RepRapMicron Promises Micro-fabrication For Desktops With New Prototype

August 22, 2025 by Donald Papp 10 Comments

3D printing has transformed how hobbyists fabricate things, but what additional doors would open if we could go even smaller? The µRepRap (RepRapMicron) project aims to bring fabrication at the micron and sub-micron scale to hobbyists the same way RepRap strove to make 3D printing accessible. New developments by [Vik Olliver] show a promising way forward, and also highlight the many challenges of going so small.

How exactly would a 3D printer do micro-fabrication? Not by squirting plastic from a nozzle, but by using a vanishingly tiny needle-like effector (which can be made at any workbench via electrochemical erosion) to pick up a miniscule amount of resin one dab a time, curing it with UV after depositing it like a brush deposits a dot of ink.

By doing so repeatedly and in a structured way, one can 3D print at a micro scale one “pixel” (or voxel, more accurately) at a time. You can see how small they’re talking in the image in the header above. It shows a RepRapMicron tip (left) next to a 24 gauge hypodermic needle (right) which is just over half a millimeter in diameter.

Moving precisely and accurately at such a small scale also requires something new, and that is where flexures come in. Where other 3D printers use stepper motors and rails and belts, RepRapMicron leverages work done by the OpenFlexure project to achieve high-precision mechanical positioning without the need for fancy materials or mechanisms. We’ve actually seen this part in action, when [Vik Olliver] amazed us by scribing a 2D micron-scale Jolly Wrencher 1.5 mm x 1.5 mm in size, also visible in the header image above.

Using a tiny needle to deposit dabs of UV resin provides the platform with a way to 3D print, but there are still plenty of unique problems to be solved. How does one observe such a small process, or the finished print? How does one handle such a tiny object, or free it from the build platform without damaging it? The RepRapMicron project has solutions lined up for each of these and more, so there’s a lot of discovery waiting to be done. Got ideas of your own? The project welcomes collaboration. If you’d like to watch the latest developments as they happen, keep an eye on the Github repository and the blog.

CAL 3D Printing Spins Resin Right Round, Baby

August 21, 2025 by Tyler August 8 Comments

Computed Axial Lithography (CAL) is a lighting-fast form of volumetric 3D printing that holds incredible promise for the future, and [The Action Lab] filmed it in action at a Berkeley team’s booth at the “Open Sauce” convention.

The basic principle works like this: an extra-viscous photopolymer resin sits inside a rotating, transparent cylinder. As the cylinder rotates, UV light is projected into the resin in patterns carefully calculated to reproduce the object being printed. There are no layers, no FEP, and no stop-and-start; it’s just one long exposure from what is effectively an object-generating video, and it does not take long at all. You can probably guess that the photo above shows a Benchy being created, though unfortunately, we’re not told how long it took to produce.

Don’t expect to grab a bottle of SLA resin to get started: not only do you need higher viscosity, but also higher UV transmission than you get from an SLA resin to make this trick work. Like regular resin prints, the resolution can be astounding, and this technique even allows you to embed objects into the print.

This handle was printed directly onto the shaft of the screwdriver.

It’s not a new idea. Not only have we covered CAL before, we even covered it being tested in zero-G. Floating in viscous resin means the part couldn’t care less about the local gravity field. What’s interesting here is that this hardware is at tabletop scale, and looks very much like something an enterprising hacker might put together.

Indeed, the team at Berkeley have announced their intention to open-source this machine, and are seeking to collaborate with the community on their Discord server. Hopefully we’ll see something more formally “open” in the future, as it’s something we’d love to dig deeper into — and maybe even build for ourselves.

Thanks to [Beowulf Shaeffer] for the tip. If you are doing something interesting with photopolymer ooze (or anything else) don’t hesitate to let us know! Continue reading “CAL 3D Printing Spins Resin Right Round, Baby” →

Hide Capacitive Touch Buttons In Your Next 3D Print

August 20, 2025 by Donald Papp 14 Comments

Capacitive touch sensors are entirely in the domain of DIY, requiring little more than a carefully-chosen conductive surface and a microcontroller. This led [John Phillips] to ask why not embed such touch buttons directly into a 3D print?

Button locations and labels can be made as part of the 3D print, which is handy.

The process is not much different from that of embedding hardware like magnets or fasteners into 3D prints: one pauses the print at convenient spot, drops in the necessary hardware, then resumes printing. It’s more or less the same for embedding a touch-sensitive button, but [John] has a few tips to make things easier.

[John] suggests using a strip of copper tape, one per touch pad, and embedding it into the print near the surface. His preference is three layers in, putting the copper tape behind 0.6 mm of plastic when using standard 0.20 mm layer heights.

Copper tape makes a good capacitive touch sensor, and the adhesive on the tape helps ensure it stays in place as the 3D printer seals it in on subsequent passes.

Copper tape is also easy to solder to, so [John] leaves a small hole over the copper — enough to stick in a wire and tack it down with the tip of a soldering iron and a blob of solder after the print is complete. It might not be ideal soldering conditions, but if things get a little melty on the back side it’s not the end of the world.

On the software side capacitive touch sensors can be as simple as using an Arduino library for the purpose but [John] rolled his own code, so give it a peek.

