I thought that these hand projects might be useful resources:
http://www.openhandproject.org/
The number of fingers could be reduced to 2 or 3 plus thumb.
(BTW cartoon characters always have 3 fingers so this would be cute.)
The Flexi-Hand “might” work with just a single motor in the forearm since it is self opening.
It would be very useful longer term for Poppy to be able to manipulate and carry.
I would very much like to see the community’s thoughts on hands as a development area.
PW.
Also this is interesting:
Clearly with Poppy there is some serious down-scaling and simplification required to adapt any of these hand projects but simply having Poppy be able to grasp, say, a handle of a bucket or basket and carry it or perhaps push a button would be a huge advance.
I was right about a single motor being possible:
Yup, InMoov seems to be the best one.
You can see the InMoov project here: inmoov.fr
The objective is to construct a life size 3d printable humanoid robot.
Hi Folks,
Joel Gibbard here from the Open Hand Project.
I’m working on a miniature humanoid robotic hand for robots like Poppy.
It will be flexible and robust and I’m aiming to release it in around a month. There will probably be a 1DOF version that moves all fingers at once and a 5DOF version with individual finger movement. I would love some feedback to help make this exactly what you would want! There’s a short survey here. You can keep up to date on developments on twitter through @openbionics!
for very small scale hand like the one for poppy you should consider nitinol wire.
5 very simple spring and 5 short wires in the palm of the hand would allow you to move every finger alone. for sure, nitinol will not allow to be strong enough to grab objects, but it could be a start.
check this for nitinol.
http://www.dynalloy.com/pdfs/TCF1140.pdf
and price is close to zero.
this one is a bit thick
http://www.ebay.com/itm/Body-Temp-0-01-0-25mm-Nitinol-SHAPE-MEMORY-Wire-magic-tricks-robotics-5-feet-/261108814282?pt=LH_DefaultDomain_0&hash=item3ccb4c51ca
but this one is just perfect
https://www.makertronics.co.uk/muscle-wire-0.005-diameter-1-foot-long.html
you can put the wire in a soft silicone tube to protect from overheating.
they have very thin tubes here
you can find some clues about the electronics here.
http://www.musclewires.com/Images/Customer%20Instructions%20for%20Moving%20Hands%20Kit%20F1726Rev%20C.9.pdf
http://fab.cba.mit.edu/classes/MIT/863.10/people/jie.qi/flexinol_intro.html
Other useful resources for anthropomorphic hand design:
Humanoids 2014 Half-Day Workshop on “Anthropomorphic Robotic Hands: Design and Control” held in Madrid, Spain, November 18-20th 2014:
http://www-lar.deis.unibo.it/people/gpalli/Humanoid_Workshop/index.html