Stop Ironing 3D Prints

February 25, 2026 by Al Williams 5 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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TAT-8 — The First Transatlantic Fiber — Rises Again

February 24, 2026 by Al Williams 21 Comments

While you may have never heard of TAT-8, there is a good chance you sent some data through it. TAT-8 was the 8th transatlantic communications cable and the first transatlantic fiber-optic cable, carrying 560 Mbit/s on two fibers between Tuckerton, New Jersey, and, thanks to an underwater splitting device, Widemouth Bay, England, and Penmarch, France. Construction of the cable began in 1998. Later that year, the first call, made by [Issac Asimov] took place. The cable was retired in 2002. Now, Subsea Environmental Services is recovering the cable for recycling.

The 6,000 km cable was built by a consortium of companies including AT&T, France Télécom, and British Telecom. The 1.3 micron fiber used special optical repeaters about 40 km apart and cost about $335 million (just shy of a billion dollars today). Designers were optimistic, with some claiming the cable would end the need for future cables or, at least, that the cable would not reach capacity for ten years or more. In reality, the cable was saturated within 18 months. Turns out, the equivalent of 40,000 phone lines wasn’t enough.

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Peltier Fridges Have Early Death

February 24, 2026 by Al Williams 20 Comments

If you know about Peltier modules, a solid-state fridge seems like an easy project. Pump 12V into the module, include a heat sink and a fan. Then you are done, right? According to [Peltier Power], this is not the way to design things, but it is common enough to give these units a reputation for failing quickly.

The problem is that while it makes sense that an inefficient Peltier module needs more power to get more cooling. But the reality is in practical applications, many designs push the current up when it should be moving it down. The curve describes a parabola, and you can be on the high side or low side and still get the same result. But obviously, you don’t want to put in more current and get the same cooling that you could get with lower currents.

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X-Ray A PCB Virtually

February 23, 2026 by Al Williams 18 Comments

If you want to reverse engineer a PC board, you could do worse than X-ray it. But thanks to [Philip Giacalone], you could just take a photo, load it into PCB Tracer, and annotate the images. You can see a few of a series of videos about the system below.

The tracer runs in your browser. It can let you mark traces, vias, components, and pads. You can annotate everything as you document it, and it can even call an AI model to help generate a schematic from the net list.

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Tech In Plain Sight: Projection Clocks

February 23, 2026 by Al Williams 10 Comments

You wake up in the middle of the night. Is it time to get up? Well, you can look at the nightstand clock. Unless your partner is in the way. Whoops. Even then, without your glasses, the time is just a fuzzball of light. You could ask Alexa, but that’s sure to wake your partner, too. The answer is a projection clock. In its modern form, it shoots a digital time display on a wall or ceiling with digits so large that you don’t need your glasses. If you can see the ceiling, you can tell what time it is.

New Tech

A modern invention, of course. No, not really. According to [Roger Russel], a UK patent in 1909 used an analog clock face and lightbulbs to project the clock face and hands on the ceiling. Unfortunately, [Roger’s] website is no more, but the Wayback Machine is on the job. You can see a device of the same type at the British Museum.

A modern projection clock on the ceiling.

In 1938, [Leendert Prins] filed for a patent on a similar projection clock. Sometimes known as “ceiling clocks” or “night clocks,” these devices often have a regular clock visible as well as a way to project the time. In the old days, this was often an image of a translucent analog clock lit up by light bulbs. In the modern era, it is almost always either LEDs or an LCD with a halogen backlight. Of course, there are many variations. A clock might use numbers on a rotating drum with a lamp behind it, for example.

Development

It isn’t hard to imagine someone putting a pocket watch in a magic lantern as a prototype. In general, some bright light source has to pass through a condenser lens. The light then travels through the LCD or translucent clock face. Finally, a projector lens expands the image.

We couldn’t find much about the actual history of old projection clocks outside of [Roger’s] defunct website. But if you can project an image and build a clock, all you need is the idea to combine them.

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Nuclear Waste Remediation By Proton Beam

February 23, 2026 by Al Williams 36 Comments

One of the issues with nuclear power plants is that they produce long-lived radioactive waste. Storing spent nuclear fuel is a real problem. However, researchers at the Department of Energy’s Thomas Jefferson National Accelerator Facility have made strides not only to produce more electricity from spent fuel but also to break it down into shorter-lived nuclear waste. [Aman Tripathi] shares the details about NEWTON, a program to fire high-energy protons at a target to produce a flood of neutrons that can interact with nuclear waste. You can read the original press release, too.

Short-lived, of course, is a relative term. Unprocessed spent fuel may be dangerous for about 100,000 years. After the proposed processing, the danger period is down to “only” 300 years. On the plus side, the process generates a lot of heat, which you can convert to electricity in the usual way.

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Calculus By Oscilloscope

February 23, 2026 by Al Williams 17 Comments

Even entry-level oscilloscopes today have simple math functions such as adding or subtracting two channels. But as [Arthur Pini] notes, more advanced scopes can now even do integration and differentiation. He writes about using these tools to make measurements on capacitors and inductors. The post in EDN is worth a read, even if your scope doesn’t offer this sort of math yet.

It makes sense that capacitors and inductors would benefit from this feature. After all, the current through a capacitor, for example, is proportional to the rate of change in the voltage across it. That’s a derivative. Since the scope can measure voltages, it can also differentiate to find the current.

The same idea applies to inductors, where the current through an inductor is related to the integral of the voltage across it. It is a simple matter to measure the voltages and perform an integration to determine the current.

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