This reminds us a bit of another way to get a capacitive touch sensor right up against some plastic: a simple spring can do the trick.

I, 3D Printer

August 18, 2025 by Al Williams 2 Comments

Like many of us, [Ben] has too many 3D printers. What do you do with the old ones? In his case, he converted it into a robotic camera rig. See the results, including footage from the robot, in the video below. In addition to taking smooth video, the robot can spin around to take photos for photogrammetry.

In fact, the whole thing started with an idea of building a photogrammetry rig. That project didn’t go as well as planned, but it did lead to this interesting project.

Continue reading “I, 3D Printer” →

Should You Try Printing With Polypropylene?

August 18, 2025 by Tyler August 10 Comments

Of all the plastics that surround us on the daily, the one we hear least about in the 3D printing world is probably polypropylene (PP). Given that this tough, slightly flexible thermoplastic has characteristics you might want for your prints, the question is: why? [Lost in Tech] is not answering that question in a recent video; instead he’s showing us what we’re missing out on with a review of the material.

A look at the Material Safety Data Sheet and available material has [Lost in Tech] suggesting it won’t be (much) more toxic for you than PLA, but you still wouldn’t want to huff the fumes. The biggest issue printing PP is getting it to stick — glass beds and PEI are not your friend, but polypropylene tape is easy to find and makes a fine print surface. He reviews a few other options, but it looks like plain old tape is still your best bet if you can’t get a hold of a Prusa PP bed. The other big issue is shrinkage, but that’s hardly unique to PP and can be accounted for in the model.

Just because it can be used, that doesn’t mean it should be. [Lost in Tech] does make a good case for why you might want to use PP — for one thing, it doesn’t string much, in part because it’s not hygroscopic. That makes it great for those of us in humid climes who don’t want to always faff around with dry boxes, but also wonderful for parts that will be in touch with water. Polypropylene also has great chemical resistance for even scarier chemicals than dihydrogen monoxide. The “killer app” though, at least as far as [Lost in Tech] is concerned, is to use polypropylene with compliant mechanisms: it’s incredibly resilient to bending, and doesn’t fatigue easily. You might even call it a “flexible” filament, but unlike with TPU, you get a nice hard plastic to go with that flexibility.

If you’re interested in this somewhat-forgotten filament, we featured a “getting started” guide last year. You can even make your own polypropylene filament using non-medical “COVID” masks, but do be sure to wash them first. What do you think? Is it time to give PP another chance, or has the 3D printing world moved on? Continue reading “Should You Try Printing With Polypropylene?” →

MorPhlex: The TPU Filament That Goes Soft After You Print It

August 16, 2025 by Maya Posch 5 Comments

In FDM 3D printing cycles TPU is a bit of a special filament. Not so much because of its properties, but because it’s rather stretchy even as a filament, which makes especially printing certain hardness grades of TPU into somewhat of an nightmare. An interesting new contender here comes from a company called BIQU, who reckon that their ‘MorPhlex’ TPU solves many of those problems. Recently the [ModBot] channel on YouTube got sent a spool of the filament for testing.

The BIQU MorPhlex TPU filament being turned into squishy slippers. (Credit: ModBot, YouTube)

The ‘magic’ here is that this TPU claims to be a 90A TPU grade while on the spool, but after printing it becomes 75A, meaning a lot softer and squishier. Perhaps unsurprisingly, a big selling point on their product page is that you can print squishy shoes with it. Beyond this is claims to be compatible with ‘most FDM printers’, and the listed printing parameters are typical for TPU in terms of extruder and bed temperature.

After drying the filament as recommended for TPU in general, test prints were printed on a Bambu Lab H2D. Here BIQU recommends not using the AMS, but rather the dedicated TPU feeding channel. For the test prints some slippers were printed over the course of two days. In hindsight glue stick should have been applied to make parts removal easier.

The slippers were indeed squishy, but the real test came in the form of a Shore A hardness meter and some test cube prints. This showed an 80 – 85A for the BIQU MorPhlex test cube depending on whether to test the side or top. As the product datasheet indicates a final hardness of 75A +/- 3A, one could argue that it’s kind-of in spec, but it mostly raises questions on how parameters like temperature and extrusion speed affect the final result.

Josef Prusa Warns Open Hardware 3D Printing Is Dead

August 13, 2025 by Ian Bos 140 Comments

It’s hard to overstate the impact desktop 3D printing has had on the making and hacking scene. It drastically lowered the barrier for many to create their own projects, and much of the prototyping and distribution of parts and tools that we see today simply wouldn’t be possible via traditional means.

What might not be obvious to those new to the game is that much of what we take for granted today in the 3D printing world has its origins in open source hardware (OSHW). Unfortunately, [Josef Prusa] has reason to believe that this aspect of desktop 3D printing is dead.

If you’ve been following 3D printing for awhile, you’ll know how quickly the industry and the hobby have evolved. Just a few years ago, the choice was between spending the better part of $1,000 USD on a printer with all the bells and whistles, or taking your chances with a stripped-down clone for half the price. But today, you can get a machine capable of self calibration and multi-color prints for what used to be entry-level prices. According to [Josef] however, there’s a hidden cost to consider.

Continue reading “Josef Prusa Warns Open Hardware 3D Printing Is Dead” →