This film is another classic of mid-century corporate communications that was typically shown in schools, which the sponsor — in this case Shell Oil — seeks to make a point about the inevitable march of progress, and succeeds mainly in showing children and young adults what lay in store for them as they entered a working world that needed strong backs more than anything.
Despite the narrator’s accent, the factories shown appear to be in England, and the work performed therein is a brutal yet beautiful ballet of carefully coordinated moves. The sheer power of the slabbing mills at the start of the film is staggering, especially when we’re told that the ingots the mill is slinging about effortlessly weigh in at 14 tons apiece. Seeing metal from the same ingots shooting through the last section of a roller mill at high speed before being rolled into coils gives one pause, too; the catastrophe that would result if that razor-sharp and red-hot metal somehow escaped the mill doesn’t bear imagining. Similarly, the wire drawing process that’s shown later even sounds dangerous, with the sound increasing in pitch to a malignant whine as the die diameter steps down and the velocity of the wire increases.
There are the usual charming anachronisms, such as the complete lack of safety gear and the wanton disregard for any of a hundred things that could instantly kill you. One thing that impressed us was the lack of hearing protection, which no doubt led to widespread hearing damage. Those were simpler times, though, and the march of progress couldn’t stop for safety gear. Continue reading “Retrotechtacular: The Drama Of Metal Forming”→
Transformers have an obvious use for increasing or decreasing the voltage in AC systems, but they have many other esoteric uses as well. Electric motors and generators are functionally similar and can be modeled as if they are transformers, but the truly interesting applications are outside these industrial settings. Wireless charging is essentially an air-core transformer that allows power to flow through otherwise empty space, and induction cooking uses a similar principle to induce current flow in pots and pans. And, in this case, coffee mugs.
[Sajjad]’s project is an effort to keep his coffee warm while it sits on his desk. To build this special transformer he places his mug inside a coil of thick wire which is connected to a square wave generator. A capacitor sits in parallel with the coil of wire which allows the device to achieve resonance at a specific tuned frequency. Once at that frequency, the coil of wire efficiently generates eddy currents in the metal part of the coffee mug and heats the coffee with a minimum of input energy.
While this project doesn’t work for ceramic mugs, [Sajjad] does demonstrate it with a metal spoon in the mug. While it doesn’t heat up to levels high enough to melt solder, it works to keep coffee warm in a pinch if a metal mug isn’t available. He also plans to upgrade it so it takes up slightly less space on his desk. For now, though, it can easily keep his mug of coffee hot while it sits on his test bench.
Resin 3D printers have a significant advantage over filament printers in that they are able to print smaller parts with more fine detail. The main downside is that the resin parts aren’t typically as strong or durable as their filament counterparts. For this reason they’re often used more for small models than for working parts, but [Breaking Taps] wanted to try and improve on the strength of these builds buy adding metal to them through electroplating.
Both copper and nickel coatings are used for these test setups, each with different effects to the resin prints. The nickel adds a dramatic amount of stiffness and the copper seems to increase the amount of strain that the resin part can tolerate — although [Breaking Taps] discusses some issues with this result.
While the results of electroplating resin are encouraging, he notes that it is a cumbersome process. It’s a multi-step ordeal to paint the resin with a special paint which helps the metal to adhere, and then electroplate it. It’s also difficult to ensure an even coating of metal on more complex prints than on the simpler samples he uses in this video.
After everything is said and done, however, if a working part needs to be smaller than a filament printer can produce or needs finer detail, this is a pretty handy way of adding more strength or stiffness to these parts. There’s still some investigating to be done, though, as electroplated filament prints are difficult to test with his setup, but it does show promise. Perhaps one day we’ll be able to print with this amount of precision using metal directly rather than coating plastic with it.
I’ve always thought that there are three things you can do with metal: cut it, bend it, and join it. Sure, I knew you could melt it, but that was always something that happened in big foundries- you design something and ship it off to be cast in some large angular building churning out smoke. After all, melting most metals is hard. Silver melts at 1,763 °F. Copper at 1,983 °F. Not only do you need to create an environment that can hit those temperatures, but you need to build it from materials that can withstand them.
Turns out, melting metal is not so bad. Surprisingly, I’ve found that the hardest part of the process for an engineer like myself at least, is creating the pattern to be replicated in metal. That part is pure art, but thankfully I learned that we can use technology to cheat a bit.
When I decided to take up casting earlier this year, I knew pretty much nothing about it. Before we dive into the details here, let’s go through a quick rundown to save you the first day I spent researching the process. At it’s core, here are the steps involved in lost wax, or investment, casting:
Make a pattern: a wax or plastic replica of the part you’d like to create in metal
Make a mold: pour plaster around the pattern, then burn out the wax to leave a hollow cavity
Pour the metal: melt some metal and pour it into the cavity
I had been kicking around the idea of trying this since last fall, but didn’t really know where to begin. There seemed to be a lot of equipment involved, and I’m no sculptor, so I knew that making patterns would be a challenge. I had heard that you could 3D-print wax patterns instead of carving them by hand, but the best machine for the job is an SLA printer which is prohibitively expensive, or so I thought. Continue reading “How To Get Into Lost Wax Casting (with A Dash Of 3D Printing)”→
Refining precious metals is not as simple as polishing rocks that have been dug out of the ground. Often, complex chemical processes are needed to process the materials properly or in high quantities, but these processes leave behind considerable waste. Often, there are valuable metals left over in these wastes, and [NerdRage] has gathered his chemistry equipment to demonstrate how it’s possible to recover these metals.
