UC Berkeley Prints Glass Nanoparticles

August 15, 2024 by Al Williams 8 Comments

In a recent video, [Joel] of 3D Printing Nerd interviews a researcher at University of California, Berkeley about their work with glass 3D printing technology. A resin is impregnated with tiny glass nanoparticles and produces green parts. An oven burns away the resin and then another heating step produces the actual silica glass part. You can see a video about the process below.

As you might expect with glass, the temperatures are toasty. The first burn is at 1100 C and the fusing burn is at 1300 C. The nanoparticles are about 40 nanometers across. The resulting parts are tiny with very small feature sizes. The technology to do this has been around for a few years, and the University continues researching this form of computed axial lithograph (CAL) 3D printing. These parts are so small that it uses an adaptation called microCAL that produces much smaller parts at high precision. However, the equipment available today won’t produce very large objects. The video talks about the uses for some of these small glass items.

We wonder how much the firings in the ovens change the tiny tolerances. They obviously work, so either they account for that or it doesn’t shrink much.

If you want your own 3D printed glass, a laser system might be more practical. If you just want transparent plastic, your FDM printer can do that. Really.

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Stemfie, The 3D-Printable Construction Set

August 13, 2024 by Lewin Day 3 Comments

Construction kit toys are cited by many adults as sparking great creativity and engineering talent in their youth. LEGO, Meccano, K’NEX, Lincoln Logs—these are all great commercial options. But what about printing your very own construction kit at home? Meet Stemfie.

Fundamentally, Stemfie isn’t that different from any other construction kit you might have seen before. It has various beams and flat plates that are full of holes so they can be assembled together in various ways. It also uses bolts, spacers, and small plastic nuts that can be tightened using a special hand tool. Think of a mixture between LEGO Technic and Meccano and that will get you in the ballpark. It includes neat motion components too, including gears, wheels, and even a large flat spring!

What can you build with it? Well, as every construction kit toy says, you’re only limited by your imagination! However, if your imagination is especially small, you can just use the Stemfie 3D YouTube channel for inspiration. It features everything from a ping pong ball catapult to a rubber-band driven car. Plus, since it’s all 3D printed, you can simply scale up the parts and build even bigger designs. Like a giant catapult that can hurl entire water jugs. Fun!

We’ve seen other projects in this vein before. One of our favorites is [Ivan Miranda]’s giant 3D printed assembly kit that he uses to build big monster toys.

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Globe-Shaped World Clock Is A 3D-Printed Mechanical Marvel

August 12, 2024 by Lewin Day 5 Comments

Time zones are a complicated but necessary evil. Humans like the numbers on the clock to vaguely match up with what the sun is doing in the sky outside. To that end, different places in the world keep different time. If you want to keep track of them in a very pretty fashion, you might consider building a fancy and beautiful World Clock like [Karikuri] did.

The design is based around a globe motif, mimicking the world itself. Only, on the surface of the globe, there are clock faces instead of individual countries. Each clock runs to its own time, directed by a complicated assemblage of 3D-printed gears. Mechanical drive is sent to the globe from a power base, which itself carries a mechanical seven-segment display. This too can display the time for different regions by using the controls below. It’s also useful for setting the clock to the correct time.

It’s a little difficult to follow the build if you don’t speak Japanese. However, quality subtitles are available in English if you choose to enable them.

We’ve seen [Karikuri’s] work before. We’ve also featured a great many world clocks over the years, including this particularly beautiful example that tracks night and day. Just don’t expect it to keep track of moon time. Video after the break.

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Prusa Picks Up The Pace With New MK4S Printer

August 12, 2024 by Tom Nardi 28 Comments

One of the things you’re paying for when you buy a 3D printer from Prusa Research is, essentially, your next 3D printer. That’s because Prusa’s machines are designed to be upgraded and modified as time goes on. An upgrade kit is always released to allow each older printer to be converted into its successor, and while there’s occasionally been some debate about whether or not it’s the most cost-effective choice, at least it is a choice you have as an owner.

If you’ve got a Prusa MK4, you’ll soon get to make that decision for yourself. Announced earlier today, the new MK4S brings some notable changes to last year’s printer. The $99 upgrade is scheduled to be available by the end of the month for existing owners, but if you’ve been on the fence about joining Team Orange and Black, you can purchase the MK4S right now in both kit and assembled forms for the same price ($799 and $1,099 respectively) as the previous MK4.

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3D Printed Jet Engine Goes Turbo

August 10, 2024 by Al Williams 12 Comments

Printing a model jet engine is quite an accomplishment. But it wasn’t enough for [linus3d]. He wanted to redesign it to have a turbojet, an afterburner, and a variable exhaust nozzle. You can see how it all goes together in the video below.

This took months of work and it shows. This probably won’t make a good rainy-day weekend project. You do need a few ball bearings and some M2 hardware, but it is mostly 3D printed.

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Liquid (Reversibly) Solidifies At Room Temperature, Gets Used For 3D Prints

August 9, 2024 by Donald Papp 8 Comments

Researchers demonstrate sustainable 3D printing by using poly(N-isopropylacrylamide) solutions (PNIPAM), which speedily and reliably turn solid by undergoing a rapid phase change when in a salt solution.

This property has been used to 3D print objects by using a syringe tip as if it were a nozzle in a filament-based printer. As long as the liquid is being printed into contact with a salt solution, the result is a polymer that solidifies upon leaving the syringe.

What’s also interesting is that the process by which the PNIPAM-based solutions solidify is entirely reversible. Researchers demonstrate printing, breaking down, then re-printing, which is an awfully neat trick. Finally, by mixing different additives in with PNIPAM, one can obtain different properties in the final product. For example, researchers demonstrate making conductive prints by adding carbon nanotubes.

While we’ve seen the concept of printing with liquids by extruding them into a gel bath or similar approach, we haven’t seen a process that prides itself on being so reversible before. The research paper with all the details is available here, so check it out for all the details.

Magnesium And Copper Makes An Emergency Flashlight

August 8, 2024 by Lewin Day 17 Comments

Many of us store a flashlight around the house for use in emergency situations. Usually, regular alkaline batteries are fine for this task, as they’ll last a good few years, and you remember to swap them out from time to time. Alternatively, you can make one that lasts virtually indefinitely in storage, and uses some simple chemistry, as [JGJMatt] demonstrates.

The flashlight uses 3D printing to create a custom battery using magnesium and copper as the anode and cathode respectively. Copper tape is wound around a rectangular part to create several cathode plates, while magnesium ribbon is affixed to create the anodes. Cotton wool is then stuffed into the 3D-printed battery housing to serve as a storage medium for the electrolyte—in this case, plain tap water.

The custom battery is paired with a simple LED flashlight circuit in its own 3D-printed housing. The idea is that when a blackout strikes, you can assemble the LED flashlight with your custom battery, and then soak it in water. This will activate the battery, producing around 4.5 V and 20 mA to light the LED.

It’s by no means going to be a bright flashlight, and realistically, it’s probably less reliable than just keeping a a regular battery-powered example around. Particularly given the possibility of your homebrew battery corroding over the years unless it’s kept meticulously dry. But that’s not to say that water-activated batteries don’t have their applications, and anyway it’s a fun project that shows how simple batteries really are at their basic level. Consider it as a useful teaching project if you have children interested in science and electricity!