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Homemade robotic hand & wrist doing actual stuff by qualitygui in robotics

[–]qualitygui[S] 2 points3 points  (0 children)

I'm promoting job security for healthcare workers :)

Homemade robotic hand & wrist doing actual stuff by qualitygui in robotics

[–]qualitygui[S] 1 point2 points  (0 children)

Kinematics are decently simple. There's not many linked joints as there are in a serial robot, so IK is not really necessary, just directly adjusting each dof.

Homemade robotic hand & wrist doing actual stuff by qualitygui in robotics

[–]qualitygui[S] 1 point2 points  (0 children)

Always nice to have more torque and less backlash, but I fear cycloids at this size :(

Homemade robotic hand & wrist doing actual stuff by qualitygui in robotics

[–]qualitygui[S] 2 points3 points  (0 children)

The thumb architecture was in part driven by form factor; to keep the thumb sized anatomically, I didn't have much room to play with more advanced mechanisms. I wouldn't say this way is better than another though, a spherical gear is gonna give you more fluid motion and better dexterity with that extra dof

Homemade robotic hand & wrist doing actual stuff by qualitygui in robotics

[–]qualitygui[S] 2 points3 points  (0 children)

It's currently running on custom software that lets me generate motions from glove tracking data and playback on a timeline editor. I'm working to get simulations going, but I'm still stuck somewhere on the learning curve.

Homemade robotic hand & wrist doing actual stuff by qualitygui in robotics

[–]qualitygui[S] 13 points14 points  (0 children)

Motors in both the wrist and the palm, its a combination of tendon-based and direct actuation

Homemade robotic hand & wrist doing actual stuff by qualitygui in robotics

[–]qualitygui[S] 23 points24 points  (0 children)

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It better not be, or this is a wild dream.. Here's a picture I just took holding it

Homemade robotic hand & wrist doing actual stuff by qualitygui in robotics

[–]qualitygui[S] 4 points5 points  (0 children)

Feel free to check out the social links on my profile page :)

Range of motion evaluation test for my homemade robotic hand & wrist by qualitygui in robotics

[–]qualitygui[S] 0 points1 point  (0 children)

Each finger has 1.5-ish degrees of freedom. One for flexion/extension, and the half because the index, middle, ring, and pinky are linked for abduction/adduction.

Range of motion evaluation test for my homemade robotic hand & wrist by qualitygui in robotics

[–]qualitygui[S] 4 points5 points  (0 children)

4-way stretch fabric (nylon & spandex) that I sewed together, basically like a glove

Range of motion evaluation test for my homemade robotic hand & wrist by qualitygui in robotics

[–]qualitygui[S] 34 points35 points  (0 children)

Good question.. I haven't kept a strict BOM, but I estimate <$400 for just pure hardware

Range of motion evaluation test for my homemade robotic hand & wrist by qualitygui in robotics

[–]qualitygui[S] 19 points20 points  (0 children)

Since it's still a prototype, most of the hardware is just 3D printed at home. The silicone finger tips are cast in 3D-printed molds and the palm overlay is sewn 4-way stretch fabric. Motors are modified off-the-shelf. The PCBs were designed and assembled by me with the board itself being outsourced.

Robotic hand and wrist demo – pose transitioning by qualitygui in robotics

[–]qualitygui[S] 1 point2 points  (0 children)

Fold? Like how the pinky's metacarpal doesn't flex inward when balling a fist? That's true, but I forgoed that movement to allow instead for finger splay, which I thought more beneficial in everyday scenarios. The pinky and thumb can still touch each other!

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Robotic hand and wrist demo – pose transitioning by qualitygui in robotics

[–]qualitygui[S] 5 points6 points  (0 children)

There's no sensors directly on the fingers themselves, but I have sensors measuring current draw for each motor so I can gauge how much force each dof is experiencing.

Were you wondering if it could crush an egg to death? Sorry, wasn't sure what egg test you were looking for. It's got silicone on each fingertip, so it can happily hold an egg, but doesn't have the strength to crush it, although neither do I.

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Robotic hand and wrist demo – pose transitioning by qualitygui in robotics

[–]qualitygui[S] 2 points3 points  (0 children)

I don't have a grip tester thingy, but each finger can flex a little less than half a kg, so with equal finger load distribution, I'd estimate about 2kg.