Despite the best efforts of the RepRap community over the last twenty years, self-replicating 3D printers have remained a stubbornly elusive goal, largely due to the difficulty of printing electronics. [Brian Minnick]’s fully-printed 3D printer could eventually change that, and he’s already solved an impressive number of technical challenges in the process.

[Brian]’s first step was to make a 3D-printable motor. Instead of the more conventional stepper motors, he designed a fully 3D-printed 3-pole brushed motor. The motor coils are made from solder paste, which the printer applies using a custom syringe-based extruder. The paste is then sintered at a moderate temperature, resulting in traces with a resistivity as low as 0.001 Ω mm, low enough to make effective magnetic coils.

Brushed motors are less accurate than stepper motors, but they do have a particularly useful advantage here: their speed can be controlled simply by varying the voltage. This enables a purely electromechanical control system – no microcontroller on this printer! A 3D-printed data strip encodes instructions for the printer as holes in a plastic sheet, which open and close simple switches in the motor controller. These switches control the speed, direction, and duration of the motors’ movement, letting the data strip encode motion vectors.

Remarkably, the hotend on this printer is also 3D-printed. [Brian] took advantage of the fact that PEEK’s melting point increases by about 110 ℃ when it’s annealed, which should allow an annealed hotend to print itself. So far it’s only extruded PLA, but the idea seems sound.

The video below the break shows a single-axis proof of concept in action. We haven’t been able to find any documentation of a fully-functional 3D printer, but nevertheless, it’s an impressive demonstration. We’ve covered similar printers before, and if you make progress in this area, be sure to send us a tip.

youtube.com/embed/xiygZo0YxBw?…

hackaday.com/2025/04/20/the-mo…

Entry-level oscilloscopes are a great way to get some low-cost instrumentation on a test bench, whether it’s for a garage lab or a schoolroom. But the cheapest ones are often cheap for a reason, and even though they work well for the price they won’t stand up to more advanced equipment. But missing features don’t have to stay missing forever, as it’s possible to augment them to get some of these features. [Tommy’s] project shows you one way to make a silk purse from a sow’s ear, at least as it relates to oscilloscopes.

Most of the problem with these lower-cost tools is their low precision due to fewer bits of analog-digital conversion. They also tend to be quite noisy, further lowering the quality of the oscilloscope. [Tommy] is focusing his efforts on the DSO138-mini, an oscilloscope with a bandwidth of 100 kHz and an effective resolution of 10 bits. The first step is to add an anti-aliasing filter to the input, which is essentially a low-pass filter that removes high frequency components of the signal, which could cause a problem due to the lower resolution of the device. After that, digital post-processing is done on the output, which removes noise caused by the system’s power supply, among other things, and essentially acts as a second low-pass filter.

In part 2 of the project, [Tommy] demonstrates the effectiveness of these two methods with experimental data, showing that a good percentage of the noise on a test signal has been removed from the output. All the more impressive here is that the only additional cost besides the inexpensive oscilloscope itself is for a ceramic capacitor that costs around a dollar. We were also impressed: [Tommy] is a junior in high school!

Presumably, you could apply these techniques to other inexpensive equipment, like this even cheaper oscilloscope based on the ESP32.

hackaday.com/2025/04/20/low-co…

In this series of 23 YouTube videos [Rich] puts the AMD Zynq-7000 SoC through its paces by building a development board from the ground up to host it along with its peripherals. The Zynq is part FPGA and part CPU, and while it has been around for a while, we don’t see nearly as many projects about it as we’d like.

Rich covers everything from the power system to HDMI, USB, DDR RAM, and everything in between. By the end, he’s able to boot PetaLinux.

The Zynq SoC includes an ARM Cortex-A9 Based APU and an Artix-7 FPGA (or a Kintex-7 FPGA on higher models). In case you missed it, Xilinx was recently acquired by AMD, which is why you might have remembered this as a Xilinx part.

We’ve heard from [Rich] before. Back in 2021 we saw his Arduino Brings USB Mouse To Homebrew Computer. Don’t miss his follow-up playlist: Building on my Zynq-7000 in which he takes his Zynq-7000 board even further.

If you’re interested in FPGA technology but need something more easy going to get you started, be sure to check out how to build a 6809 CPU on an FPGA. Or, if you need something even simpler, report for boot camp.

youtube.com/embed/jbG5KUbGaGE?…

Thanks to [Alex] for the tip!

hackaday.com/2025/04/20/buildi…

E buona Pasqua, riempiamoci la bocca di Pace.

Gli Usa avvertono, 'senza una svolta su Kiev ci sfiliamo'

Fonte: ANSA
search.app/dRKGm

Parlando del padre:

"Ha preferito il lager piuttosto che arrendersi al nazifascismo e combattere con i tedeschi contro gli italiani" – ha spiegato – "aveva fatto amicizia con un compagno che gli aveva salvato la vita. Si chiamava Vasco"

agi.it/spettacolo/news/2025-04…

WASHINGTON (AP) — The State Department has shut down its office that sought to deal with misinformation and disinformation that Russia, China and Iran have been accused of spreading.

