Welcome to my instructable on animatronic hand building.
  • Addition to the section on the crank shaft build!
  • Addition to the section on the fingers
  • addition to the section on tumbling
I was going for a rough industrial look from a bygone era.  Solenoids and servo's are the easy way to go, and would not fit the part.  Neither would arduino processors or other digital controllers give me that analog feel i was after.  A tuned crankshaft complete with push/pull rods, air-craft cable and chunky steel makes for an old school feel and sound.  I'd call it steampunk-ish, but vintage pre-industrial post Russian is more apt.

Originally this was going to be a replica build of the hand and arm displayed in the terminator movies at Skynet.  But, then i wanted it to move.  I was still going for the look of a statue/display model, but at the same time I wanted it to be interactive.  A couple of years back I built a robotic salmon for the local museum complete with infrared camera eye, monitor display and articulating mouth fins and body.  All of these could be controlled by the patrons themselves.  Interactive art is the new black.

This build does take into account that the builder can weld and has access to a welder.  Of course this could all ways be built with using rivets or nut and bolt, but would be need to be thought out a bit more.  I'm sure one could use alternate metals too, I used aluminum rod for the fingers and thumb, and the balance out of recycled bits of steel.  Total cost for this was about 30$, with the biggest cost being the aluminum 17$.  These were scrap, but when buying metal such as this they charge by the pound regardless if it came from there scrap bin.  The rest was used up buying washers, odds and ends, air craft cable and the brass connectors.

This instructable has been a while in the making.  All though the total combined  hours wasn't that great, the space of 30 minute intervals stretched it out over a month.  Total time was about 16 man hours.

Last but not least, safety.  Working with metal will make you bleed, its gonna happen.  Be careful, its one thing to get small cuts from metal (which you will) its another to have a penetrating eye wound from flying disintegrating zip cut discs.  Where full face shield masks, ear protection and watch where your body is in relation to killer tools at all times!

Finally, if you do build this, be ready for the "Big bang theory jokes"  I would put an actual video of the episode below, but... the powers that be at youtube would frown on that.  So... just copy and past the following!


Have a look, and please remember to VOTE and take the time to rate me.  Thanks and enjoy!

Here is the hand running on a test motor, a 12 volt automotive motor.  This would be much too fast and loud for a permanent display, but still its awesome!

Here it is finished, much slower but I love the articulation.

Step 1: Supplies and tools

The following supply list will vary, depending on your availability of goods and or budget.  Be open minded as to what you choose to use.

I used:
  • 1" aluminum rod, about 1 foot
  • 3/4" aluminum rod, about 3 feet
  • 1 1/2" x 1/2" steel bar, about 4 feet
  • 1/8" steel plate, about 3-4 square feet
  • 2" heavy duty washers, 6
  • Thin air craft cable, about 4 feet
  • 1/4" steel rod, about 3 feet
  • 110v barbecue rotisserie motor
  • small 3.5v dc wall=wart power supply
  • Automotive LED detail light
  • 3/8 bolts, connecting nut, washers & acorn nut
  • Various small screws, cotter pins, small nails and wire tie down nails
  • Silicone tubing, black, about 3 feet
  • 110v rated switch
  • Shrink tubing or electrical tape
  • Patience, about 9 metric tons

Tools used:
  • 110v wirefeed welder
  • Dremel tool and various bits
  • Angle grinder with zip-cuts, grinder wheels and flap discs for aluminum and different ones for steel
  • Hammer
  • Chisel
  • Wire stripper
  • Rock tumbler, with grits, bb's and turtle wax
  • Drill and a variety of size drill bits
  • Tabletop clamp
  • Variety of small hand tools, clamps vise-grips etc...
  • lots of safety gear, glasses, flame resistant clothing, thick leather gloves, full face shield and ear protection.
  • A fire extinguisher isn't a bad idea as well.  Not that I needed it, but...
What I would have like to have used:
  • Band saw
  • Drill press - oh please Santa!
  • http://www.sears.com/shc/s/p_10153_12605_00922900000P
  • Bench grinder

