecairy poles. The end result was the leg of the Animaris Currens Vulgaris. It was the first walking beachmonster (translation note: beachmonster is the english translation of strandbeest). Yet the Vulgaris resisted heavily against walking. A new computerevolution deliverd the legs of the generations that followed.
Here are the magic numbers: a= 38, b=41,5, c=39,3.... (I didn't want to copy these further)

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larslovespeace
larslovespeace

10 years ago

this diagram is on his strandbeest website.

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Groxx
Groxx

11 years ago

 Holy cow, a million thanks for the numbers!  I've never seen them online before, and I've got a project I want to do with these legs...

I was debating just evolving my own set of numbers, but Jansen's own are known to work, and already done for me :)  I'd never be able to figure this level of detail out of pictures of his beasts, and coming up with the algorithm to evolve them would've been a real pain (and would put me over my time limit for this project).

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mmm1
mmm1

11 years ago

Does anyone know the diameter of the circle around which the axel rotates, moving the leg? and are these numbers metric or foot/inches?

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Kiteman
Kiteman

Reply 11 years ago

the metric/imperial question doesn't matter - what's important is the ratio of the various numbers.

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budsiskos
budsiskos

Reply 11 years ago

i would assume they were in centimeters and the radius of the circle is 15

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benjamander
benjamander

11 years ago

there are two arrows in the diagram pointing at "vaste punten." Google translates this as "fixed points." I'm going to assume that segments l and a are perpendicular to eachother, making the distance between them sqrt(7.8*7.8+38*38) or approximately 38.8... but if anyone has any insight, I would love to know what you think.

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starwarsfan
starwarsfan

11 years ago

I can not read the numbers. can someone post them.

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Kiteman
Kiteman

Reply 11 years ago

If you click the small i in the corner of the image, you can look at, or download, a larger version.

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westfw
westfw

11 years ago

Hey, I sorta know someone Dutch! He kindly provided the following:

...which would take him 105 years. That amount of time was not available, so he switched to the evolution method.

In the computer 1500 legs were created using rods of random length. The computer evaluated which legs approximated the ideal walking curve. Of these 1500 the best 100 were selected. They gained the privilege of reproduction. Their rods were copied and combined into 1500 new legs. These 1500 legs have some liking to their parents and were tested using the ideal curve. This processes went on for many generations and the computer was working for weeks and months (day and night).

In the end 13 numbers evolved, indicating the ideal lengths for the rods. The final result was the leg of the Animares Currens Vulgaris. It was the first walking beach-animal. But still, from time to time the Vulgaris resisted walking. A new computer-evolution produced the legs of the subsequent generations. These are the magig figures: ...

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westfw
westfw

Reply 11 years ago

I would not have expected a computer to be involved. Interesting. I wonder if it's one of those things that could be done on a modern home computer in mere minutes...

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n8man
n8man

11 years ago

Do not click link, flagged. Can you please keep this site clean and stop posting the link.

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guyfrom7up
guyfrom7up

11 years ago

Whenever I found the picture (through hours of searching) I was soooo happy. I found it like a year ago. I started translating it, but I got lazy. I think it's in Dutch. All it is is explaining how the mechanism works, like a computer generated it so that the "foot" has a relative flat run along the bottom but it lifts it up after a gait. Don't worry about the paragraph.

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Kiteman
Kiteman

Reply 11 years ago

Dutch is a good guess - Jansen is Dutch, and his machines stroll around Dutch beaches. You're right, though - the diagram is the gold.