A white background is shown, with a grey metal plate at the base of the image. On the plate are three tiny green Benchy models. Above the Benchies is a glass cylinder. Below one of the Benchy models, text says "250 µm".

Printing Micron-Scale Benchies With Resin And Turmeric

Resin 3D printing has opened up a whole new scale of resolution for hackers, but the technology can go still finer; commercial micro-SLA and two-photon polymerization printers can print items with sub-micron feature sizes, but the machines are well out of reach for hackers. There’s more than one way to get such high resolution, though, as [Diffraction Limited] demonstrated with his micron-scale resin printer.

The printer builds on [Diffraction Limited]’s previous micro-manipulator and fiber-coupled laser. The micro-manipulator holds the end of the optical fiber just in front of the build plate, which is coated with resin. A 405-nm laser shines through the fiber, curing the resin in a narrow cone in front of the fiber’s core, which the micro-manipulator can trace in a pattern to build up objects, much like an FDM printer. Since the fiber’s inner core is only three microns across, the cured resin shears cleanly away from it when the fiber moves. Since the principle is so similar to an FDM printer, a standard slicer could be used to generate the tool paths.

Continue reading “Printing Micron-Scale Benchies With Resin And Turmeric”

Corners Lifting On 3D Prints? Guide Gives Prevention Tips

Large prints have a risk of warping, by which we mean corners can lift off the print bed as the object sort of curls inward on itself. It’s not always due to poor filament quality or an unclean build plate. Sound like something you’ve dealt with? Check out this handy roundup to understand why it happens, and learn ways to prevent it.

A big flat area with sharp corners is susceptible to warping. Breaking the footprint into a grid pattern helps distribute stresses instead of concentrating them at the corners.

The reason some objects have trouble while others don’t is physics. Deposited plastic shrinks ever so slightly as it cools, and some shapes — like wide, flat surfaces with sharp corners — are worse for this than others. This sort of problem is what the guide addresses with a number of techniques.

Some are simple, like turning on brims which increases an object’s footprint. This increased surface area offers more adhesion, but also increases heat transfer from the print bed into the model, slowing the cooling process. Thinner walls and an altered infill pattern is another option. Other techniques are more complex.

The most effective methods involve modifying the model itself to reduce or eliminate stress points. One such method is to break the model’s footprint into multiple zones with a shallow grid. Instead of one big flat bottom, the object has multiple smaller ones. Because big flat areas are more susceptible to warping than small ones, turning the bottom into a grid pattern helps spread those stresses out and prevent lifting.

If you design your own models, you’ll find several design tips worth keeping in mind. It’s always smart to practice good DFM (Design For Manufacturability) which means taking 3D printer strengths and weaknesses into account when designing an object. In this case, it can help prevent print failures. Good DFM can also make parts much, much stronger just by designing in the right features.

Art of 3D printer in the middle of printing a Hackaday Jolly Wrencher logo

Has FDM 3D Printing Hit Its Peak?

Over the time Hackaday has been in existence, the art of 3D printing has evolved from a relatively crude hit-and-miss affair to something approaching what we all imagined back then. You can’t yet walk up to a Star Trek replicator and ask for a part, but a modern state of the art consumer or prosumer grade printer will deliver consistent high-resolution parts, and in a surprisingly short time. [The Next Layer] asks whether consumer FDM printers have now reached the point at which they’re about as good as they’re going to get, and whether other technologies hold the future.

It’s a fair point to make that the resolution of a consumer FDM printer may be close to its mechanical limit. Techniques such as input shaping and the adoption of better CoreXY mechanisms mean that prints which once might have relied on SLA can be done in FDM. Healthy competition in the marketplace has delivered high quality colour printing, with tool-changing printers being no longer solely the preserve of the professional. He uses the example of a mobile phone to make the point that new machines have less of a wow factor to deliver, as increments have become less grand.

It’s a persuasive argument, and looking at the printers around us we can see it in action. The difference in ability between a 2020-ish and a 2026 FDM printer are far smaller than those between the same time periods in the last decade. Compare a MakerBot Cupcake and an Ultimaker II, or the Ultimaker and a Prusa Mini, and each is light years ahead of the last. But the best the Mini can do is surprisingly not as far behind as you’d expect to that of their latest, or of the equivalent from Bambu Labs.

Does this means that nothing new is coming in 3D printing? Of course not. UV printing is coming through and will deliver incredible results, as will SLS printing. It’s interesting he devotes little time to SLA printing, perhaps because it’s not as easy a process as FDM. He makes the point that we’ve never had it so good, as the high-end FDM features will appear in modestly priced machines, and we have those other technologies to look forward to.

It’s an interesting discussion, and you can see it below the break.

Continue reading “Has FDM 3D Printing Hit Its Peak?”

