Giant Robot Arm Uses Fluid Power, Not Electronics

October 3, 2018 by Dan Maloney 7 Comments

Fair warning that [Freerk Wieringa]’s videos documenting his giant non-electric robot build are long. We’ve only watched the first two episodes and the latest installment so far, all of which are posted after the break. Consider it an investment to watch a metalworking artist undertake an incredible build.

The first video starts with the construction of the upper arm of the robot. Everything is fabricated using simple tools; the most sophisticated tools are a lathe and a TIG welder. As the arm build proceeds we see that there are no electronic controls to be found. Control is through hydraulic cylinders in a master-slave setup; the slave opens a pneumatic valve attached to the elbow of the arm, which moves the lower arm until the valve closes and brings the forelimb to a smooth stop. It’s a very clever way of providing feedback without the usual sensors and microcontrollers. And the hand that goes at the end of the arm is something else, too, with four fingers made from complex linkages, all separately actuated by cylinders of their own. The whole arm looks to be part of a large robot, probably about 3 or 4 meters tall. At least we hope so, and we hope we get to see it by the end of the series.

True, we’ve seen terrifyingly large robots before, but to see one using fluid power for everything is a treat.

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Maker Faire NY: Programmable Air

September 22, 2018 by Brian Benchoff 10 Comments

At this year’s World Maker Faire in New York City we’re astonished and proud to run into some of the best projects that are currently in the running for the Hackaday Prize. One of these is Programmable Air, from [Amitabh], and it’s the solution to pneumatics and pressure sensing in Maker and IoT devices.

The idea behind Programmable Air is to create the cheapest, most hacker-friendly system for dealing with inflatable and vacuum-based robotics. Yes, pneumatic robotics might sound weird, but there’s plenty of projects that could make use of a system like this. The Glaucus is one of the greatest soft robotic projects we’ve ever seen, and it turns a bit of silicone into a quadruped robot with no moving parts. The only control you have over this robot is inflating one side or the other while watching this silicone slug slowly crawl forward. This same sort of system can be expanded to a silicone robot tentacle, too.

On display at the Programmable Air booth were three examples of how this device could be used. The first was a simple pressure sensor — a weird silicone pig with some tubing coming out of the nostrils was connected to the Programmable Air module. Squeeze the pig, and some RGB LEDs light up. The second demo was a balloon inflating and deflating automatically. The third demo was a ‘jamming gripper’, basically a balloon filled with rice or coffee grounds, connected to a pump. If you take this balloon, jam it onto an odd-shaped object and suck the air out, it becomes a gripper for a robotic arm. All of these are possible with Programmable Air.

Right now, [Amitabh] has just finalized the design and is getting ready to move into mass production. You can get some updates for this really novel air-powered robotics platform over on the main website, or check out the project over on Hackaday.io.

Shop-Made Pneumatic Cylinders From PVC And Plywood

September 11, 2018 by Dan Maloney 26 Comments

You see a lot of pneumatic actuators in industrial automation, and for good reason. They’re simple, powerful, reliable, and above all, cheap. Online sources and fluid-power suppliers carry a bewildering range of actuators, so why would anyone bother to make their own pneumatic cylinders? Because while the commercial stuff is cheap, it’s not PVC and plywood cheap.

Granted, that’s not the only reason [Izzy Swan] gives for his DIY single-acting cylinder. For him it’s more about having the flexibility to make exactly what he needs in terms of size and shape. And given how ridiculously easy these cylinders are, you can make a ton of them for pennies. The cylinder itself is common Schedule 40 PVC pipe with plywood endcaps, all held together with threaded rod. [Izzy] cut the endcaps with a CNC router, but a band saw or jig saw would do as well. The piston is a plywood plug mounted to a long bolt; [Izzy] gambled a little by cutting the groove for the O-ring with a table saw, but no fingers were lost. The cylinder uses a cheap bungee as a return spring, but an internal compression spring would work too,. Adding a second air inlet to make the cylinder double-acting would be possible as well. The video below shows the cylinder in action as a jig clamp.

True, the valves are the most expensive part of a pneumatic system, but if nothing else, being able to say you made your own cylinders is a win. And maybe you’ll get the fluid-power bug and want to work up to DIY hydraulics.

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What We Need To Try In Haptic Hacks

March 22, 2018 by Steven Dufresne 9 Comments

Looking for ideas for your haptics projects? [Destin] of the Smarter Every Day YouTube channel got a tour from the engineers at HaptX of their full-featured VR glove with amazing haptic feedback both with a very fine, 120-point sense of touch, force feedback for each finger, temperature, and motion tracking.

