Full disclosure. If you want a lathe capable of turning metal stock, you probably should just buy one. But what fun is that? You can do like [kachurovskiy] and build one with your 3D printer. If you are chuckling, thinking you can’t make 3D printed parts sturdy enough, you aren’t exactly wrong. [Kachurovskiy’s] trick is to 3D print forms and then cast the solid parts in concrete. The result looks great, and we don’t doubt his claim that it “can surpass many comparable lathes in rigidity and features.”
Even he admits that this is a “… hard, long, and expensive project…” But all good projects are. There’s a GitHub page with more details and informative videos below. The action shots are in the last video just before the six-minute mark. Around the seven-minute mark, you can see the machine cut a conical thread. Color us impressed!
The header image above shows a completely unsupported 3D-printed bridge, believe it or not. You’re looking at the bottom of the print. [Make Wonderful Things] wondered whether unsightly unsupported bridges could be improved, and has been busy nailing down remarkably high-quality results by exhaustive testing of different settings.
It all started when they thought that unsupported bridges looked a lot as though they were made from ropes stretched between two points. Unlike normal layers, these stretched extrusions didn’t adhere to their neighbors. They are too far apart from one another, and there’s no “squish” to them. But could this be overcome?
His experiments centered mainly around bridge printing speed, temperature, and bridge flow. That last setting affects how much the extrusion from the hot end is adjusted when printing a bridge. He accidentally increased it past 1.0 and thought the results were interesting enough to follow up on; it seemed that a higher flow rate when printing a bridge gave the nudge that was needed to get better inter-line adhesion. What followed was a lot of testing, finally settling on something that provided markedly better results than the stock slicer settings. Markedly better on his test pieces, anyway.
The best results seem to come from tweaking the Bridge Flow rate high enough that extrusions attach to their neighbors, printing slowly (he used 10 mm/sec), and ensuring the bridged area is as consistent as possible. There are still open questions, like some residual sagging at corners he hasn’t been able to eliminate, but the results otherwise look great. And it doesn’t even require laying one’s printer on its side!
All the latest is on the project page where you can download his test models, so if you’re of a mind to give it a try be sure to check it out and share your results. Watch a short video demonstrating everything, embedded just under the page break.
3D printing has taken off into the hands of almost anyone with a knack for wanting something quick and easy. No more messing around with machining or complex assembly. However, with the general hands-off nature of most 3D prints, what could be possible with a little more intervention during the printing process? [Ben] from Designed to Make represents this perfectly with an entire centrifugal pump printed all at once.
This project may not entirely fit into the most strict sense of “print in place”; however, the entire pump is printed as one print file. The catch is the steps taken during printing, where a bearing is placed and a couple of filament changes are made to allow dissolvable supports to be printed. Once these supports are dissolved away, the body is coated with epoxy to prevent any leakage.
Testing done by [Ben] showed more than impressive numbers from the experimental device. Compared to previous designs made to test impeller features, the all in one pump could stand its own against in most categories.
One of the greatest parts of the open source 3D printing world is the absolute freedom and ingenuity that comes out of it, and this project is no exception. For more innovations, check out this DIY full color 3D printing!
When it comes to soldering on a PCB it almost always helps to have some way to hold the board off your workbench, allowing leads to pass though with out making it unstable and keeping it level while working with tiny components. This project sent in by [Mel] was born out of necessity he was going to be teaching a soldering class and needed a way to keep boards in place, and so designed this Print-in-place PCB holder.
While there are certainly a long list of products designed to serve this function [Mel] took advantage of some idle 3D printers to turn out PCB stands that require no assembly, just the addition of a rubber band and they are ready for use. Part of the challenge of print in place 3D prints is dialing in the tolerances of your design and printer, and for this [Mel] printed some smaller slider mechanisms that were quick to print and iterate with until he was happy and could start turning out the larger design using those values.
The full PCB holder includes 3 independent sliders allowing for boards of all shapes and sizes to be held. To tension the board mounts there is a slow lower down on the uprights to allow for a rubber band to be added pulling all three towards the center. Finally [Mel] included small trays between the 3 sliders to give you a convenient place to components are you assemble your board. The 3D print falls are all available for download and [Mel] also included the small slider as a 3D print for you to check your printer tollerances before you run off the final design. Thanks [Mel] for sending in your soldering tool design, it’s a great addition to some of our other soldering assistant devices we’ve featured.
