Internalized Marionette style legs

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Re: Internalized Marionette style legs
« Reply #15 on: August 26, 2019, 09:52:42 pm »
Here's a small-scale prototype leg that I made some years ago.

I never got around to motorizing it; in the video, I'm pulling the tendons with my fingers.

One difference vs. what I think goaty wants is that the tendons aren't fully internal to the legs.  I put them out on those little spars for better mechanical advantage.


Hopefully Something

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Re: Internalized Marionette style legs
« Reply #16 on: August 27, 2019, 06:33:16 am »
 AGI is a very serious pursuit.   :)

Screenshot-1306" border="0

Tried and discarded a bunch of designs, mostly they ended up being really complicated and difficult to construct. Finally got something simple, only two parts, housing and legs, and the legs are just the same part repeated. Still need something to hold the joints together, and a distribution for the 8 strings required to control each leg. Maybe just tech-flex air muscles in place of strings? There is probably enough room for that.
« Last Edit: August 27, 2019, 08:18:30 am by Hopefully Something »



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Re: Internalized Marionette style legs
« Reply #17 on: August 27, 2019, 12:45:24 pm »
there needs to be an obstructor rod which is going to sit against a rotating plane to cause a rotation when it spins.
So it will have to hold the weight of the robot? Is it 3d like a ball and socket, or 2d like a hinge?  (just think of it like a bone - he needs bones there just like us. :)

The thing not in the explanation here is of course how to add the linear drives which pull on the tendons, and how to pass the power from the battery through the computer to set their positions.    You can use electric or pneumatic, and i'm such a dodgy bastard id say its better off without gears or spoolies, they just complicate matters.
The cheapest might be regular electric motors pulling string on a stick, like a puppeteer. Hehe I feel the same way about valves, I went out of my way to design a valveless steam engine one summer. It would need to be really big and heavy to work though.

Theres actually another roboter on the internet who made a beautiful pully wire worm, and he hates gears in em too :)  you can join the club if you want.
Yeah, that type of thing is really fragile. (gears, valves, bearings) Needs to be exactly right or it stops working. Not the type of thing that can wander around on an alien planet for a hundred years, (as things should).  :)
Something that has loose tolerances, which can take damage but keep working, that's how I envision the best machines.

Yeh that "obstructor rod" Is a ball hinge bearance on the end, if you want it to be.

That "lever" idea is cool - I didn't think of that, but wouldn't it take too much space up - because the lever would have to be inside, I would think a linear drive would take less space up.  but the lever will count as a change up transmition, depending on the length, the same as a cog does.

But Hopefully Something, if you've got a better idea, doing it your way is probably better for you, considering I actually haven't even built it yet to know what its really like,  it might actually be really bad, what ive come up with.     
The main thing I was trying to achieve was to get something that I could caste in one piece with resin or rubber,   so to make a virus all I would have to do is miniaturize the die.
I see you've got a program running?
Do you have a physics simulation for your robot? On that last picture?    Record a video of it for me would be cool,  id like to see your software!

Writer of Minds -  that leg is really cool!    Thanks for showing.   Yes I haven't even built mine yet, its still just an idea,  maybe it is weak I don't know.       I like the return springs,   im not doing that in my one,  im having two separate pulling locations back and forth.
Because im not using a spring, I dont have to worry about getting the spring strength "just right", also it doesn't fight against itself -  I just pull either way and its equal power.

« Last Edit: August 27, 2019, 04:26:43 pm by goaty »


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