Behold A 60 Hz Refresh Rate E-ink Monitor

June 13, 2026 by Donald Papp 51 Comments

E-ink displays have a number of advantages over other display types, but their refresh rate isn’t one of them. But what exactly makes them slow? According to [Wenting Zhang], it’s not an inherent limitation of the technology. It’s mainly the controller, and this limitation can be overcome to create a high-resolution 60 Hz refresh rate E-ink display, totally suitable for use as a computer monitor.

The reason E-ink displays are so slow is simple. For a long time, they existed for only one purpose: to be screens for e-readers. They had to work on devices that were generally low power, with limited interfaces and slow processors. Accommodating these factors was the primary driver behind the high latency and slow refresh rates associated with these displays.

It was actually the limited interface options rather than the slow refresh that initially led to a custom controller, because [Wenting] wanted to use an E-ink display on a laptop build. But it quickly became apparent that a custom controller could do considerably more than E-ink was known for.

Initial tests with fast refresh rates were so positive that it led to a Hackaday Supercon 2024 talk on how to make E-ink go fast, and more recently has culminated in the Modos Flow, a fully open-source, user-repairable 13.3″ portable E-ink monitor.

The development path from proof of concept to finished product has been a long one for [Wenting]. Not only did a lot of optimization and feature work need to be crafted from scratch in order to effectively balance appearance with responsiveness in different display modes, but the usual hassles of development and bad timing were also in full force. On top of it were wasteful vendor shenanigans, as well.

Check out the story in the video, embedded just below. If you’d like to buy one, there are monochrome and color versions offered through Crowd Supply.

Continue reading “Behold A 60 Hz Refresh Rate E-ink Monitor” →

Adding Weight To A 3D Print With Plaster Of Paris, Cleanly

June 12, 2026 by Donald Papp 15 Comments

Sometimes it’s useful to add extra mass to a 3D print, and [Joe Fedewa] shared a simple and effective technique that uses plaster of Paris. Rather than pause the print and insert hardware or weighted bits inside, he designed the base as hollow. Not in the sense of zero infill, but in the sense of modeling a cavity into the open bottom of the object.

An open cavity in the base is perfect for filling with plaster of Paris.

After the print is complete, he mixes the dry plaster with water until it creates a thick but pourable mixture. Then the object gets turned upside-down and the cavity filled. In about an hour, it will have set up enough to be handled and worked.

Plaster of Paris has a good heft to it, but more importantly it can be made perfectly presentable thanks to being very friendly to post-processing. Any rough spots can be easily sanded and the whole bottom smoothed, so one doesn’t even need to cap it off. Completely cured plaster can be sealed with a clear coat for a more durable finish, if desired.

This basic concept has been used in other ways, such as reinforcing prints with concrete to yield parts solid enough to make tools out of. But using plaster of Paris not just to add mass, but specifically to create a presentable surface that doesn’t need covering up is a neat and highly economical adaptation of the idea.

Other methods of adding mass to a 3D print include inserting metal balls or chunky nuts, bolts, or other hardware, but this method doesn’t require pausing prints to insert things. Nor does it require sealing off or capping the print, messing with goopy epoxies or resins, or spending a lot of money — making it a good one to keep in mind in case it comes in handy someday.

Glue-in Hinge Design Tries Something Different

June 12, 2026 by Donald Papp 17 Comments

Need a hinge in your 3D printed design and would prefer not to re-invent the wheel? You may find [Alex Krush]’s glue-in filament hinge useful.

This design (shown in this simple box as an example) makes a very close-fitting hinge point.

This design prints half the hinge as a separate piece — the u-shaped one in the picture to the side — that must be glued into the target object after printing. It’s a bit of extra work, but doing it this way has a couple advantages.

One is that printing some of the hinge elements separately means one no longer needs to choose between a print orientation that best suits the object, and a print orientation that works best for the hinge. Also, the length of 1.75 mm filament used as a hinge pin is held captive after assembly so there’s no need to glue the hinge pin itself.

[Alex] helpfully provides the parts in STEP format, which makes CAD tweaks and adjustments easy. While incorporating the design should be doable even if one is just using .stl or .3mf files because boolean subtraction and merging is all that’s needed, having the model in STEP format is so much better.

Should you need some pointers on incorporating either into FreeCAD, we have you covered.

Using A Mirror To 3D Scan Both Sides Of An Object At Once

June 2, 2026 by Donald Papp 28 Comments

Photogrammetry is the process of 3D scanning an object by taking a lot of photographs, then using software to turn those into a 3D model. But the process can only scan what the camera can see, and one can’t always get a good view of every part of an object. To solve this, [Thomas Megel] shared an experiment in using a mirror to capture the underside of an object simultaneously with its top. The results were encouraging!

Using a mirror as the turntable allows the camera to image the underside at the same time.

To do this he perched a small tabletop gaming mini on a mirror serving as a turntable platform in his self-designed OpenScan Mini machine, which is designed to take highly structured photos of small objects for scanning purposes. This produced a single scan with two objects, the original and its mirror image, together in one file.

