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Step 1: Design
Attached are pictures of the design using 'google sketchup'.
I found this design of the finger on the net which allows a single servo to provide full motion of curl of a human finger.The design works best when Aluminium is used for the cut outs of the fingers, but as I had perspex available I went with the weaker option which resulted in brittle fingers.
All the fingers are the same design but a variation of measurements, except for the thumb. they can be found below:
The designs below are the ones I sent through to a laser cutter here in Johannesburg for about R350 for all cuts and material.
they required the files to be sent in 2d DXF format, so if you alter the design in sketchup, make sure you export it in the correct format.
The rest of the cut outs are made up of wrist and palm sections.
index finger, middle finger, ring finger is roughly the same size.
pinky is slightly smaller than other fingers.
Thumb has different dimentions
I found this design of the finger on the net which allows a single servo to provide full motion of curl of a human finger.The design works best when Aluminium is used for the cut outs of the fingers, but as I had perspex available I went with the weaker option which resulted in brittle fingers.
All the fingers are the same design but a variation of measurements, except for the thumb. they can be found below:
The designs below are the ones I sent through to a laser cutter here in Johannesburg for about R350 for all cuts and material.
they required the files to be sent in 2d DXF format, so if you alter the design in sketchup, make sure you export it in the correct format.
The rest of the cut outs are made up of wrist and palm sections.
index finger, middle finger, ring finger is roughly the same size.
pinky is slightly smaller than other fingers.
Thumb has different dimentions
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please send me the microcontroller's code plus the circuit diagram if you drew it out
massive thanks
Ive seen people remove the controls and interface with this one quite easily, and its relatively cheap:
http://www.thinkgeek.com/product/b696/
http://www.robotshop.com/gws-servo-en.html
go back a page and look at the other servos, as I said, theres no need for 20kg-torque , anything above 10kg is more than enough, for the fingers micro servos of 1.6kg is even ok.
This is where I got 20kg ones from for another project:
http://robotics.org.za/index.php?route=product/product&path=64_214&product_id=138
they are not the best quality or accuracy.
1.) BreadBoard
2.) 20kg-cm torque Servos for wrist movement
3.) 2kg-cm torque Servos for fingers
4.) 40kg-cm torque servo for elbow and shoulder x1 or x3
5.) Force/Touch sensors
6.) Bend sensors/Resistors
7.) connector pins
Thanks in Advanced
Crushing force would depend on torque/ strength of the servos in the fingers as well as the material of the structure in which the hand is built . The small servos I purchased are cheap and the gears are made of plastic. The fingers themselves are cut from perspex which is quite brittle. Therefore the hand itself could not crush much more then a piece of cardboard, but if the hand were to be made out of aluminium; the servos to be high torque with metal gears, I rate the crushing power can easily crush a can.
Im not sure exactly what force crushes a can, but remember, in the hand you have 5 servos, so if a high torque servo is used for each finger such as 20kg-nm, that would be 5x the torque.(neglecting the length of the fingers)
hope this helps.
thank you .
also if you could share some detail for the legs.
thank you once again.
I got the bend sensors from robotshop.com. They wernt cheap, like $10 each , so if you worried about messing them you can try and make your own. Theres an instructable on it, basicaly its just a voltage divider.
If you are interested in the legs, go to my profile and look at the instructable on them, its called "Arduino Biped".
Enjoy