Laser Your Way To Smoother FDM 3D Prints

Now, not everyone minds the characteristic layer lines you get with Filament Deposition Modeling (FDM) 3D prints, but sometimes you need a smooth surface. If so we might go for filling primer, Bondo, or maybe break out the ABS and vapor smooth. Well, [I changed a thing] has an alternate suggestion: lasers. Laser melting can smooth the walls on a print, or the top surfaces as he shows in two different videos, both embedded below. The results look roughly similar to vapor smoothing, without the chemical exposure small risk of explosion.

Of course, you need a laser to do this, and [I changed a thing] has two diode lasers mounted to the X-axis of his printer. Of the two, the top surfaces were a lot easier to get right than the wall smoothing, which makes sense. Top surfaces are right there for the laser to get at, after all, while with his laser setup [I changed a thing] needs to get at the walls obliquely. [I changed a thing] tries melting layer-by-layer as well as a few methods to get at the walls of a finished print; which works best seems to depend on the size of and geometry of the object, so it looks like this technique is as much art as science right now.

This effort is closely related to the previous work [I changed a thing] did on improving layer adhesion with laser melting.  It’s also not the first time we’ve seen laser-driven print smoothing, but that project used non-planar movements to do a post-print laser pass.

Continue reading “Laser Your Way To Smoother FDM 3D Prints”

A clear tank of gel is shown against a black background. In the gel, the shape of a white plastic boat is suspended. A coarse-tipped needle dips into the top of the gel bath.

Support Bath Enables An Epoxy Benchy

There’s plenty of substances that can theoretically be extruded from a nozzle, but only a regrettably small subset of them can actually be used for 3D printing. One limiting factor is the liquid range: too high a melting point and it’s hard to reliably extrude, too low and it tends to ooze and flow once extruded. Embedded 3D printing offers a way around this: it submerges the entire print in a shear-thinning support gel which keeps liquids in place until they solidify. [Riley] of Riley’s Lab recently built such a 3D printer and used it to print in silicone and epoxy.

In place of the extruder, [Riley] mounted a mostly 3D printed syringe pump, which allowed him to squirt out almost any liquid. For a test, he printed a tardigrade model out of cream cheese. This was a good test material for several reasons: it’s cheap, easy to extrude, and holds it shape well after extrusion. Silicone and epoxy, however, won’t hold their shape, which is where the support bath comes it. This was a mixture of mineral and vegetable oil, with some fumed silica added to make it thick yet shear-thinning. This lets it contain the extruded liquid, yet flow as the extrusion needle slices through it.

For the first test, [Riley] printed a Benchy out of Sylgard 184. The outcome looked good in the bath, bar some stringing, but it seemed to have limited adhesion between layers, and disintegrated upon removal from the bath. A second test with a two-part epoxy worked much better; it also had some stringing, but it held together while the bath was washed away in isopropyl alcohol, and even seemed decently shock-resistant afterwards.

It’s great to see a hacker working on this technology; we’ve previously covered a commercial take on it, as well as some of the research that led to it.

Continue reading “Support Bath Enables An Epoxy Benchy”

3D-Printed Skin Gives Robots The Sensation Of Touch

Schematic diagram of the touch-sensitive skin. (Credit: Haofeng Chen et al., ArXiv, 2026)
Schematic diagram of the touch-sensitive skin. (Credit: Haofeng Chen et al., ArXiv, 2026)

Hypoesthesia, more commonly referred to as numbness, is one of the more distressing ailments that can affect us humans, primarily because it reminds us of just how much we rely on our sensation of touch in daily life. From experiencing the world around us, handling objects, noticing when you just bumped into that side table again and the comforting hug of a fellow human being, touch is perhaps the most important of our senses.

In that regard the recently published research by [Haofeng Chen] et al. on giving robots a skin that can experience touch seems rather important as it would give especially humanoid robots a more natural way to interact with their environment, using feedback from touch. Continue reading “3D-Printed Skin Gives Robots The Sensation Of Touch”

3D Printing A Railway Pump Car

It's arguably adult-sized. (Credit: Sam Barker, YouTube)
It’s arguably adult-sized. (Credit: Sam Barker, YouTube)

A staple of old movies featuring railways, many handcars – also called pump trolleys or pump cars – feature the characteristic seesawing beam. Requiring at least two people, the motion of this beam is subsequently converted into the rotating motion of the wheels, propelling it at a leisurely pace across the tracks. As a fun and yet functional mechanical contraption it also makes for an entertaining 3D printable project, which is what [Sam Barker] and [Tom] did.

You can find the entire project over at Printables if you are feeling the itch as well, though as of writing details on the required bolts and shafts are still pending.

Since the entire assembly had to be lugged over to the Open Sauce event in the US, they had to design it to be small enough to fit into check-in luggage and easy enough to reassemble in a hotel room. Naturally this put some constraints on the full size of the contraption, with it omitting compatibility with standard gauge railways and also being decidedly fun-sized.

That said, it seems to have left an impression on the folk over at Open Sauce, and it’s hard to argue with the sheer fun factor of such a co-op mode of transportation. Even if bicycle-style handcars are more popular these days, especially for tourist purposes, the old seesaw-style has that certain charm to it.

Continue reading “3D Printing A Railway Pump Car”