Hardware Store Robot Hand

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Here’s a robot hand which can be built using mostly hardware store items. It doesn’t have the strongest of grips, but it does have lifelike movement. The demonstration video shows it picking up small objects like a metal nut.

The image above shows the ring and pinky fingers of the hand beginning to flex. These are controlled by the servo motors mounted in the palm area. The skeletal structure of each digit begins with the links of a bicycle chain. The links are first separated by removing the friction fit rods. Each rod is replaced with a screw and a nut, which also allows the springs (which open the digits) to be anchored at each ‘knuckle’.

[Aaron Thomen] didn’t stop the design process once the hand was finished. He went on to build a controller which lets you pull some rings with your fingers to affect movement. This movement is measured by a set of potentiometers and translated into electrical signals to position the hand’s servo motors. The demo, as well as two how-to videos are embedded below.

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Crown Earns You The Title King Of The Junkyard

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[Greg Shikhman] wanted to use the school tools one more time before graduation. After hitting up some local motorcycle shops around town for parts he fashioned this crown for himself.

He didn’t pay ‘the iron price‘ as the motorcycle roller chain is waste material anyway. Chains do wear out and these were left over after being replaced with new ones. He first cleaned them up with a bit of WD-40 solvent, xylene, and soapy water to cut through the grime. There was also a layer of black oxide which normally keeps them from rusting which he peeled off with a dunk in some hydrochloric acid.

Chains are flexible and this would have made for a disheveled looking crown. The fix involved using an aluminum form the size of his head to keep the crown in round while he did his TIG welding. A double row of polished steel ball bearings take the place of jewels. As if the ten-pounder wasn’t painful enough he added four rings of bicycle chain as accents which he admits makes the thing unwearable because they dig into his noggin. We still don’t think that’s a good enough excuse to post about the project and not include an image of him wearing the thing during the junkyard coronation.

It would be fun to see a follow-up king-ring with similar LED features as that engagement ring but using this heavy-metal design style.

Wooden Machine Belongs In Willy Wonka’s Factory

Behold the wooden machine (translated) that is used for… well it does… it was built because… Okay, this is a case where asking what it does or why it was built is the wrong question. [Erich Schatt] began building the piece that he calls “Wheels” back in 1995. It took just seven years to complete, and is made entirely of wood. The video after the break shows a multitude of moving parts.

The chains were modeled after bicycle chains, which are used to transfer motion from the “rider” throughout the machine. The gearing for each segment was meticulously calculated, then perfected through trial and error. The complexity even calls for a differential and universal joints. It’s mesmerizing to watch and for that reason it’s made appearances at conventions and been featured in art exhibitions.

It’s also worth mentioning that this comes from a very humble-looking shop. [Erich] posted some pictures of his studio and aside from the abundance of bar clamps, it’s just your average garage or basement setup.

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Tanks Treads For Your Next Robot

If you ever wanted to incorporate tank treads into one of your build you should check out this guide. The method shown above is our favorite, which uses rubber fuel line hose and #10 machine bolts to hold together two lengths of hollow-pin roller chain. You can see the drive sprocket is keyed into the outer length of chain but the wheels that distribute the vehicle’s weight rest on the rubber tubing. You’ll also find details on building hinged track, molded track, plastic conveyor track, treadmill track, and bicycle chain construction. This should cut down on development time when you finally get around to making that paintball tank.

[Thanks BoKu]