Instructables
Picture of The Claw.
Claw 7.jpg
This is how to build... The Claw.


The Claw is my awesome 3 fingered robotic gripper. it is controlled with a servo, and can be attached to another servo which acts as a "wrist".

To see what it should look like, there is a video here http://www.youtube.com/watch?v=-R7vCUfmeNU.

(for the NRW contest, I am 15)
 
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Step 1: Laser cut the pieces

Picture of Laser cut the pieces
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Below are the DXF designs to laser cut the pieces. It should be fairly self explanatory. If you don't have access to a laser cutter, then the designs are also below.

You will also need:
3 x 3mm bolt
3 x 3mm nylock
some multicore wire
some 3mm dowel
3 small pull springs
glue
a drill
a servo
4 x 4mm bolt
4 x 4mm nut

Step 2: Assemble the base

Picture of Assemble the base
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You should have 3 circular baseplates. one of them has two long rectangular slots in, put this to one side. Glue the other two plates together, making sure all the holes line up. I used bolts to make sure the holes were lined up. 

Step 3: Add the jaw mounts

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Glue the 6 smallest pieces into the baseplate, ensuring they are perfectly upright.

Step 4: Mount the servo mounts

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Bolt the servo into one of the two servo mounts using the 4mm bolts and nuts. Then, turn the baseplates over and glue the two mounts in.

Step 5: Add the dowels

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Cut 6 pieces of 3mm dowel to 50mm long. Insert them through the 6 outer holes on the two baseplates, so the ends are flush with the side opposite the servo. I found that scraping the ends with a pencil sharpener blade ensured a good fit. 

Step 6: Add the 3rd baseplate

Picture of Add the 3rd baseplate
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Hook the 3 springs over alternate dowels, making sure they are on the ones that sit between pairs of jaw mounts. Then, push the 3rd baseplate onto the dowels.

Step 7: Glue in the "wrist" mounts

Picture of Glue in the
Glue the two "wrist" pieces into the 3rd baseplate.

(Sorry about the lack of picture, I appear to have forgotten to take one.)
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ka3ros3 months ago

I really like the design.

I'll reproduce a tiny one but with a stepper motor and a screw instead of the cables.

rpjamess13 years ago
I made a claw using three one time but they were set with a two-one configuration, not circular like this. I used rubber bands instead of springs but have another thought. What about two wheels connected to the servo, feeding wire as in your plan, closing the claw, and the other feeding the opposite way to where the springs are attached? This would make the open and close completely dependent on the servo and no need for the springs.
AntMan232 (author)  rpjamess13 years ago
I thought about rubber bands, but decded springs were probably better. Also, I came up with your idea about wires pulling both ways myself, but it was simpler to build using springs. Thanks for the feedback though!!
The springs are a much better idea. After about three days of playing with the design we had to replace the bands because the snapped. Let me tell you about the pain my hand went through while fine tuning everything...
hlugo3 years ago
i saw your claws and arm with wrist on youtube and i just have to say they are great. im just wondering if you have this in a CAD file that i could use?? im trying to make the claw cuz it looks awesome.
AntMan232 (author)  hlugo3 years ago
I can't release the files for the wrist and arm, because they are part of my IGCSE project, and the exam board might get funny. The file for the Claw above, though, is attached.
tinker2343 years ago
hey could i use a dremel
AntMan232 (author)  tinker2343 years ago
So could I...
so i can just use my dremel
This is most certainly the best set of instructions for a 3-pronged claw that I've found after quite a bit of searching.
I'm looking to do one with a slightly different design, though, similar to this one:

http://www.clawmachinesdirect.com/claw.jpg

Of course, I know next to nothing about laser cutting, and can't edit the dxf file myself...
If anybody could help, that would be great!

Also, what is the scale of this?
AntMan232 (author)  Whitestar2453 years ago
The whole assembly is about 20cm long. If there is a better filetype for you, just ask and I will send it to you. If you want to edit DXFs, then i can recommend QCAD or Draftsight. Please send me a photo if you make one.
Very nice, this could be quite useful in some evil world domination robot! You should post the drawings to thingverse too...
its a dalek claw isn't it?
I thought the Dalek's had a toilet plunger, not a claw...
But still, it is an excellent addition.
They only had a toilet plunger because the BBC couldn't afford grippers..
AntMan232 (author)  JavaNut133 years ago
You wouldn't say that to a Dalek's face...
Not if I get all Bad Wolf up in its, uh, eyestalk thing.
some daleks have plungers others have claws, flamethrowers, extra weaponry and assorted other tools depending on their assignment.
AntMan232 (author)  The Ideanator3 years ago
That is the eventual plan! I will be using this as part of my GCSE project for tech, the project is technically a teaching aid, but ...
caarntedd3 years ago
The Craw!
Not Craw, Craw!
AntMan232 (author)  gannon12raiders3 years ago
???
It's a reference to "Get Smart", the american spoofy spy TV show from the 60's. Agent 99 (Maxwell Smart) had an Asian supervilan enemy called "The Claw", but due to an unfortunate and racist play on his accent it always came out "CRAW!".
AntMan232 (author)  shadeydave3 years ago
Sorry, I'm about 40 years younger than i would have to be to have seen that!
No! Not the Craw, the CRAW!!
ckpirate3 years ago
Great instructable! By the way Maxwell Smart was Agent 86, Barbera Feldon was Agent 99.
Dumchicken3 years ago
is this like the claw shot from legend of zelda: twilight princess?
AntMan232 (author)  Dumchicken3 years ago
No.
Hilarious! Great response!
dombeef3 years ago
This is just like the claw I made and instructable for, though your's is motorized, good job!
dombeef dombeef3 years ago
It is also exactly one month after the one i made's date when I posted it on instructables
AntMan232 (author)  dombeef3 years ago
To be perfectly honest, I have never seen that before today, and there really isn't much resemblance. I designed mine on my own at home here in QCAD.
Tomcat943 years ago
No one can escape THE CLAWWW!!!!

Great instructable. I just wish I had the materials to make it....
twolf13 years ago
perfect for a big duo cosplay x)
Awsome job. For anyone who wants to get something laser cut go to Ponoko.com Cheap, lots of materials, and about 10 days shipped. I like the bamboo plywood.
baneat3 years ago
The Claw is our Master! He decides who will go and who shall stay!
aashilrv baneat3 years ago
LOL I love toystory........!!!!!!!!!
AntMan232 (author)  baneat3 years ago
You have the right idea!
Kiteman3 years ago
Is this your own design, or one you've gotten from somewhere else?
AntMan232 (author)  Kiteman3 years ago
I designed this all myself. This is the 3rd version, if you follow the youtube link and look at my other videos, you will see the 2nd version. I have been revising and developing this for a while!!
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