[Prusa] have a number of announcements, and one of the more unusual ones is that liquid printing is coming to the Prusa XL. Specifically, printing in real, heat-resistant silicone (not a silicone-like plastic) is made possible thanks to special filament and a special toolhead. It’s the result of a partnership with Filament2, and the same process could even be used to print with other liquids, including chocolate.
Look closely and you will see the detail in the nozzle, which mixes the two-part formula.
The process is as unusual as it is clever. The silicone is a two-part formula, but there is no reservoir or pump involved. Instead, there are two filaments, A and B. When mixed, they cure into solid silicone.
What is unusual is that these filaments have a liquid core. Upon entering the extruder, the outer sheath is cut away, and the inner liquid feeds into a mini mixing nozzle. The nozzle deposits the mixed silicone onto the print, where it cures. It isn’t clear from the demo where the stripped outer casing goes, but we assume it must get discarded or is possibly stowed temporarily until it can be removed.
Liquid-core filament is something we certainly didn’t have on our bingo card, but we can see how it makes sense. A filament format means the material can be handled, fed, and deposited precisely, benefiting from all of the usual things a filament-based printer is good at doing.
What’s also interesting is that the liquid toolhead can co-exist with other toolheads on the XL; in fact, they make a point of being able to extrude silicone as well as the usual thermoplastics into the same print. That’s certainly a trick no one else has been able to pull off.
There are a few other announcements as well, including a larger version of their Core One printer and an open-source smart spool standard called OpenPrintTag, a reusable and reprogrammable NFC insert for filament spools that gives you all of the convenience of automating color and material reading without the subtle (or overt) vendor lock-in that comes with it.
Watch a demo of the new silicone extruder in the video, embedded just under the page break. The new toolhead will be 1,009 USD when it launches in early 2026.
Wouldn’t it be nice to 3D print an entire custom tire for small robots? It sure would, so [Angus] of [Maker’s Muse] decided to investigate whether nifty new filaments like expanding TPU offer anything new in this area. He did more than just print out a variety of smooth tires; he tested each with a motorized platform attached to a load cell, driving on a dusty sheet of MDF to simulate the average shop floor, or ant weight combat robot arena.
Why bother making your own wheels? As [Angus] points out, when one is designing their own robots from scratch, it’s actually quite difficult to find something off the shelf that is just the right size. And even if one does find a wheel that is just right, there’s still the matter of fitting it to the shaft. Things would be so much easier if one could simply 3D print both wheel and tire in a material that performs well.
Like TPU, but squishier.
Here’s what he found: Siraya Tech’s TPU air filament (about 70A on the Shore hardness scale) performed the best. This is TPU plus a heat-activated additive that foams up during extrusion, resulting in a flexible print that looks and feels more like foam than usual TPU. It makes a promising tire that performs as well as it looks. Another expanding filament, PEBA air (also from Siraya Tech) didn’t look or perform as well, but was roughly in the same ballpark.
Both performed better than the classic DIY options of 3D-printed plain TPU, or laser-cut EVA foam. It’s certainly a lot less work than casting custom tires.
What about adding a tread pattern? [Angus] gave it a try. Perhaps unsurprisingly, a knobby tire has worse traction compared to a smooth tire on smooth MDF. But sometimes treads are appropriate, and as [Angus] points out, if one is 3D printing tires then adding treads comes at essentially zero cost. That’s a powerful ability.
Even if you are not interested in custom wheels, that foaming TPU filament looks pretty nifty. See for yourself in the video, embedded just below. If you find yourself finding a good use for it, be sure to drop us a tip!
We’ve often thought that 3D printers make excellent school projects. No matter what a student’s interests are: art, software, electronics, robotics, chemistry, or physics, there’s something for everyone. A recent blog post from [Prusa Research] shows how Johannes Kepler University is using 3D printing to teach math. You can see a video with Professor [Zsolt Lavicza] explaining their vision below.
Instead of relying on abstract 3D shapes projected on a 2D screen, GeoGebra, educational math software, creates shapes that you can produce on a 3D printer. Students can physically handle and observe these shapes in the real world instead of on a flat screen.
One example of how the 3D printer finds use in a math class is producing “Genius Square,” a multilevel tic-tac-toe game. You can find the model for that and other designs used in the classes, on Printables. Some prints are like puzzles where students assemble shapes from pieces.
