In the closing months of World War II, the Axis and the Allies were throwing everything they had at each other. The tide was turning to the Allies’ favor, but the Germans were showing a surprising resilience, at least in terms of replacing downed fighter and bomber aircraft. When the Allies examined the wreckage of these planes, they discovered the disturbing truth: the planes contained large pieces forged from single billets of metal, which suggested a manufacturing capability none of the Allies possessed and which allowed the Germans to quickly and cheaply make better and faster planes.
When the war was over, the Allies went looking for the tools the Germans had used to make their planes, and found massive closed-die forging presses that could squeeze parts out of aluminum and magnesium alloys in a single step. The Soviets carted off a 30,000 ton machine, while the Americans went home with a shipload of smaller presses and the knowledge that the Russians had an edge over them. Thus began the Heavy Press Program, an ultimately successful attempt by the US military to close a huge gap in strategic manufacturing capabilities that [Machine Thinking] details in the excellent video below.
One doesn’t instantly equate monstrous machines such as the Mesta 50,000-ton press, over nine stories tall with half of it buried underground and attached directly to bedrock, with airplane manufacture. But without it and similar machines that came from the program, planes from the B-52 to the Boeing 747 would have been impossible to build. And this isn’t dead technology by any means; sold to Alcoa in 1982 after having been operated by them for decades, the “Fifty” recently got a $100 makeover after cracks appeared in some castings, and the press and its retro-brethren are still squeezing out parts for fighters as recent as the F-35.
Working with hydraulics usually means having a fluid tank and valves. [consciousflesh] does away with both those for his DIY hydraulic artificial muscles. Instead, he uses a pair of muscles, both preloaded with fluid. To contract one, he pumps the fluid into the other, expanding that one, and vice versa. A bidirectional gear pump moves the fluid while also acting as a valve. And flexible materials replace heavy metal cylinders.
As we said, this is a DIY project. He made the muscles by surrounding silicone tubes with aramid fiber sleeves, giving added strength. The blocks at either end are also custom-made. The gear pump is one he purchased and made substantial modifications to, including removing the tank and fixing a brushless DC motor to one end. The final custom piece was a controller board for the motor. A Gerber file, schematic, and technical drawings, along with further details are all on his Hackaday.io page. Meanwhile, check out the load test in the video below as the muscles lift and lower 5 kg (11 lbs) each.
A search of Hackaday shows hydraulic artificial muscles may be rare, so perhaps this will be the first of many. For example, how about replicating how human arm muscles work together, one contracting while the other expands? We’ve seen that done already using pneumatics with [James Hobson’s] exoskeleton arms. Perhaps someone should do it with these pairs of flexible hydraulic muscles?
[Colin Furze] is back at it – once again shrugging off the confines of feasibility and laughing in the face of sanity, all whilst sporting the signature tie with unrivalled style.
Teaming up with [James Bruton], the result of their collective talent this time is a hydraulic hulkbuster suit, at a frankly ridiculous scale. This is the third and final episode of the build process, with the first two covering the legs and body.
To demonstrate the strength of his latest toy, [Colin] tapes himself to the arm of his creation and promptly gets swung into a wall. We still don’t entirely understand how [Colin] survives his antics, but we’re very glad he does.
The steel frame is a masterclass in welding and fabrication, providing support for three hydraulic pumps, the accompanying rams, some seriously hefty bearings (think 1 m diameter), and one Colin. As if a giant moving steel behemoth wasn’t enough, each arm houses a weapon: a flamethrower and a power-fist. All parts are sourced from eBay.
The control electronics and 3D-printed skin are pretty nifty too – you can see [James]’s first video here.
You can get pretty much any part you need online these days, but some specialty parts are a little hard to come by. So if your needs are esoteric, like tiny hydraulic cylinders for RC snow plows, you might just have to roll your own.
To be honest, we never really knew that realistic working hydraulics on such a small scale were a thing, but [tintek33]’s video below opened our eyes to a new world of miniature mechanicals. You’d think a linear actuator would be a fine stand-in for the hydraulic ram on a tiny snow plow for an RC truck, but apparently no detail is too small to address in painstaking detail. And as with many things in life, the lathe is the way to get there. Every part is scratch-built from raw brass, aluminum and steel on a mini lathe, with the exception of a few operations that were sent over to the mill that could have been done with hand tools in a pinch. The video is longish, so if you’re not into machining you can skip to 16:40 or so and pick the action up at final assembly. The finely finished cylinder is impressively powerful when hooked up to [tintek33]’s hydraulic power pack, and looks great on the plow. He’s got some other videos on his site of the RC snow plow in action that are worth a look, too.
Despite the claims of “free energy” on the title of the video below, this is not yet another wacky perpetual motion story. We here at Hackaday fully support the laws of thermodynamics, and we think you should too. But you have to admit that a pump that works without any apparent energy inputs looks kind of shady at first glance.
The apparatus in question is a ram pump, a technology dating back all the way to the 18th century. The version that [Junkyard – Origin of Creativity] built uses commonly available materials like PVC pipes and fittings. About the only things on the BOM that might be hard to scratch up are the brass check valves, which should probably be flap valves rather than the easier to find spring valves. And the only custom part is an adapter to thread the plastic soda bottle that’s used as an air chamber to the PVC, which a 3D printer could take care of if you choose not to hack a bottle cap like [Junkyard] did. The video below shows the impressive lift achieved just by tapping the kinetic energy of the incoming flow.
Almost every big corporation has a research and development organization, so it came as no surprise when we found a tip about Disney Research in the Hackaday Tip Line. And that the project in question turned out to involve human-safe haptic telepresence robots makes perfect sense, especially when your business is keeping the Happiest Place on Earth running smoothly.
That Disney wants to make sure their Animatronics are safe is good news, but the Disney project is about more than keeping guests healthy. The video after the break and the accompanying paper (PDF link) describe a telepresence robot with a unique hydrostatic transmission coupling it to the operator. The actuators are based on a rolling-diaphragm design that limits hydraulic pressure. In a human-safe system that’s exactly what you want.
The system is a hybrid hydraulic-pneumatic design; two actuators, one powered by water pressure and the other with air, oppose each other in each joint. The air-charged actuators behave like a mass-efficient spring that preloads the hydraulic actuator. This increases safety by allowing the system to be de-energized instantly by venting the air lines. What’s more, the whole system presents very low mechanical impedance, allowing haptic feedback to the operator through the system fluid. This provides enough sensitivity to handle an egg, thread a needle — or even bop a kid’s face with impunity.
Wood. Humans have burned it for to heat their homes for thousands of years. It’s truly a renewable source of energy. While it may not be the most efficient or green method to warm a space, it definitely gets the job done. Many homes still have a fireplace or wood burning stove for supplemental heat. For those in colder climates, wood is more than just supplemental, it’s needed simply for survival.
The problem with firewood is that it doesn’t come ready to burn. Perfect fireplace sized chunks don’t grow on trees after all. The trees have to be cut up into logs. The logs must be split. The split wood then needs to dry for 6 months or so.
Anyone who’s spent time manually splitting wood can tell you it’s back breaking work. Swinging an 8 pound maul for a few hours will leave your hands numb and your shoulders aching. It’s the kind of work that leaves the mind free to wander a bit. The hacker’s mind will always wander toward a better way to get the job done. Curiously we haven’t seen too many log splitting hacks here on the blog. [KH4] built an incredible cross bladed axe back in 2015, but that’s about it.