Stop Ironing 3D Prints

February 25, 2026 by 14 Comments

If you want smooth top surfaces on your 3D printed parts, a common technique is to turn on ironing in your slicer. This causes the head to drag through the top of the part, emitting a small amount of plastic to smooth the surface. [Make Wonderful Things] asserts that you don’t need to do this time-consuming step. Instead, he proposes using statistical analysis to identify the optimal settings to place the top layer correctly the first time, as shown in the video below.

The parameters he thinks make a difference are line width, flow ratio, and print speed. Picking reasonable step sizes suggested that there were 19,200 combinations of settings to test. Obviously, that’s too many, so he picked up techniques from famous mathematician [George E. P. Box] and also used Bayesian analysis to reduce the amount of printing required to converge on the perfect settings.

Did it work? Judging from the video, it appears to have done so. The best test pieces looked as good as the one that used traditional ironing. Compared to ironing, the non-ironed parts saved about 34% of print time. Not bad.

Of course, there are variations on traditional ironing, so your results may vary.

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Building An Interactive Climbing Wall

February 25, 2026 by 5 Comments

Climbing is a cool sport. With that said, like everything, it’s even better if you integrate lots of glowing colorful LEDs. To that end, [Superbender] worked up this fun climbing wall that features interactive lighting built right in.

Structurally, there’s nothing too wild going on here. It’s a wood-framed climbing structure that stands 10 meters long and 2.5 meters high, and can be covered in lots of climbing holds. It’s the electronic side of things where it gets fun. An Arduino Due is installed to run the show, hooked up with a small TFT display and some buttons for control. It’s then hooked up to control a whole bunch of LEDs and some buttons which are scattered all across the wall. It’s also paired with an Arduino Nano which runs sound feedback, and a 433 MHz remote for controlling the system at a distance.

[Superbender] uses the lighting for fun interactive games. One example is called Hot Lava, where after each climbing pass, more holds are forbidden until you can’t make the run anymore. Chase the Blues is another fun game, where you have to climb towards a given hold, at which point it moves and you have to scamper to the next one.

We’ve featured similar projects before from other inventive climbers. Video after the break.

Continue reading “Building An Interactive Climbing Wall” →

The metal comm badge and M5stick on an LCARS mousepad

Control Your Smart Home With Trek-Inspired Comm Badge

February 25, 2026 by 27 Comments

One thing some people hate about voice control is that you need to have a process always running, listening for the wake word. If your system isn’t totally locally-hosted, that can raise some privacy eyebrows. Perhaps that’s part of what inspired [SpannerSpencer] to create this 24th century solution: a Comm Badge straight out of Star Trek: The Next Generation he uses to control his smart home.

This hack is as slick as it is simple. The shiny comm badge is actually metal, purchased from an online vendor that surely pays all appropriate license fees to Paramount. It was designed for magnetic mounting, and you know what else has a magnet to stick it to things? The M5StickC PLUS2, a handy ESP32 dev kit. Since the M5Stick is worn under the shirt, its magnet attached to the comm badge, some features (like the touchscreen) are unused, but that’s okay. You use what you have, and we can’t argue with how easy the hardware side of this hack comes together.

[Spanner] reports that taps to the comm badge are easily detected by the onboard accelerometer, and that the M5Stick’s microphone has no trouble picking up his voice. If the voice recordings are slightly muffled by his shirt, the Groq transcription API being used doesn’t seem to notice. From Groq, those transcriptions are sent to [Spanner]’s Home Assistant as natural language commands. Code for the com-badge portion is available via GitHub; presumably if you’re the kind of person who wants this, you either have HA set up or can figure out how.

It seems worth pointing out that the computer in Star Trek: TNG did have a wake word: “computer”. On the other hand it seemed the badges were used to interface with it just as much as the wake word on screen, so this use case is still show accurate. You can watch it in the demo video below, but alas, at no point does his Home Assistant talk back. We can only hope he’s trained a text-to-speech model to sound like Majel Barrett-Roddenberry. At least it gives the proper “beep” when receiving a command.

This would pair very nicely with the LCARS dashboard we featured in January. Continue reading “Control Your Smart Home With Trek-Inspired Comm Badge” →

What One-Winged Squids Can Teach The Airship Renaissance

February 25, 2026 by 18 Comments

It’s a blustery January day outside Lakehurst, New Jersey. The East Coast of North America is experiencing its worst weather in decades, and all civilian aircraft have been grounded the past four days, from Florida to Maine. For the past two days, that order has included military aircraft, including those certified “all weather” – with one notable exception. A few miles offshore, rocking and bucking in the gales, a U.S. Navy airship braves the storm. Sleet pelts the plexiglass windscreen and ice sloughs off the gasbag in great sheets as the storm rages on, and churning airscrews keep the airship on station.

