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Topic: Low cost Robot Hand (with only one motor) (Read 3 times) previous topic - next topic

michinyon

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It's known that the major part of the use of our hand is just grasping.


Known by who ?   You just claiming it, does not make it true.

As I said,  I type thousands of characters a day,   and I pick up maybe a dozen things.

I quite like your hand,  it's good !    It is just the dodgy claims in your captions that I don't like.

michinyon

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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?


No,  but you did claim that your hand uses only one motor/servo.   To have a usable hand for picking anything up,
you would need some kind of arm  which will require more than one motor or servo.

ndrplz


Quote
It's known that the major part of the use of our hand is just grasping.


Known by who ?   You just claiming it, does not make it true.
As I said,  I type thousands of characters a day,   and I pick up maybe a dozen things.
I quite like your hand,  it's good !    It is just the dodgy claims in your captions that I don't like.


My source is a TED Lecture i saw about the "Intelligence of hand", by Antonio Bicchi, who is a Professor of Robotics at University of Pisa. You can find it here:
http://www.youtube.com/watch?v=JZnbgJbqWb0

but unfortunately I found it only in Italian. He explains that our human hand is incredibly complex, and has more than 20 degrees of freedom. Nevertheless, we can have a quite useful robot hand with only ONE degree of freedom, and in his lecture he explains the possible important implications of this discovery.
Above all, he says this can be useful to make simple but light and cheap prosthetic hand.

My youtube video is not a TED talk, and I'm not a professor of Robotics and I've not 20 minutes to explain my ideas. I just tried to summarize all the important facts in just one frame, and English is not even my mother language. If you find my effort a "dodgy claim", I don't know what to say :smiley-roll:


you did claim that your hand uses only one motor/servo.   To have a usable hand for picking anything up,
you would need some kind of arm  which will require more than one motor or servo.


Sorry but I think you confuse the end effector with the rest of the robot (whatever it is). The end effector I realized is complete, and requires only one motor to do his job (grasp something). You can just google "end effector"...
Then, if you want to realize a whole humanoid robot, probably you will need other 40 motors, but this is another issue.  :)
Youtube channel: http://www.youtube.com/user/plzndr

zoomkat

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No,  but you did claim that your hand uses only one motor/servo.   To have a usable hand for picking anything up,
you would need some kind of arm  which will require more than one motor or servo.


Spin control! I don't think any claims to arms were made. The discussion title is "Low cost Robot Hand (with only one motor)". No claims to hands that require "arms".
Consider the daffodil. And while you're doing that, I'll be over here, looking through your stuff.   8)

JimboZA

Attached is a pic of my proof-of-concept finger based on ndrplz's video.

I was surprised at how much force it takes to curl the finger: servo sounded like it was straining and was drawing about half an amp.

But all good fun, and I thought, what the heck, might as well mount in in a surplus box to hold the servo steady while it hauled on the string. And lucky I had those two old electric conduit clamps in the cellar.

Note to self: get new blade in junior hacksaw, that fibrous hose is a bugger to cut otherwise.
No PMs for help please. Not active on this forum any more.

benjamin_m_obrien

Hi ndrplz

I was wondering if you could have a look at my post 3 Fingered Domestic Robotic Gripper (Uni Final year project) microcontroller in project guidance as you seem to have a good knowledge of robotics.

Thanks

ndrplz


Attached is a pic of my proof-of-concept finger based on ndrplz's video.

I was surprised at how much force it takes to curl the finger: servo sounded like it was straining and was drawing about half an amp.


I'm very happy you took the idea :)

To curl all the five fingers, I used this servo:
http://www.servocity.com/html/hs-645mg_ultra_torque.html

It's quite a good and powerful RC servo! (I never tested how much current does it draw, actually)

The idea of the electric clamps is good...
Also, can I ask you what kind of material the base is? Looks like a stone, but I think must be some kind of wood...  :smiley-roll:
Youtube channel: http://www.youtube.com/user/plzndr

ndrplz


I was wondering if you could have a look at my post 3 Fingered Domestic Robotic Gripper (Uni Final year project) microcontroller in project guidance as you seem to have a good knowledge of robotics.

Hi, my knowledge of robotics is smaller than you probably think  :)
Anyway I'll gladly take a look to your post as soon as i have some time!
Youtube channel: http://www.youtube.com/user/plzndr

JimboZA

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Looks like a stone, but I think must be some kind of wood...


Yep it's an upside-down-box. It's some kind of composite wood.... a bit like balsa but harder, I think it might be called superwood or something? It's a bit like really hard cardboard actually, about 4-5mm thick. It can by cut with a Stanley knife as long as the blade's good. Box is about A5 size and 25-30mm deep.

That HS-645 servo is about twice as torquey as mine: 7.7-9.6 kg cm vs 3.8-4.3 on my HK15138. According to that link, the HS-645 draws 1/3 to 1/2 an amp even under no-load.
No PMs for help please. Not active on this forum any more.

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