The process involved looks to recover copper and nitric acid from copper nitrate, a common waste byproduct of processing metal. While a process called thermal decomposition exists to accomplish this, it’s not particularly efficient, so this alternative looks to improve the yields you could otherwise expect. The first step is to react the copper nitrate with sulfuric acid, which results in nitric acid and copper sulfate. From there, the copper sulfate is placed in an electrolysis cell using a platinum cathode and copper anodes to pass current through it. After the process is complete, all of the copper will have deposited itself on the copper electrodes.
The other interesting thing about this process, besides the amount of copper that is recoverable, is that the sulfuric acid and the nitric acid are recoverable, and able to be used again in other processes. The process is much more efficient than thermal decomposition and also doesn’t involve any toxic gasses either. Of course, if collecting valuable metals from waste is up your alley, you can also take a look at recovering some gold as well.
It’s a cliche that the only machine tool that can make copies of itself is the lathe. It’s not exactly true, but it’s a useful adage in that it points out that the ability to make big round things into smaller round things, and to make unround things into round things, is a critical process in so many precision operations. That said, making a lathe primarily out of wood presents some unique challenges in the precision department
This isn’t [Uri Tuchman]’s first foray into lathe-building. Readers may recall the quirky creator’s hybrid treadle-powered and electric lathe, also primarily an exercise in woodworking. That lathe has seen plenty of use in [Uri]’s projects, turning both wood and metal stock into parts for his builds. It wasn’t really optimal for traditional metal turning, though, so Mini-Lathe 2 was undertaken. While the bed, headstock, and tailstock “castings” are wood — gorgeously hand-detailed and finished, of course — the important bits, like the linear slides for the carriage and the bearings in the headstock, are all metal. There’s a cross-slide, a quick-change tool post, and a manual lead screw for the carriage. We love the finely detailed brass handcranks, which were made on the old lathe, and all of the lovely details [Uri] always builds into his projects.
Sadly, at the end of the video below we see that the lathe suffers from a fair amount of chatter when turning brass. That’s probably not unexpected — there’s not much substitute for sheer mass whenit comes to dampening vibration. We expect that [Uri] will be making improvements to the lathe in the coming months — he’s not exactly one to leave a job unfinished.
How cool would it be if there was a material that couldn’t be cut or drilled into? You could make the baddest bike lock, the toughest-toed work boots, or the most secure door. Really, the list of possibilities just goes on and on.
Proteus chews through an angle grinder disc in seconds.
The material is made of aluminium foam that’s embedded with a bunch of small ceramic spheres. It works by inducing retaliatory vibrations into the cutting tools, which turns the tools’ force back on themselves and quickly dulls their edges.
The creators have named the material Proteus after the elusive and shape-shifting prophet of Greek mythology who would only share his visions of the future with those who could get their arms around him and keep him still. It sounds like this material could give Proteus a run for his money.
The ceramic spheres themselves aren’t indestructible, but they’re not supposed to be. Abrading the spheres only makes Proteus stronger. As the cutting tool contacts them, they’re crushed into dust that fills the voids in the aluminium foam, strengthening the material’s destructive vibratory effect. The physical inspiration for Proteus comes from protective hierarchical structures in nature, like the impact-resistant rind of grapefruit and the tendency of abalone shells to resist fracture under the impact of shark teeth.
How It’s Made
Proteus recipe in pictures.
At this point, Proteus is a proof of concept. Adjustments would likely have to be made before it can be produced at any type of scale. Even so, the recipe seems pretty straightforward. First, an aluminium alloy powder is mixed with a foaming agent. Then the mixture is cold compacted in a compressor and extruded in dense rods. The rods are cut down to size and then arranged along with the ceramic spheres in a layered grid, like a metallurgical lasagna.
The grid is spot-welded into a steel box and then put into a furnace for 15-20 minutes. Inside the furnace, the foaming agent releases hydrogen gas, which introduces voids into the aluminium foam and gives it a cellular structure.
Effects of cutting into a cylinder of Proteus with an angle grinder.
According to their paper, the researchers tried to penetrate the material with an angle grinder, a water jet cutter, and a drill. Of these, the drill has the best chance of getting through because the small point of contact can find gaps more easily, so it’s less likely to hit a ceramic sphere. The researchers also made cylindrical samples without steel cladding which they used to test the compressive strength and prove Proteus’ utility as a structural material for beams and columns. It didn’t fare well initially, but became less compressible as the foam matrix collapsed.
The creation process lends some leeway for customization, because the porosity of the aluminium foam can be varied by changing the bake time. As for the drill bit problem, tightening up security is as easy as adjusting the size and/or density of the ceramic spheres.
In the video after the break, you can watch a chunk of Proteus eat up an angle grinder disc in under a minute. Some may argue about the tool wielder’s technique, but we think there’s something to be said for any material that can destroy a cutting disc that fast. They don’t claim that Proteus is completely impenetrable, but it does look impressive. We wish they would have tried more cutting tools like a gas torch, or experimented with other destructive techniques, like plastic explosives, but we suppose that research budgets only go so far.