If you know history you might be a bit confused: the rigid airship USS Akron was lost off the coast of New Jersey, but in April, not January. Before jumping into the comments with your corrections, note the story I’ve begun is set not in 1933, but in 1957, a full generation later.

The airship caught in the storm is no experimental Zeppelin, but an N-class blimp, the workhorse of the cold-war fleet. Yes, there was a cold war fleet of airships; we’ll get to why further on. The most important distinction is that unlike the last flight of the Akron, this story doesn’t end in tragedy, but in triumph. Tasked to demonstrate their readiness, five blimps from Lakehurst’s Airship Airborne Early-Warning Squadron 1 remained on station with no gaps in coverage for the ten days from January 15th to 24th. The blimps were able to swap places, watch-on-watch, and provide continuous coverage, in spite of weather conditions that included 60 knot winds and grounded literally every other aircraft in existence at that time. Continue reading “What One-Winged Squids Can Teach The Airship Renaissance” →

Sub-Second Volumetric 3D Printing

February 25, 2026 by 14 Comments

One of the more promising 3D printing technologies that hasn’t quite yet had its spotlight is volumetric 3D printing. Researchers from the Department of Automation, Tsinghua University, have developed a new method that uses a high-speed periscope instead of rotating the printing volume — resulting in print times of less than one second.

Normal volumetric printing uses a rotating volume of photosensitive resin to print nearly any geometry desired. However, this method presents issues when printing at high speeds. If you rapidly rotate a liquid, it won’t exactly stay still. So why not rotate the projector itself? This change also allows the use of less viscous resins, which is particularly useful if you want to pump fluid around.

Why would you want to pump around liquid? Scalability of course! Printing in seconds while pumping the results into a collection vessel would allow for mass production more flexible than traditional ejection methods. The researchers manage to keep quality high with some fancy algorithmic correction, which allows for accuracy on the scale of μm.

While this technology still doesn’t find a common space among average hobbyists, this may soon change…especially with these mass manufacturing capabilities. For similar volumetric printing capabilities, check out xolography.

Restoring A Yamaha DX7 Synthesizer

February 25, 2026 by 3 Comments

The Yamaha DX7 is one of the most iconic synthesizers that emerged in the early 1980s, and is still very popular today. That said, with even the newest of these having left the factory back in 1989, the average DX7 can use a bit of tender love and care. In particular the battered DX7 that [Drygol] recently got handed to ‘just fix the PSU voltage switch’. As it turned out, this poor DX7 had a few more issues than just a busted voltage selector.

Just a hint of cosmetic damage on this Yamaha DX7. (Credit: Drygol)
Just a hint of cosmetic damage on this Yamaha DX7.

In addition to missing slider caps and a vanished key, the paint of the case also had clearly lost a fight with various hard surfaces in addition to a thick coating of unidentifiable dust and grime inside the synthesizer. Feeling a pang of sympathy, [Drygol] thus decided to give the old girl a complete restoration.

After taking the synthesizer apart for a good scrub-down, the parts were assessed for further damage. This turned out to include the plastic stubs on some keys to hold a spring for which a replacement was modelled and 3D printed, along with replacements for the missing slider caps.

Next the case was painted, with a brand new Yamaha DX7 vinyl logo rather than trying to fix up the old paint and logo. With the outside fixed up, the broken and dodgy controls, audio jacks and potentiometers were addressed, followed by the busted onboard battery, leaving just the original voltage selector. This one got replaced by an IEC 60320 C13 jack, with the transformer hardwired for 230 VAC input, out of convenience grounds.

We’re always excited when [Drygol] sends in another restoration project — from a glowing Amiga 500 to vacuum-formed keycap covers, they’re always remarkable displays of ingenuity.

A brass and steel mechanism is shown, with a series of rotary dials on the front. Each dial is made out of a brass ring around the stone center. A man’s hand is behind the mechanism, turning a handle.

Interplanetary Clock Keeps Time Across The Solar System

February 24, 2026 by 6 Comments

There are some clocks, mostly in or around international airports, which have multiple faces to show the time at various cities around the world. Taking more a forward-looking approach is [Chronova Engineering], who built a clock to display the time on four different planets: Earth, Mars, Jupiter, and Saturn.

The clock doesn’t have any hands, but it uses rotating dials to represent a top-down view of each planet from it’s north pole. The dials have degree markings to represent rotation relative to each planet’s prime meridian; for the gas giants, rotation is measured by the rotation of the planet’s core. Each dial’s center is made out of a circular stone tile with patterns similar to those seen on the planet; Earth, for example, is represented with sodalite. Three pointers mounted around the dial indicate the longitudes which are currently experiencing sunrise, noon, and sunset. The mechanism can be turned with a handle or a knob, and a mechanical counter keeps track of the number of Earth days that have passed.

Continue reading “Interplanetary Clock Keeps Time Across The Solar System” →