Secretary of State Marco Rubio said in a statement Wednesday that he had closed what had been known as the Global Engagement Center because it had taken actions to restrict freedom of speech in the United States and elsewhere.

The center has been a frequent target of criticism from conservatives for calling out media and online reports that it said are biased or untruthful. At times, it has identified U.S. websites and social media accounts that it argued were amplifying misinformation, particularly related to the Russia-Ukraine war.

“It is the responsibility of every government official to continuously work to preserve and protect the freedom for Americans to exercise their free speech,” Rubio said, charging that the office worked “to actively silence and censor the voices of Americans they were supposed to be serving.”

Rubio said that is “antithetical” to the principles that “we should be upholding.”

Congress had supported the center’s work, as had previous State Department leadership.

“This is a deeply misleading (and) unserious portrayal of an organization focused on identifying foreign — primarily Russian — disinformation ops,” former State Department spokesman Ned Price said in a post on X.

dicorinto.it/articoli/the-stat…

When we say non-planar slicing is for the birds, we mean [Joshua Bird], who demonstrates the versatility of his new non-planar S4-Slicer by printing a Benchy upside down with the “Core R-Theta” printer we have featured here before.
S4 slicer uses the path from any point (here, Benchy’s prow) as its basis…
This non-planar slicer is built into a Jupyter notebook, which follows a relatively simple algorithm to automatically generate non-planar toolpaths for any model. It does this by first generating a tetrahedral mesh of the model and then calculating the shortest possible path through the model from any given tetrahedron to the print bed. Even with non-planar printing, you need to print from the print-bed up (or out).

Quite a lot of math is done to use these paths to calculate a deformation mesh, and we’ll leave that to [Joshua] to explain in his video below. After applying the deformation, he slices the resulting mesh in Cura, before the G-code goes back to Jupyter to be re-transformed, restoring the shape of the original mesh.
… to generate deformed models for slicing, like this.
So yes, it is G-code bending as others have demonstrated before, but in a reproducible, streamlined, and straightforward workflow. Indeed, [Josh] credits much of the work to earlier work on the S^3-Slicer, which inspired much of the logic and the name behind his S4 slicer. (Not S4 as in “more than S^3” but S4 as a contraction of “Simplified S^3”). Once again, open source allows for incremental innovation.

It is admittedly a computationally intensive process, and [Joshua] uses a simplified model of Benchy for this demo. This seems exactly the sort of thing we’d like to burn compute power on, though.

This sort of non-planar 3D printing is an exciting frontier, one which we have covered before. We’ve seen techniques for non-planar infill, or even to print overhangs on unmodified Cartesian printers, but this is probably the first time we’ve seen Benchy given the non-planar treatment. You can try S4 slicer for yourself via GitHub, or just watch the non-planar magic in action after the break.

youtube.com/embed/M51bMMVWbC8?…

hackaday.com/2025/04/20/non-pl…

Nella loro eleganza, i mici sono diventati discreti guardiani del parco, custodi ideali di un passato che ancora parla.

agi.it/cronaca/news/2025-04-19…

#gatti

Riporto dalla newsletter di Haaretz:

The New York Times reported that the White House's antisemitism task force sent Harvard University its letter demanding reforms by mistake.

Ma perché l'estrema destra non riesce a non essere cialtrona? È una sua caratteristica genetica o hanno semplicemente la sfortuna di trovarsi leader cialtroni ad ogni latitudine?

A rendere la questione piuttosto complicata è il fatto che la terapia familiare è una pratica continuamente in cambiamento, la teoria sistemica applicata alla psicoterapia è da sempre costantemente in cerca di un modo per superarsi. Dalla sua alba questa pratica si è presentata come inquieta e instabile. Diversamente da quanto accade per altri approcci terapeutici, un sistemico che passasse qualche anno su un’isola deserta, al ritorno difficilmente troverebbe tutto come prima.
O almeno è stato così per una fetta importante della sua storia. Questo si deve, credo, a due ragioni soprattutto...

Dal mio blog di psicoterapia:
massimogiuliani.it/blog/2025/0…

Cosa si insegna e, soprattutto, cosa no (nuove note su integrazioni ed eclettismi) - Corpi che parlano, il blog

"La terapia familiare ha senza dubbio cambiato notevolmente le pratiche di salute mentale, ma in qualche modo ha perso per strada gran parte dell'antica eccitazione (...) Che ne è stato di quell'idea straordinariamente nuova, di quell'audace salto

^{massimo giuliani (Corpi che parlano, il blog)}