Regretfully: $3,000 Worth Of Raspberry Pi Boards

We feel for [Jeff Geerling]. He spent a lot of effort building an AI cluster out of Raspberry PI boards and $3,000 later, he’s a bit regretful. As you can see in the video below, it is a neat build. As Jeff points out, it is relatively low power and dense. But dollar for dollar, it isn’t much of a supercomputer.

Of course, the most obvious thing is that there’s plenty of CPU, but no GPU. We can sympathize, too, with the fact that he had to strip it down twice and rebuild it for a total of three rebuilds. One time, he decided to homogenize the SSDs for each board. The second time was to affix the heatsinks. It is always something.

With ten “blades” — otherwise known as compute modules — the plucky little computer turned in about 325 gigaflops on tests. That sounds pretty good, but a Framework Desktop x4 manages 1,180 gigaflops. What’s more is that the Framework turned out cheaper per gigaflop, too. Each dollar bought about 110 megaflops for the Pis, but about 140 for the Framework.

Continue reading “Regretfully: $3,000 Worth Of Raspberry Pi Boards”

Fnirsi IPS3608: A Bench Power Supply With Serious Flaws

Fnirsi is one of those brands that seem to pop up more and more often, usually for portable oscilloscopes and kin. Their IPS3608 bench power supply is a bit of a departure from that, offering a mains-powered PSU that can deliver up to 36 VDC and 8 A in a fairly compact, metal enclosure. Recently [Joftec] purchased one of these units in order to review it and ended up finding a few worrying flaws in the process.

One of the claims made on the product page is that it is ‘much more intelligent than traditional power supplies’, which is quite something to start off with. The visual impression of this PSU is that it’s somewhat compromised already, with no earth point on the front next to the positive and negative banana plug points, along with a tilting screen that has trouble staying put. The USB-C and -A ports on the front support USB-PD 3.0 and a range of fast charge protocols

The ‘intelligence’ claim seems to come mostly from the rather extensive user interface, including a graphing function. Where things begin to fall apart is when the unit locks up during load testing presumably due to an overheating event. After hooking up an oscilloscope, the ripple at 1 VDC was determined to be about 200 mV peak-to-peak at 91 kHz. Ripple increased at higher voltages, belying the ’10 mV ultra-low ripple’ claim.

A quick teardown revealed the cause for the most egregious flaw of the unit struggling to maintain even 144 Watt output: a very undersized heatsink on the SMPS board. The retention issues with the tilting issue seemed to be due to a design choice that prevents the screen from rotating without breaking plastic. While this latter issue could be fixed, the buggy firmware and high ripple on the DC output make this €124 ‘285 Watt’ into a hard pass.

Continue reading “Fnirsi IPS3608: A Bench Power Supply With Serious Flaws”

Hackaday Podcast Episode 338: Smoothing 3D Prints, Reading CNC Joints, And Detecting Spicy Shrimp

This week, Hackaday’s Elliot Williams and Kristina Panos met up over the tubes to bring you the latest news, mystery sound, and of course, a big bunch of hacks from the previous seven days or so.

In Hackaday news, we’ve got a new contest running! Read all about the 2025 Component Abuse Challenge, sponsored by DigiKey, and check out the contest page for all the details. In sad news, American Science & Surplus are shuttering online sales, leaving just the brick and mortar stores in Wisconsin and Illinois.

On What’s That Sound, it’s a results show, which means Kristina gets to take a stab at it. She missed the mark, but that’s okay, because [Montana Mike] knew that it was the theme music for the show Beakman’s World, which was described by one contestant as “Bill Nye on crack”.

After that, it’s on to the hacks and such, beginning with a really cool way to smooth your 3D prints in situ. JWe take a much closer look at that talking robot’s typewriter-inspired mouth from about a month ago. Then we discuss several awesome technological feats such as running code on a PAX credit card payment machine, using the alphabet as joinery, and the invention of UTF-8 in general. Finally, we discuss the detection of spicy shrimp, and marvel at the history of email.

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

 

Download in DRM-free MP3 and savor at your leisure.

Continue reading “Hackaday Podcast Episode 338: Smoothing 3D Prints, Reading CNC Joints, And Detecting Spicy Shrimp”

Smooth! Non-Planar 3D Ironing

Is 2025 finally the year of non-planar 3D printing? Maybe it won’t have to be if [Ten Tech] gets his way!

Ironing is the act of going over the top surface of your print again with the nozzle, re-melting it flat. Usually, this is limited to working on boring horizontal surfaces, but no more! This post-processing script from [Tenger Technologies], coupled with a heated, ball-shaped attachment, lets you iron the top of arbitrary surfaces.

At first, [Ten Tech] tried out non-planar ironing with a normal nozzle. Indeed, we’ve seen exactly this approach taken last year.  But that approach fails at moderate angles because the edge on the nozzle digs in, and the surrounding hot-end parts drag.

[Ten Tech]’s special sauce is taking inspiration from the ball-end mill finishing step in subtractive CNC work: he affixed the round tip of a rivet on the end of a nozzle, and insulating that new tool turned it into an iron that could smooth arbitrary curvy top layers.

