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Author Topic: Low cost Robot Hand (with only one motor)  (Read 3294 times)
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Hello,

Here there's a video of a robotic hand I build!  smiley

I know (at least in my experience) that the end effector can be a very complex part to make: because I'm very satisfied of this result I've obtained using only one motor, I'd like to share it with you, hoping to be useful to someone looking for ideas!



Let me know,
A.
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That's awesome, great job!!!!
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That's very good... thanks for sharing that.

I was going to do this but couldn't find nice thick straws and in anycase they're very flimsy. The garden hose is a great idea...
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Roy from ITCrowd: Have you tried turning it off an on again?
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the music sucks
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Your assertion that you need N motors for N movements is wrong.

A small three-wheeled robot with 2 independent motors  has 4 basis movements,
forwards,  spin right,  spin left,  or backwards.

It is also quite clear in your video,   that the forearm is being manipulated off-camera
by a human,   and not by any kind of robot arm mechanism.

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Your assertion that 90% of hand movements involve grasping objects or picking up objects
is also very dubious.

I type ( as in keyboard ),  10's of thousands of movements a day  and I pick up maybe a dozen objects a day.
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the music sucks
Well, I'm not sure this is a constructive feedback  smiley

Your assertion that 90% of hand movements involve grasping objects or picking up objects
is also very dubious.
It's known that the major part of the use of our hand is just grasping. You can grasp different objects in different ways but is one movement.
90% maybe is exaggerated, but I was trying to summarize in only one frame the whole preface.


Your assertion that you need N motors for N movements is wrong.
A small three-wheeled robot with 2 independent motors  has 4 basis movements,
forwards,  spin right,  spin left,  or backwards.

You're talking about another context. I don't have weels, because I tried to build a hand, not a car.
I just said taht moving N fingers independently requires N motors.

It is also quite clear in your video,   that the forearm is being manipulated off-camera
by a human,   and not by any kind of robot arm mechanism.
Well sorry but here I understand that you didn't realize what the purpose of the video was.
I just wanted to realize the end effector. All the tests, are tests on the functionality on the end effector.
I never said I created a robot capable of playing chess, did I?
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What size of garden hose did you use in the low-cost robot hand?
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What size of garden hose did you use in the low-cost robot hand?
The diameter of the hose is 1.5 cm.

The thickness is approximately 3mm for thumb, index, middle, and 2mm for ring and pinkie (if you see the video if can recognize two different kind of hoses). This is because a thicker hose is harder to pull, but is more effective to create the opposable thumb mechanism.

A.
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What size of garden hose did you use in the low-cost robot hand?

I was wondering that too... looks about 10-12 mm to me, 3/8"-1/2"?

Edit... ah, I see. The different wall thickness is good thinking!
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I just bought some of that hose... it's quite curled from being rolled up in the shop. I'm wondering how to straighten it? Or once I cut those notches at the knuckles maybe it won't matter....
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I just bought some of that hose... it's quite curled from being rolled up in the shop. I'm wondering how to straighten it? Or once I cut those notches at the knuckles maybe it won't matter....
I'm glad you liked the idea  smiley

Well, when I bought a long piece in the shop it was too quite curled, but when I cut the five fingers (in my case 12cm each, more or less) the shorter hose pieces were much more straight!

A.
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I'm also wondering how many bend / straighten cycles the tube can handle before it loses its springiness to loosen its grasp  smiley-cool

But right now that doesn't matter...
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Well, so far I can guarantee it at least for some hundreds of cycles  smiley-grin
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Nice project, I'll probably try to do something similar in the future smiley
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For some Awesome Arduino Projects  click -> www.randomnerdtutorials.com

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