3D Print ABS Without A Screaming Hot Bed

ABS is a durable material that can be 3D printed, but requires a 100° C build surface. The print bed of [Pat]’s Bambu Lab A1 Mini is unable to get that hot, which means he can not print ABS…or can he? By fiddling a few settings, he prints ABS no problem with only a 60° C bed, thanks to a PLA interface layer.

Here’s what’s going on: first [Pat] prints a single layer of PLA, then does a filament swap for ABS (which the printer thinks is PETG with extrusion temperature bumped to 255° C and a tweaked flow rate) and lets the print finish. The end result is an ABS part with a single layer of PLA at the bottom, all printed on a 60° C bed. That PLA layer peels off easily, leaving a nice finish behind.

[Pat] is printing small parts in ABS for a custom skeletal mouse shell (pictured above) and his results are fantastic. We’re curious how this technique would fare with larger ABS objects, which tend to have more issues with warping and shrinkage. But it seems that at least for small parts, it’s a reliable and clever way to go.

We originally saw how [JanTec Engineering] used this technique to get less warping with ABS. As for why PLA is the way to go for the interface layer, we’ve learned that PLA only really truly sticks to PLA, making it a great interface or support for other filaments in general. (PETG on the other hand wants to stick to everything but PLA.)

Tool Turns SVGs Into Multicolor 3D Prints

Want to turn a scaled vector graphic into a multicolor 3D print, like a sign? You’ll want to check out [erkannt]’s svg2solid, a web-based tool that reads an SVG and breaks the shapes up by color into individual STL files. Drag those into your slicer (treating them as a single object with multiple parts) and you’re off to the races.

This sign was printed face-down on a textured build plate. The colors only need to be a few layers deep.

This is especially handy for making 3D printed versions of things like signs, and shown here is an example of exactly that.

It’s true that most 3D printer software supports the .svg format natively nowadays, but that doesn’t mean a tool like this is obsolete. SVG is a 2D format with no depth information, so upon import the slicer assigns a arbitrary height to all imported elements and the user must make any desired adjustments manually. For example, a handy tip for making signs is to make the “background” as thick as desired but limit colored elements to just a few layers deep. Doing so minimizes filament switching while having no impact on final visual appearance.

Being able to drag SVGs directly into the slicer is very handy, but working with 3D models has a certain “what you see is what you get” element to it that can make experimentation or alternate applications a little easier. Since svg2solid turns an SVG into discrete 3D models (separated by color) and each with user-defined heights, if you find yourself needing that then this straightforward tool is worth having in your bookmarks. Or just go straight to the GitHub repository and grab your own copy.

On the other hand, if you prefer your 3D-printed signs to be lit up in a faux-neon style then here’s how to do that in no time at all. Maybe there’s a way to mix the two approaches? If you do, be sure to use our tips line to let us know!

You Can 3D Print These Assistive Typing Tools

Typing can be difficult to learn at the best of times. Until you get the muscle memory down, it can be quite challenging. However, if you’ve had one or more fingers amputated, it can be even more difficult. Just reaching the keys properly can be a challenge. To help in this regard, [Roei Weiman] built some assistive typing tools for those looking for a little aid at the keyboard.

The devices were built for [Yoni], who works in tech and has two amputated fingers. [Roei] worked on many revisions to create a viable brace and extension device that would help [Yoni] type with greater accuracy and speed.

While [Roei] designed the parts for SLS 3D printing, it’s not mandatory—these can easily be produced on an FDM printer, too. For SLS users, nylon is recommended, while FDM printers will probably find best results with PETG. It may also be desirable to perform a silicone casting to add a grippier surface to some of the parts, a process we’ve explored previously.

The great thing about 3D printing is that it enables just about anyone to have a go at producing their own simple assistive aids like these. Files are on Instructables for the curious. Video after the break.

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3D Printing Uranium-Carbide Structures For Nuclear Applications

Fabrication of uranium-based components via DLP. (Zanini et al., Advanced Functional Materials, 2024)
Fabrication of uranium-based components via DLP. (Zanini et al., Advanced Functional Materials, 2024)

Within the nuclear sciences, including fuel production and nuclear medicine (radiopharmaceuticals), often specific isotopes have to be produced as efficiently as possible, or allow for the formation of (gaseous) fission products and improved cooling without compromising the fuel. Here having the target material possess an optimized 3D shape to increase surface area and safely expel gases during nuclear fission can be hugely beneficial, but producing these shapes in an efficient way is complicated. Here using photopolymer-based stereolithography (SLA) as  recently demonstrated by [Alice Zanini] et al. with a research article in Advanced Functional Materials provides an interesting new method to accomplish these goals.