One post-processing script later, and the proof of concept is working. Check out the video below to see it in action. As it stands, this requires a toolhead swap and the calibration of a whole bunch of new parameters, but it’s a very promising new idea for the community to iterate on. We love the idea of a dedicated tool and post-processing smoother script working together in concert.

Will 2025 be the year of non-planar 3DP? We’ve seen not one but two superb multi-axis non-planar printer designs so far this year: one from [Joshua Bird] and the other from [Daniel] of [Fractal Robotics]. In both cases, they are not just new machines, but are also supported with novel open-source slicers to make them work. Now [Ten Tech]’s ironer throws its hat in the ring. What will we see next?

Thanks to [Gustav Persson] for the tip!

Continue reading “Smooth! Non-Planar 3D Ironing”

Off To The Races With ESP32 And EInk

Off to the races? Formula One races, that is. This project by [mazur8888] uses an ESP32 to keep track of the sport, and display a “live” dashboard on a 2.9″ tri-color LCD.

“Live” is in scare quotes because updates are fetched only every 30 minutes; letting the ESP32 sleep the rest of the time gives the tiny desk gadget a smaller energy footprint. Usually that’s to increase battery life, but this version of the project does not appear to be battery-powered. Here the data being fetched is about overall team rankings, upcoming races, and during a race the current occupant of the pole-position.

There’s more than just the eInk display running on the ESP32; as with many projects these days, micro-controller is being pressed into service as a web server to host a full dashboard that gives extra information as well as settings and OTA updates. The screen and dev board sit inside a conventional 3D-printed case.

Normally when talking Formula One, we’re looking into the hacks race teams make. This hack might not do anything revolutionary to track the racers, but it does show a nice use for a small e-ink module that isn’t another weather display. The project is open source under a GPL3.0 license with code and STLs available on GitHub.

Thanks to [mazur8888]. If you’ve got something on the go with an e-ink display (or anything else) send your electrophoretic hacks in to our tips line; we’d love to hear from you.

3D Modeling With Paper As An Alternative To 3D Printing

Manual arrangement of the parts in Pepakura Designer. (Credit: Arvin Podder)
Manual arrangement of the parts in Pepakura Designer. (Credit: Arvin Podder)

Although these days it would seem that everyone and their pets are running 3D printers to churn out all the models and gadgets that their hearts desire, a more traditional approach to creating physical 3D models is in the form of paper models. These use designs printed on paper sheets that are cut out and assembled using basic glue, but creating these designs is much easier these days, as [Arvin Poddar] demonstrates in a recent article.

The cool part about making these paper models is that you create them from any regular 3D mesh, with any STL or similar file from your favorite 3D printer model site like Printables or Thingiverse being fair game, though [Arvin] notes that reducing mesh faces can be trickier than modelling from scratch. In this case he created the SR-71 model from scratch in Blender, featuring 732 triangles. What the right number of faces is depends on the target paper type and your assembly skills.

Following mesh modelling step is mesh unfolding into a 2D shape, which is where you have a few software options, like the paid-for-but-full-featured Pepakura Designer demonstrated, as well as the ‘Paper Model’ exporter for Blender.

Beyond the software used to create the SR-71 model in the article, the only tools you really need are a color printer, paper, scissor,s and suitable glue. Of course you are always free to use fancier tools than these to print and cut, but the bar here is pretty low for the assembly. Although making functional parts isn’t the goal here, there is a lot to be said for paper models for pure display pieces and to get children interested in 3D modelling.

ESP32 Hosts Functional Minecraft Server

If you haven’t heard of Minecraft, well, we hope you enjoyed your rip-van-winkle nap this past decade or so. For everyone else, you probably at least know that this is a multiplayer, open world game, you may have heard that running a Minecraft server is a good job for maxing out a spare a Raspberry Pi. Which is why we’re hugely impressed that [PortalRunner] managed to squeeze an open world onto an ESP32-C3.

Of course, the trick here is that the MCU isn’t actually running the game — it’s running bareiron, [PortalRunner]’s own C-based Minecraft server implementation. Rewriting the server code in C allows it to be optimized for the ESP32’s hardware, but it also let [PortalRunner] strip his server down to the bare essentials, and tweak everything for performance. For example, instead of the multiple octaves of Perlin noise for terrain generation, with every chunk going into RAM, he’s using the x and z of the corners as seeds for the psudorandom rand() function, and interpolating between them. Instead of caves being generated by a separate algorithm, and stored in memory, in bareiron the underground is just a mirror-image of the world above. Biomes are just tiled, and sit separately from one another.

So yes, what you get from bareiron is simpler than a traditional Minecraft world — items are simplified, crafting is simplified, everything is simplified, but it’s also running on an ESP32, so you’ve got to give it a pass. With 200 ms to load each chunk, it’s playable, but the World’s Smallest Minecraft Server is a bit like a dancing bear: it’s not about how well it dances, but that it dances at all.

This isn’t the first time we’ve seen Minecraft’s server code re-written: some masochist did it in COBOL, but at least that ran on an actual computer, not a microcontroller. Speaking of low performance, you can’t play Minecraft on an SNES, but you can hide the game inside a cartridge, which is almost as good.

Thanks to [CodeAsm] for the tip. Please refer any other dancing bears spotted in the wild to our tips line.

Continue reading “ESP32 Hosts Functional Minecraft Server”