Aligning separate models and combining them into one is a common way to deal with partial or incomplete scans. The idea here is to get two scans at once, instead of separately with a reposition of the object in between. Additionally, it should be possible for the software to automatically separate, align, and combine the two since it is known exactly where the mirror plane is.

As far as a proof of concept, it’s encouraging. [Thomas] is still playing with the idea and looking for suggestions, so if you have any insights be sure to share them.

3D scanning can be a very useful tool, and while photogrammetry can be done with little more than your mobile phone’s camera, in some ways the concept is over a hundred years old.

Bilingual E-paper News Feed Helps Brush Up Language Skills

June 1, 2026 by Donald Papp 3 Comments

[Bob] recently completed LanguageLearner, a desktop device that increases his exposure to a second language by offering up bite-sized news items in Italian, with a complementary English translation. Even better, it’s a project made almost entirely from inexpensive parts he had on hand; it consists of little more than a Raspberry Pi Pico W, a 4.2″ E-paper display, and a 3D-printed stand.

Here’s how it works: once every few hours, the system wakes up and uses its WiFi connection to fetch news from an Italian RSS feed. Having chosen a slice of current events, it translates to English with an API call then displays both versions on the display: original Italian up top, translated English below.

Consisting of little more than a Raspberry Pi Pico W, an E-paper display, and a 3D-printed stand, it’s a great use of spare parts.

E-paper is ideal for a semi-passive project like this because once data is written to the display, there it remains without needing power or upkeep of any kind. Perfect for a device that only wakes up every few hours for an update before going right back to sleep.

Due to the limited RAM of the Raspberry Pi Pico [Bob] has to be purposeful about fetching data, so he relies on text from a simple RSS feed to avoid running out of memory while making web requests. The other minor quibble is that the driver for the display only handles plain ASCII; characters that cannot be rendered are displayed as grey boxes, which you can see in the image up top. Still, it gets the job done.

Increasing exposure to a language one is learning is beneficial, and people like to experiment. From trying to optimize human wait times by inserting language micro-lessons to a calculator that works in Toki Pona, technology offers new ways for folks to experiment with how we learn and play with language.

Like A Wire Bender, But For Pop Tubes

June 1, 2026 by Donald Papp 13 Comments

Are you familiar with pop tubes? Resembling the corrugated section of a bendy straw, they are at the core of PopTuber, an intriguing research project from the Actuated Experience Lab at the University of Chicago.

With five motors and specialized gears a pop tube can be formed into complex, arbitrary shapes, and just as easily reset.

PopTuber shows how five motors and some specialized gears are all it takes to bend pop tubes into complex and stable 3D shapes. One can design the shapes in software, feed a pop tube into the shaper, and watch the device do the work. Importantly, the device can just as easily reset and re-use the tube. Watch the video (embedded below the page break) to see it in action and get a feel for what it can do.

In concept, it’s a little like a wire-bending machine, although wire benders are bulkier in comparison, more complex to scale, and unbending a wire is a separate process with its own hardware.

This project explores possibilities for a machine that can crank out complex curves on demand, such as oddball user interfaces, physical prototyping, and even a strange sort of physical display. But the real forward-thinking and interesting question researchers asked is whether this idea could be a form of programmable matter. The project shows that five actuators in a relatively compact package are all that’s needed to shape (and reset) a pop tube of arbitrary length in a programmable way, and it can scale easily to different sizes.

Continue reading “Like A Wire Bender, But For Pop Tubes” →

4-bit Relay Logic Counter Begs To Have Its Buttons Pushed

May 31, 2026 by Donald Papp 5 Comments

What’s one to do with some nice little relays of questionable pinout, and prototyping board? How about a quietly clicky 4-bit counter using relay logic with tons of buttons?

The register with LEDs and buttons is on the top board, the incrementer on the bottom board.

[Agatha Mallett] made the counter after finding herself in possession of a quantity of relays burdened by terrible documentation (the datasheet shockingly lacks a pinout, and doesn’t even mention the coil being unidirectional). But since the relays are also small and of decent quality, they were a good candidate for a small relay logic-based project.

The key to the build is implementing D-type flip-flops using relays. This is done by holding the coil voltage of each relay between its set and release voltage levels. A small voltage bump will energize the coil, closing the relay and leaving it closed. Conversely, a small negative spike releases the coil, leaving it open. This forms the basis of the counter, and [Agatha] has a separate write-up all about the details of using relays in this way.

Implementing this was rather less straightforward than it may sound because it relies on balancing the coils of many relays on a figurative knife-edge of voltage, but not every component is perfectly identical. A tweaked resistor or capacitor here and there was needed before things settled into reliability.

The end product has indicator LEDs, buttons to increment or clear the current count, and it even has buttons to set or clear individual bits. This is a project that begs to be interacted with, and there’s a short video on the project page so you can watch it go through its paces.

Thanks to [Jess] for the tip!