In what is essentially the same as what a hobbyist resin-based SLA printer does, the photopolymer here is composed of uranyl ions as the photoactive component along with carbon precursors, creating solid uranium dicarbide (UC2) structures upon exposure to UV light with subsequent sintering. Uranium-carbide is one of the alternatives being considered for today’s uranium ceramic fuels in fission reactors, with this method possibly providing a reasonable manufacturing method.

Uranium carbide is also used as one of the target materials in ISOL (isotope separation on-line) facilities like CERN’s ISOLDE, where having precise control over the molecular structure of the target could optimize isotope production. Ideally equivalent photocatalysts to uranyl can be found to create other optimized targets made of other isotopes as well, but as a demonstration of how SLA (DLP or otherwise) stands to transform the nuclear sciences and industries.

The frame of a delta 3D printer is shown. The toolhead of the 3D printer does not have a hotend installed, but instead has a frame with a circular hole in the middle.

A Toolchanging Delta 3D Printer

We’ve seen quite a few delta 3D printers, and a good number of toolchanging printers, but not many that combine both worlds. Fortunately, [Ben Wolpert]’s project fills that gap with a particularly elegant and precise delta toolchanger.

The hotend uses three steel spheres and triangular brackets to make a repeatable three-point contact with the toolhead frame, and three pairs of corresponding magnets hold it in place. The magnets aren’t in contact, and the three magnets on the toolhead are mounted in a rotating ring. A motorized pulley on the printer’s frame drives a cable which runs through a flexible guide and around the rotating ring.

The whole setup is very reminiscent of the Jubilee toolchanging system, except that in this case, the pulley rotates the ring of magnets rather than a mechanical lock. By rotating the ring of magnets about 60 degrees, the system can move the pairs of magnets far enough apart to remove the hotend without much force.

The rest of the toolchanging system is fairly straightforward: each tool’s parking area consists of two metal posts which slot through corresponding holes in the hotend’s frame, and the motherboard uses some RepRapFirmware macros to coordinate the tool changes. The only downside is that a cooling fan for the hotend still hadn’t been implemented, but a desk fan seemed to work well enough in [Ben]’s tests. The files for the necessary hardware and software customizations are all available on GitHub.

We’ve only seen a similar toolchanging system for a delta printer once before, but we have seen a great variety of toolchangers on the more common Cartesian systems. Don’t like the idea of changing extruders? We’ve also seen a multi-extruder printer that completely eliminates tool switching.

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Learn 15 Print-in-Place Mechanisms In 15 Minutes

3D printed in-place mechanisms and flexures, such as living hinges, are really neat when you can get them to print correctly. But how do you actually do that? YouTuber [Slant 3D] is here with a helpful video demonstrating the different kinds of springs and hinges (Video, embedded below) that can be printed reliably, and discusses some common pitfalls and areas to concentrate upon.

Living hinges are everywhere and have been used at least as long as humans have been around. The principle is simple enough; join two sections to move with a thinned section of material that, in small sections, is flexible enough to distort a few times without breaking off. The key section is “a few times”, as all materials will eventually fail due to overworking. However, if this thing is just a cheap plastic case around a low-cost product, that may not be a huge concern. The video shows a few ways to extend flexibility, such as spreading the bending load across multiple flexure elements to reduce the wear of individual parts, but that comes at the cost of compactness.

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Move Over, Lithophane: 3D Printed 3D Photos With Gaussian Splats

If you had asked us yesterday “How do you 3D Print a Photo”, we would have said “well, that’s easy, do a lithophane”– but artist, hacker and man with a very relaxing voice [Wyatt Roy] has a much more impressive answer: Gaussian splats, rendered in resin.

Gaussian splats are a 3D scanning technique aimed at replicating a visual rather than geometry, like the mesh-based 3D-scanning we usually see on Hackaday. Using photogrammetry, a point cloud is generated with an associated 3D Gaussian function describing the colour at that point. Blend these together, and you can get some very impressive photorealistic 3D environments. Of course, printing a Gaussian smear of colour isn’t trivial, which is where the hacking comes in.

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