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; <strong>As Borat would say, &quot;Very nice how much!&quot; </strong><br> <br> <br> Watched your video and feel consoled that I am not alone with messy workbench :). By the way, why robot (your gender) would need the bathroom eh?
messy workbench is my life... no matter how i try to keep it clean, lack of space. Robot boy might be better i guess
coolest thing ever<br>
hola soy de mexico realmente excelente un buen trabajo muchas felicidades ahora yo estoy trabajando en algo parecido me encantaria que me atudaras con imaenes de como lo fuiste realizando para darme grandes ideas por que eso son grandes ideas tuyas y bueno gracias por la ayuda
gracias feliz de ayudar a
Wow! what a great technological idea<br><a href="http://www.stroy2010.ru/brigada-stroitelej.html">brigada stroitelej</a>
Thank you!
Wow, that's really well done, just imagine the look on peoples faces if you could attach this to your shoulder and put your hand into your shirt :D!
Your design is just same like my design.but my design are more cheaper.<br>here's the link to my design<br>http://ideaprojektahunakhir.blogspot.com/2010/11/robot-arm.html
I'm working on something very similar to this, only made from cheap and easily found materials, with a goal of creating a working prosthetic for no more than $50. I can see the basic design of the fingers from the pictures, but I'm curious exactly how the joint pins are put in? I assume they have to be removable, yet permanent enough not to fall out. Your project looks great, and I also learned to avoid using guitar strings from reading your comments. One less failure for me to learn from! :) Good luck in the contest.
Simple to do, tricky to explain. Imagine having a block of aluminum, with a hole drilled right through it. Now insert a steel nail, screw or bolt of the same size as the hole through it. Now one end of the block will have the large head coming out of it, while the other will have the tip protruding about 1/4 of an inch. With a welding unit, ground to the aluminum block. next briefly touch the tip of the electrode to the tip of the protruding steel nail. It tip will turn molten and will flow out making a molten rivet head. The rest of the steel nail will be kept cool being in the block of aluminum. Steel and aluminum will not fuse together except with very specialized equipment. To remove it, you simply, carefully grind just the steel tip off. When I was doing the setup of the project I just used cotter pins to temporarily hold it all in place, then when I was ready I would weld it. Hope this helps, and good luck. With scrounged materials this could be built almost for free, the tricky part is the tools to do it with. Having a welder and an angle grinder are key if using steel and aluminum. If this is for a real prosthesis, you would want to do away with steel all together. Perhaps some of the new low heat mold-able plastics. For the fingers, why not try casting oogoo, over aluminum tube frame. The aluminum would serve as the cable housing and for attachment purposes. The oogoo would provide the needed bulk and provide a grippy skin like surface. Oogoo can be found on this site, hope this helps
Neat trick, but not useful for my application. Thanks for the explanation!
Awesome Job!!!
Very interesting. I wonder if some cheap guitar strings (or piano wires?) could be used for the control wires. As for a drill press, might try Harbor Freight. They have some incredible tool deals; I think I paid $50 for mine.
Of course, the strings would work but I would stay away from any coiled wires. Issue there being the stretch factor. Guitar strings often have to be re tightened as they stretch with use, all though it would be tiny and over a long period of time. Princess auto is the harbour freight of Canada, and I'm waiting for sales
Love it I gave it five stars. I'm making one<br>Greg
Thanks everyone!!!!!!!!!!!!!!!!!
great job i voted!
Wo,...........It looks like very cool.I Iook forward to more of your Creations<br>http://www.wholesaleeshop.com.au/laptop-battery/ibm-thinkpad-x60.htm<br>is good.
Very cool! I think you used every last bit of the 9 metric tons of patience...It also looks like it got the black cat seal of approval- always a good thing.<br><br>Here's my kitty- http://i168.photobucket.com/albums/u177/JKelty/MaxTheCat2.jpg
Ooooh , wow I can't wait to see how the rock tumbler did it's magic. This is truly cool. I Iook forward to more of your Creations. Yay.
Pictures will be uploaded shortly showing the various stages of the finger joints being tumbled in the rock tumbler

About This Instructable


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Bio: See some of my work here and as always accepting orders for custom design and fabrication as featured on Discovery Channel, Wired Magazine, Gizmodo, Engadget ... More »
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