Human Robotic Hand

[DeeSnyder1978]

SKYNET AND T-101 APROVES THIS HAND.

[p5qlse]

Skynet would have approved.

[jaked305]

: The Skynet Funding Bill is passed. The system goes on-line August 4th, 1997. Human decisions are removed from strategic defense

[NewAgeDirector]

Great video keep up the good work.

[bradsommers1961]

I could never figure out how this type of finger worked until I read your comment on four bar linkages. What an eye-opener! But then I could see the next big hurtle: figuring out the ratios. The only way I know of would be trial and error (and one could use cardboard or legos for trying them out). What software did you use? Yours is my favorite design so far (Shadow hand aside). I'm about to buy a Sherline lathe/mill combo (non-CNC, I don't have the patience to learn both simultaneously). Tx

[misteRoboto1]

Thanks much! All your intuition is right on - almost any 3D CAD can get this job done. The math can be done, but complex shapes are extremely difficult to account for on paper. Careful on your machining investment - nothing against Sherline. But if you are going to non-cnc I would suggest looking for a used bridgeport knee-mill and a lathe. You might find yourself wanting to cut 7075 aluminum soon at a reasonable speed, etc. I tend to shop and save to get bigger tooling / lasts longer. cheers

[bradsommers1961]

@misteRoboto1 Well, there's alot to be said for buying a larger lathe/mill, especially in view of the fact that I would like to machine parts for small scale live steam. I'm lucky to have a friend who is a math whiz (masters degree in electrical engineering and worked for Microsoft - the kind of person who likes to write machine code and assembly language programs for fun) who will do any math that's beyond me. I have also looked at used South Bend machines.

[misteRoboto1]

I love South Bend lathes. Watch for spare parts availability (on anything really). One thing I would highly recommend is getting a spindle bore around 1.4375". For small parts a collet head will save you a LOT of time and increase your acc. Smaller collets are about 3X what a collet would be for a spindle of the above size. If you search for 3D CAD I think you'll be surprised at how cheap what you need may be.Of course, end of quarter negotiations w software sales is best ;) cheers -

[foxawax1]

Hi there,

I am passionate about electronics and animatronics but still at an early stage.

I would like create a robotic hand like yours for my final project in technical art and special effect in London.

Could you please tell me if a tutorial would be available (online or book) for such a complex hand as yours or similar.

In the meantime, well done, you did a great job!

All the best

Pierre.

[misteRoboto1]

Hi Pierre,

Thanks much. When you boil this hand down each finger is 3 four-bar linkages (wiki that in four-bar linkage mechanism). There are a lot of ways to do this. The trick is to make the motion smooth and not clash the parts together. I was able to get all the curves into these parts because I used a simulation software to check it before our 3-axis CNC mill makes the parts. The old-school way of doing this mechanism that a bunch of 25-year effects veterans in LA is cardboard and pushpins

[10GreenDay01]

terminator

[BobvanDijk]

@10GreenDay01  it's ARNOLDS!

[misteRoboto1]

Thanks much!The only source I can recommend is "Mechanical Engineering Design" by Shigley. Four-bar linked mechanisms is what to look for. We use 3D kinematic simulation here. Be careful - CNC tolerances have to be very tight or the mechanism will lock up...only being driven by Futaba S134 microservos at 4.5 volts does not lend much power to waste on bad kinematic design. Cheers - happy holidays!

[bradsommers]

Beautiful design and very smooth movement. Is there a book, website, etc. that you could direct me to that would show design for something similar? Thanks.