It’s a sad day when one of the simplest and generally most reliable tools in the shop – the bench vise – gives up the ghost. With just a pair of beefy castings and a heavy Acme screw, there’s very little to go wrong with a vise, but when it happens, why not take it as an opportunity to make your own? And, why not eschew the screw and go hydraulic instead?
That’s the path [Darek] plotted when his somewhat abused vise reached end-of-life with an apparently catastrophic casting failure. His replacement is completely fabricated from steel bar and channel stock, much of it cut on his nifty plasma cutter track. The vice has a fixed base and rear jaw, with a moving front jaw. Hiding inside is a 5-ton single-acting hydraulic cylinder. A single acting cylinder won’t open the vise on its own, so [Darek] came up with a clever return mechanism: a pair of gas springs from a car trunk.
With a pair of hardened steel jaws, some modifications to the power cylinder to allow foot operation, and a spiffy paint job, the vise was ready for service. Check out the build in the video below; we’re impressed with the power the vise has, and hands-free operation is an unexpected bonus.
Yes, most people buy vises, but from the small to the large, it’s nice to see them built from scratch too.
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.
These Fluid Displacement Thermal Actuators designed by [Andrew Benson] are a delightful and profoundly different approach to the Power Harvesting Challenge portion of The Hackaday Prize. While most projects were focused on electrical power, [Andrew]’s design is essentially a mechanical motor that harnesses the fact that Phase Change Materials (PCMs) change volume when they go from liquid to solid or vice-versa; that property is used to provide a useful hydraulic force. In short, it’s a linear actuator that retracts and expands as the PCM freezes or melts. By choosing a material with melting and freezing temperatures that are convenient for the operating environment, an actuator can be reliably operated virtually for free. A proof of concept is the device shown here; a model of a sun-shade that deploys when a certain temperature is reached and retracts when it has cooled.
Turning temperature changes into useful physical work is the principle behind things like wax motors and even some self-winding clocks, but what [Andrew] has done is devise a useful method of interfacing directly to the fluids; abstracting away the materials themselves in order to provide mechanical power on the other end. These devices, in general, may not be particularly efficient but they have very few moving parts, are astonishingly reliable, and can operate at virtually any scale. [Andrew] has been thinking big, many of his application ideas are architectural in nature.
[Andrew] was inspired to enter his design for The Hackaday Prize, and we’re glad he did because it was selected as one of the finalists in the Power Harvesting Challenge, and will be in the running for the $50,000 Grand Prize. If you also have an idea waiting for an opportunity to shine, now is the time. The Human-Computer Interface Challenge is up next, followed by the Musical Instrument Challenge. All you really need to enter is a documented concept, so sharpen your pencils and give your idea a shot at reaching the next level.
When making a toy excavator arm, or any robotic arm, the typical approach is to put motors at the joints, or if there isn’t room, to put the motors somewhere else and transfer the force using fishing line and pulleys. [Navin Khambhala] chose instead to do it more like the real excavators, with hydraulics using syringes. And we have to admit, the result it pretty elegant in its simplicity.
The syringes do the job of single-acting hydraulic actuators, one at the motor and the other where the force is needed. In between them, what appears to be clear vinyl tubes carry the fluid between syringes. 12 volt DC motors with bolts on them move nuts attached to the syringe pistons to push and pull the pistons. It is so simple that no further explanation is needed, though like most apparently simple things, we’re sure a lot of effort went into making it that way. The video below shows the finished product, as well as walks through the making of it.
When your project needs power, you might need to turn to hydraulics. There is a lot of mystery about fluid power, but there is also a huge supply chain devoted to getting you the parts you need to power your project. Off-the-shelf components may not fit your application though, in which case it might be handy to know how to build your own custom hydraulic cylinders.
While it’s true that custom cylinder builds are pretty common, it’s still interesting to see the process [MakeItExtreme] used. Starting with an off-the-shelf piston and gland, this double-acting cylinder build is a pretty straightforward exercise in machining. The cylinder is threaded at the rod end and a cap is welded onto the piston end. Threaded bosses for fittings are welded on, the business end of the rod is threaded, and everything is assembled. The cylinder turned out to be pretty powerful as the video below shows.
As a product of the prolific team at [MakeItExtreme], we can tell this cylinder is destined for another even more interesting build. It’s hard to guess where this one will end up, but we’ll bet it ends up in another tool in their shop. Maybe it end up powering a beefed-up version of their recent roll bender.
The idea is simple. The team started with a printer that uses a liquid ink that is UV cured to produce solid layers. The printer has the ability to use multiple liquids, and [MacCurdy] uses hydraulic fluid (that does not UV cure) as one of the print materials. Just as you can use a 3D printer to build structures within other structures, printing the hydraulics allows for complex closed systems that use the UV-cured resin as mechanical parts that can transfer pressure to and from the hydraulic system.