MRRF: Tasty Filament from Proto-Pasta

Alongside printers from all walks of manufacturing, one can naturally expect to find people selling different kinds of filament at a 3D printing festival. One of these purveyors of plastic was Proto-pasta out of Vancouver, WA. Proto-pasta prides themselves on unique offerings and complete transparency about their manufacturing processes.

Almost all of their filaments are either PLA or HTPLA with something special added during extrusion. The menu includes steel, iron, carbon, and finely ground coffee. The coffee filament was one of our favorites for sure. The print they brought with them looked solidified light roast and had a transparent kind of lollipop quality to it. I couldn’t detect the coffee scent due to allergies, but [Alex] assured me that printing with this filament will make your house or hackerspace smell terrific.

[Alex] was giving away samples of their stainless steel composite PLA. This one can be polished to a smooth shine with a series of papers that run from 400 to 8,000-grit. Another of their newer offerings is PLA infused with magnetic iron particles. Prints made with this stuff can be rusted to achieve an antique, steampunk, or shabby chic aesthetic.

Proto-pasta also has an electrically conductive composite carbon PLA. This one is great for capacitive applications like making a custom, ergonomic stylus or your own game controller. According to the site, the resistivity of printed parts is 30 ohms per centimeter as measured perpendicular to the layers, and 115 ohms along the layers.

Have you made anything awesome with conductive or magnetic filament? Have you had any problems with unorthodox filaments? Let us know in the comments.

Laser Removes Rust Like Magic

If you’ve worked with steel or iron, you will be very familiar with rust. You will have an impressive armoury of wire brushes and chemicals to deal with it, and your sandblasting guy is probably in your speed-dial list.

We’ve had more than one Hackaday reader contact us of late with videos showing an apparently miraculous handheld laser unit effortlessly stripping away rust, and leaving a near-perfect surface with little mess. Can it be real, they ask, is it an internet hoax? After all if you have done battle with the dreaded iron oxide you’ll know there is no miracle fix to the problem, however you deal with it there has traditionally been hard work involved.

So after a bit of research, we find CleanLaser, the German company whose products feature in the videos. Quoting their website: “Powerful, very short, rapid and moving laser pulses produce micro-plasma bursts, shockwaves and thermal pressure resulting in sublimation and ejection of the target material”. So yes, it seems they’re real.

The website is at pains to stress the environmental benefits of the devices over comparable sandblasting or similar technologies, but has very little information on their safety. They are available in power ratings from 12W to 1KW which is a hell of a lot of laser power to be projecting, yet the operators seem only to be wearing goggles. Perhaps this comes back to the “Powerful, very short, rapid and moving” bit in the quote above, is there no point source to sear your retina? Laser experts please enlighten us in the comments.

If you work with metal or grew up in a metalworking business, this machine probably has you salivating. Sadly for hackers and makers though it’s probable that it and ones like it will be out of our price range for quite some time. Still, the prospect of a guy with one in an industrial unit appearing in most towns can’t be too far away, and that can only be a good thing

The video shows the machine in action. Rusty fire-grate in, perfect shiny surface out. Perhaps only those of you who have spent many hours with a wire brush will understand.

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3D Printing Metal from Rust

It seems backwards, but engineers from Northwestern University have made 3D printing metal easier (and eventually cheaper) by adding extra production steps to the procedure. (Paper available in PDF).

Laser sintering works by laying down a thin layer of metal powder and then hitting it with a strong enough laser to sinter the particles together. (Sintering sticks the grains together without getting the metal hot enough to melt it.) The rapid local heating and cooling required to build up 3D objects expands and cools the metal, and can result in stresses inside the resulting object.

The Northwestern team still lays down layers of powder, but glues the layers together with a quick-drying polymer instead of fusing them with a laser. Once the full model is printed, they then sinter it in one piece in an oven.

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3D-printed copper lattice. Credit: Ramille Shah and David Dunand

The advantages of adding this extra step are higher printing speed — squirting the liquid out of syringe heads can be faster than fusing metal particles with a laser — and increased structural integrity because the whole model is heated and cooled at one time. A fringe benefit is that the model is still a bit flexible before firing, opening up possibilities for printing a flat model and then bending it into shape before sintering.

And if that weren’t enough, the team figured that they’d add a third step to the procedure to allow it to be used with rust (iron oxide) as the starting powder. They print the rust and polymer model, then un-rust the iron using hydrogen, and then fire it as before. Why rust? Do you know anything cheaper to use as a raw material?

What do you think? The basic idea may even be DIYable — glue metal particles together and heat them up enough to stick. Not in my microwave oven, though. We’d love to see a more energy-efficient 3D metal printer.

Thanks to [Joe] for the tip!

Programming with Rust

Do hardware hackers need a new programming language? Your first answer might be no, but hold off a bit until you hear about a new language called Rust before you decide for sure.

We all know real hackers use assembly language to program CPUs directly, right? Well, most of us don’t do as much assembly language as we used to do. Languages like C can generate tight, predictable code and are easier to manage.

Although some people use more abstract languages in some embedded systems, it is no secret that for real-time systems, device driver development, and other similar tasks, you want a language that doesn’t obscure underlying details or generate code that’s difficult to reason about (like, for example, garbage collection). It is possible to use special techniques (like the Real-Time Java Specification) to help languages, but in the general case a lean language is still what most programmers reach for when you have to program bare metal.

Even C++, which is very popular, obscures some details if you use things like virtual functions (a controversial subject) although it is workable. It is attractive to get the benefit of modern programming tools even if it does conceal some of the underlying code more than straight C.

About Rust

That’s where Rust comes in. I could describe what Rust attempts to achieve, but it is probably easier to just quote the first part of the Rust documentation:

Rust is a systems programming language focused on three goals: safety, speed, and concurrency. It maintains these goals without having a garbage collector, making it a useful language for a number of use cases other languages aren’t good at: embedding in other languages, programs with specific space and time requirements, and writing low-level code, like device drivers and operating systems. It improves on current languages targeting this space by having a number of compile-time safety checks that produce no runtime overhead, while eliminating all data races. Rust also aims to achieve ‘zero-cost abstractions’ even though some of these abstractions feel like those of a high-level language. Even then, Rust still allows precise control like a low-level language would.

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Rusty old table saw turned into a workstation worthy of a master craftsman

rusty-old-table-saw-turned-pro-workstation

Okay, first of all: holy crap! Even if you didn’t know this started as a rusty table saw, the workstation that came out of this project is just phenomenal. It really makes us wish we had looked around for a used model with a cast iron top instead of going for the cheap stamped metal one that was ready to use.

[Simon Leblanc] started with a Delta contractor’s saw that was rusty inside and out. The refurbishment began by removing the table and everything from the inside. The rods and gears were all cleaned up before he began to sand away the rust on the table itself. But obviously he didn’t stop with getting the saw to be functional again. He built a small set of cabinets to serve as the base for the saw. They went inside of this larger assembly that combines an MDF table top with an Accusquare rip fence to greatly increase the working surface of the tool.

Now he needs to start in on an extra fancy CNC jig for the thing.

[via Reddit]