Printing With PHA Filament As Potential Alternative To PLA

December 14, 2025 by Maya Posch 29 Comments

PLA (polylactic acid) has become the lowest common denominator in FDM 3D printing, offering decent performance while being not very demanding on the printer. That said, it’s often noted that the supposed biodegradability of PLA turned out to be somewhat dishonest, as it requires an industrial composting setup to break it down. Meanwhile, a potential alternative has been waiting in the wings for a while, in the form of PHA. Recently, [JanTec Engineering] took a shot at this filament type to see how it prints and tests its basic resistance to various forms of abuse.

PHA (polyhydroxyalkanoates) are polyesters that are produced by microorganisms, often through bacterial fermentation. Among their advantages are biodegradability without requiring hydrolysis as the first step, as well as UV-stability. There are also PLA-PHA blends that exhibit higher toughness, among other improvements, such as greater thermal stability. So far, PHA seems to have found many uses in medicine, especially for surgical applications where it’s helpful to have a support that dissolves over time.

As can be seen in the video, PHA by itself isn’t a slam-dunk replacement for PLA, if only due to the price. Finding a PHA preset in slicers is, at least today, uncommon. A comment by the CTO of EcoGenesis on the video further points out that PHA has a post-printing ‘curing time’, so that mechanical tests directly after printing aren’t quite representative. Either you can let the PHA fully crystallize by letting the part sit for ~48 hours, or you can speed up the process by putting it in an oven at 70 – 80°C for 6-8 hours.

Overall, it would seem that if your goal is to have truly biodegradable parts, PHA is hard to beat. Hopefully, once manufacturing capacity increases, prices will also come down. Looking for strange and wonderful printing filament? Here you go.

Continue reading “Printing With PHA Filament As Potential Alternative To PLA” →

3D Printering: That New Color Printer

December 3, 2025 by Al Williams 15 Comments

Color 3D printing has gone mainstream, and we expect more than one hacker will be unpacking one over the holidays. If you have, say, a color inkjet printer, the process is simple: print. Sure, maybe make sure you tick the “color” box, but that’s about it. However, 3D printers are a bit more complicated.

There are two basic phases to printing color 3D prints. First, you have to find or make a model that has different colors. Even if you don’t make your own models (although you should), you can still color prints in your slicer.

The second task is to set the printer up to deal with those multiple colors. There are several different ways to do this, and each one has its pros and cons. Of course, some of this depends on your slicer, and some depends on your printer. For the purposes of this post, I’ll assume you are using a Slic3r fork like Prusa or OrcaSlicer. Most of the lower-priced printers these days work in roughly the same way. Continue reading “3D Printering: That New Color Printer” →

Necroprinting Isn’t As Bad As It Sounds

December 1, 2025 by Lewin Day 18 Comments

A mosquito has a very finely tuned proboscis that is excellent at slipping through your skin to suck out the blood beneath. Researchers at McGill University recently figured that the same biological structure could also prove useful in another was—as a fine and precise nozzle for 3D printing (via Tom’s Hardware).

Small prints made with the mosquito proboscis nozzle. Credit: research paper

To achieve this feat, the research team harvested the proboscis from a female mosquito, as only the female of the species sucks blood in this timeline. The mosquito’s proboscis was chosen over other similar biological structures, like insect stingers and snake fangs. It was prized for its tiny size, with an inside diameter of just 20 micrometers—which outdoes just about any man-made nozzle out there. It’s also surprisingly strong, able to resist up to 60 kPa of pressure from the fluid squirted through it.

Of course, you can’t just grab a mosquito and stick it on your 3D printer. It takes very fine work to remove the proboscis and turn it into a functional nozzle; it also requires the use of 3D printed scaffolding to give the structure additional strength. The nozzle is apparently used with bio-inks, rather than molten plastic, and proved capable of printing some basic 3D structures in testing.

Amusingly, the process has been termed 3D necroprinting, we suspect both because it uses a dead organism and because it sounds cool on the Internet. We’ve created a necroprinting tag, just in case, but we’re not holding our breath for this to become the next big thing. At 20 um, more likely the next small thing.

Further details are available in the research paper. We’ve actually featured quite a few mosquito hacks over the years. Video after the break.

Continue reading “Necroprinting Isn’t As Bad As It Sounds” →

How To Design 3D Printed Pins That Won’t Break

December 1, 2025 by Donald Papp 9 Comments

[Slant 3D] has a useful video explaining some thoughtful CAD techniques for designing 3D printed pins that don’t break and the concepts can be extended to similar features.

Sure, one can make pins stronger simply by upping infill density or increasing the number of perimeters, but those depend on having access to the slicer settings. If someone else is printing a part, that part’s designer has no actual control over these things. So how can one ensure sturdier pins without relying on specific print settings? [Slant 3D] covers two approaches.

The first approach includes making a pin thick, making it short (less leverage for stress), and adding a fillet to the sharp corner where the pin meets the rest of the part. Why? Because a rounded corner spreads stress out, compared to a sharp corner.

