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rhysfawr4 (November 30, 1999 at 12:00 am)
For the record (in case anyone feels I was saying otherwise): zzytrewq is absolutely correct on Mr.J's original dimensions. And mb there is a difference in actual operation of the 'ouvre' if you follow it precisely and raise the crank axle to the specified height, I don't know. But after the amount of time I spent constructing the first one, there is no way my wife will allow me revisit building another one to find out! zzytreq: when you have finished making yours we can race 'em to see! Peace.
rhysfawr4 (November 30, 1999 at 12:00 am)
Hey, I checked out that vid you mentioned and it definitely appears that creation has the crank axle located higher than that of the 'hips'. However, that being said, my RC model walks pretty damn smoothly, and I have the crank axle on exactly the same plane as the 'hips' (See vid "Pastbot"). It could be that the specifics of each components' measurements on TJ's design have an envelope of flexibility, and while they are certainly all inter-related,contd...
rhysfawr4 (November 30, 1999 at 12:00 am)
contd..., as long as you alter them all in unison you will end up with a smooth motion. Also noteworthy on TJ's design: due to the length of the 'legs' I found my model became quite 'top-heavy' with motor/electronic components at crank axle level (my Vid will show you how I overcame that), and IMHO increasing the crank axle height on a motorized version will compound the balancing issues associated with a raised center of gravity. IE, when it stops/starts it will be prone to falling over.
qcampbell123 (November 30, 1999 at 12:00 am)
oh i see
zzytrewq (November 30, 1999 at 12:00 am)
You can motorize it or power it by a wind driven mechanism.
zzytrewq (November 30, 1999 at 12:00 am)
If you watch his videos you'll see the crank is higher than the hips. Look at this video 'Theo Jansen Beach Beasts' at 1:32 you'll see it clearly. I have see a few flash animations and you can see that having the crank on the same level as the hips causes a slight up and down movement with each step.I just found a copy of his original design notes with all the dimensions if you are interested. Cheers
zzytrewq (November 30, 1999 at 12:00 am)
rhysfawr4, I googled more info on his design and found a paper describing all the dimensions he uses. The crank is set 7.8 units higher than the main leg pivots. He may have changed it, but I doubt it.Contact me and I'll send you a copy. I'm going to make a model of his mechanism when I get the time.Cheers
rhysfawr4 (November 30, 1999 at 12:00 am)
zzytrewq, you can adjust the radius of the crank. Your '7.8 units higher' wants some clarification...I made a working remote-controlled model, and the crank's axle lies on exactly the same plane as the 'hips'. It walks fine. Evidence:"Pastbot"
qcampbell123 (November 30, 1999 at 12:00 am)
wut powers it?
zzytrewq (November 30, 1999 at 12:00 am)
The crank should be set higher than the "hips" of the legs. This is a common error in copied designs. Have a look at videos of Theo's and you'll see the crank is not on the same plane as the hips. The actual dimension is 7.8 units higher. |