In hacks, we usually stimulate the sense of touch by vibrating something against the skin. With this glove, they use pneumatics to press against the skin. A single fingertip has multiple roughly 1/8 inch air bladders in contact with it. Each bladder is separately pneumatically controlled by pushing air into it. The air pressure can vary continuously so that the bladders can push lightly, harder or anywhere in between. The glove has 120 of these bladders spread out over the fingers and the palm. Unfortunately, they didn’t allow him to see the valves controlling the pneumatics, but if you are looking for a low-frequency, low-cost way to actuate valves you might consider using syringes. The engineers do tell [Destin] that if your VR scene shows something pressing against your virtual finger, as long as your haptics push against your real finger within around 1/8th of a second, your brain won’t notice the delay.

They’re also working on using hot and cold fluids to give a sense of temperature within a glove. This is demonstrated in the first video below when [Destin] feels heat while a dragon in the VR world breathes fire on his hand. Fortunately one of the engineers mentions that our sense of temperature is one of the slower ones, it can handle longer latencies than even touch. We can see implementing this in a hack using a bladder pressing against the skin while tubes circulate different temperature fluids through it. But maybe there’s a way to do it electrically, possibly with thermoelectric modules as is done with this drinks cooler? Though safety issues might prohibit that.

Other features mentioned are force feedback for each finger, and their custom motion tracking which uses both magnetic and optical means to track fingertips. But we’ll leave the rest to the videos below. The first is the technical tour and the second is the glove being used in the VR world.

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Paper Circuit Does Binary Math With Compressed Air

June 12, 2017 by Dan Maloney 32 Comments

Most of us can do simple math in our heads, but some people just can’t seem to add two numbers between 0 and 3 without using paper, like [Aliaksei Zholner] does with his fluidic adder circuit built completely of paper.

Pneumatic AND gate

There’s some good detail in [Aliaksei]’s translated post on the “Only Paper” forum, a Russian site devoted to incredibly detailed models created entirely from paper. [Aliaksei] starts with the basic building blocks of logic circuits, the AND and OR gates. Outputs are determined by the position of double-headed pistons in chambers, with output states indicated by pistons that raise a flag when pressurized. The adder looks complicated, but it really is just a half-adder and full-adder piped together in exactly the same way it would be wired up with CMOS or TTL gates. The video below shows it in action.

If [Aliaksei]’s name seems familiar, it’s because we’ve featured his paper creations before, including this working organ and a tiny working single cylinder engine. We’re pleased with his foray into the digital world, and we’re looking forward to whatever is next.

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Chocolate Factory Simulation Makes Bars With LEGO

May 29, 2017 by John Baichtal 3 Comments

[Michael Brandl] got to visit the Milka chocolate factory in Bludenz, Austria and was inspired to build this simulation of the production process for the LEGO world 2017 event in Copenhagen.

The process begins with the empty mold riding on a double row of tank treads. Subsequent modules seem to fill the mold with LEGO ingredients, cool the bars, and remove them from the mold. The last two steps rock: [Michael] built a dispenser that drops a tiny cardboard box onto the line, sized to hold 3 LEGO bars. The box rolls to the end of the line and is picked up by a pneumatic gripper that picks up the box and places it on a pallet.

While more whimsical than the LEGO liquid handler we featured recently, there are a lot of interesting robotic techniques to be learned here. On the reverse angle video you can see more of what’s going on with the wiring of the various motors and sensors. There are six EV3 bricks scattered along the length of the assembly line. The bricks control 15 small motors, 2 large motors, 7 touch sensors, and 3 light sensors. [Michael] added some nice touches, like the combo of two color sensors, seen around 1:45 of the reverse angle video, possibly used to keep the factory operations synced.

Check out [Michael’s] Mindstorms sendup of [Anouk Wipprecht’s] drink bot dress. The LEGO version was built for Robotexotica. In addition, he has a lot of projects featured on his site.

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AirLegs Augment Your Cardio By 10%

September 7, 2014 by James Hobson 36 Comments

Here’s another very interesting project to come out of the 4 Minute Mile challenge — pneumatically boosted legs.

It’s another project by [Jason Kerestes] in cooperation with DARPA. We saw his jet pack a few days ago, but this one looks like it has a bit more promise. It is again a backpack mounted system, but instead of a few jet turbines, it has a pneumatic cylinders which move your legs for you.

Just watching it it’s hard to believe it makes it easier to run, but apparently after being tested at the Army Research Laboratories last year it demonstrated a whopping 10% reduction in metabolic cost for subjects running at high speeds. It can actually augment the human running gait cycle, and is the only device the US Army has confirmed can do so.

He is already hard at work designing version 2.0 which is lighter and more flexible. There’s a bunch of test videos after the break so stick around to see it in action.

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