Continue reading “How To Design 3D Printed Pins That Won’t Break” →

On The Benefits Of Filling 3D Prints With Spray Foam

November 29, 2025 by Maya Posch 41 Comments

Closed-cell self-expanding foam (spray foam) is an amazing material that sees common use in construction. But one application that we hadn’t heard of before was using it to fill the internal voids of 3D printed objects. As argued by [Alex] in a half-baked-research YouTube video, this foam could be very helpful with making sure that printed boats keep floating and water stays out of sensitive electronic bits.

It’s pretty common knowledge by now that 3D printed objects from FDM printers aren’t really watertight. Due to the way that these printers work, there’s plenty of opportunity for small gaps and voids between layers to permit moisture to seep through. This is where the use of this self-expanding foam comes into play, as it’s guaranteed to be watertight. In addition, [Alex] also tests how this affects the strength of the print and using its insulating properties.

The test prints are designed with the requisite port through which the spray foam is injected as well as pressure relief holes. After a 24 hour curing period the excess foam is trimmed. Early testing showed that in order for the foam to cure well inside the part, it needed to be first flushed with water to provide the moisture necessary for the chemical reaction. It’s also essential to have sufficient pressure relief holes, especially for the larger parts, as the expanding foam can cause structural failure.

As for the results, in terms of waterproofing there was some water absorption, likely in the PETG part. But after 28 hours of submerging none of the sample cubes filled up with water. The samples did not get any stronger tensile-wise, but the compression test showed a 25 – 70% increase in resistance to buckling, which is quite significant.

Finally, after tossing some ice cubes into a plain FDM printed box and one filled with foam, it took less than six hours for the ice to melt, compared to the spray foam insulated box which took just under eight hours.

This seems to suggest that adding some of this self-expanding foam to your 3D printed part makes a lot of sense if you want to keep water out, add more compressive strength, or would like to add thermal insulation beyond what FDM infill patterns can provide.

Continue reading “On The Benefits Of Filling 3D Prints With Spray Foam” →

How To Print PETG As Transparently As Possible

November 29, 2025 by Lewin Day 6 Comments

PETG filament can be had in a variety of colors, just like any other. You can even get translucent or transparent forms if you want to print something vaguely see-through. But if you’re looking for a bit more visually impressive, you might like to pick up a few tips from [Tej Grewal] on making sure your prints come out as clear as possible.

Standard print settings aren’t great for transparency.

It all comes down to pathing of the 3D printer’s hot end. If it’s zigzagging back and forth, laying down hot plastic in all different orientations from layer to layer, you’re going to get a hazy, ugly, result that probably doesn’t look very see-through at all.

However, you can work around this by choosing slicer settings that make the tool pathing more suitable for producing a clearer part. [Tej] recommends going slow — as little as 20 mm/s during printing. He also states that removing top and bottom shells and setting wall loops to 1 can help to produce a part that’s entirely infill. Then, you’ll want to set infill to 100% and the direction to 0 or 90 degrees. This will ensure your hot end is just making long, straight strokes for layer after layer that will best allow light to pass through. You’ll also want to maximize nozzle flow to avoid any unsightly gaps or bubbles in your print.

[Tej] demonstrates the technique by creating a cover for a display. By using the settings in question, he creates a far more transparent plate, compared to the original part that has an ugly zig-zagging haze effect. You’re not going to get something optically clear this way; the final results are more lightly frosted, but still good.

Transparency will never be something 3D printers are great at. However, we have seen some interesting post-processing techniques that will blow your mind in this regard.

Designing PLA To Hold Over A Metric Ton

November 27, 2025 by Ian Bos 13 Comments

There’s never been such a thing as being “too competitive” when it comes to competition. This is something that [Tom Stanton] from “Tim Station”, [Tom]’s 2nd channel, took to heart for Polymaker’s 3D design challenge. The goal was simple: a single 3D printed part to hold as much weight as possible.

While seemingly simple, when considering the requirements, including a single print in addition to being able to open up for the mounts, the challenge gets exponentially more complicated. While the simplest and strongest joint would be a simple oval for uniform stress, this isn’t possible when considering the opening requirements. This creates a need for slightly more creativity.

[Tom] starts out with two flat C-shaped geometries to test his design. The design includes teeth specially placed to allow the forces to increase their own strength as force is applied. Flat features have the unfortunate quality of being able to slide across each other rather easily, which was the case during testing; however, the actual structures held up rather well. Moving onto the final design, including a hollow cavity and a much thicker depth, showed good promise early on in the competition, leading up to the finals. In fact, the design won out over anything else, getting over double the max strength of the runner up. Over an entire metric ton, the piece of plastic proved its abilities far past anything us here at Hackaday would expect from a small piece of PLA.

Design can be an absolute rabbit hole when it comes to even the simplest of things, as shown with this competition. [Tom] clearly showed some personal passion for this project; however, if you haven’t had the chance to dive this deep into CADing, keep sure to try out something like TinkerCAD to get your feet wet. TinkerCAD started out simple as can be but has exploded into quite the formidable suite!

Continue reading “Designing PLA To Hold Over A Metric Ton” →