Oil-Based Sprengel Pump Really Sucks

September 17, 2025 by 21 Comments

Have you heard of the Sprengel pump? It’s how they drew hard vacuum back before mechanical pumps were perfected — the first light bulbs had their vacuums drawn with Sprengel pumps, for example. It worked by using droplets of a particular liquid to catch air particles, and push them out a narrow tube, thereby slowly evacuating a chamber. The catch is that that liquid used to be mercury, which isn’t something many of us have on hand in kilogram quantities anymore. [Gabriel Wolffe] had the brainwave that one might substitute modern vacuum pump oil for mercury, and built a pump to test that idea.

Even better, unlike the last (mercury-based) Sprengel pump we saw, [Gabriel] set up his build so that no glassblowing is required. Yes, yes, scientific glassblowing used to be an essential skill taught in every technical college in the world. Nowadays, we’re glad to have a design that lets us solder brass fittings together. Technically you still have to cut an eyedropper, but that’s as complex as the glasswork gets. Being able to circulate oil with a plastic tube and peristaltic pump is great, too.

If you try it, you need to spring for vacuum pump oil. This type of pump is limited in the vacuum it can draw by the vapor pressure of the fluid in use, and just any oil won’t do. Most have vapor pressures far in excess of anything useful. In the old days, only mercury would cut it, but modern chemistry has come up with very stable oils that will do nearly as well.

How well? [Gabriel] isn’t sure; he bottomed out his gauge at 30 inches of Mercury (102 kPa). It may not be any lower than that, but it’s fair to say the pump draws a healthy vacuum without any unhealthy liquid metals. Enough to brew up some tubes, perhaps.

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The Practicality Of Solar Powered Meshtastic

September 17, 2025 by 17 Comments

A Meshtastic node has been one of the toys of the moment over the last year, and since they are popular with radio amateurs there’s a chance you’ll already live within range of at least one. They can typically run from a lithium-ion or li-po battery, so it’s probable that like us you’ve toyed with the idea of running one from a solar panel. It’s something we have in common with [saveitforparts], whose experiments with a range of different solar panels form the subject of a recent video.

He has three different models: one based around a commercial solar charger, another using an off-the-shelf panel, and a final one using the panel from a solar garden light. As expected the garden light panel can’t keep an ESP32 with a radio going all day, but the other two manage even in the relatively northern climes of Alaska.

As a final stunt he puts one of the nodes out on a rocky piece of the southern Alaskan coastline, for any passing hacker to find. It’s fairly obviously in a remote place, but it seems passing cruise ships will be within its range. We just know someone will take up his challenge and find it.

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Reviewing Deluxe Paint, 40 Years On

September 16, 2025 by 22 Comments

When Deluxe Paint came out with the original Amiga in 1985, it was the killer app for the platform. [Christopher Drum] starts his recent article on just that note, remembering the day he and his mother walked into a computer store, and walked out with a brand new Amiga… thanks entirely to Deluxe Paint. Forty years on, how well can this killer app compete?

[Christopher] isn’t putting Deluxe Paint head-to-head with modern Photoshop; they’re hardly in the same class. Not Photoshop, no, but modern applications that do what Deluxe Paint did so well: pixel art. There was no need to call it pixel art back then, no, but with the resolutions on hand, all digital art was pixel art in 1985.

Or 1989, which is when Deluxe Paint III came out– that’s the last version written by Dan Silva and coincidentally the last version [Christopher] owned, and the one he focuses in on his tests. It has held up amazingly well.

Sure, you don’t get a full 24-bit colour palette, but most pixel artists stick to limited palettes still anyway. You don’t quite get a modern UI, but presence of useful keyboard shortcuts allows a Hands-On-Keybord-And-Mouse (We’ll call it HOKAM, in honour of HOTAS in aerospace) workflow that is incredibly efficient.

About the only things [Christopher] found Deluxe Paint III lacked compared to its successors were a proper layering system, and of course the infinite undo we’ve all gotten so used to. (DPIII has an undo button, but it could only store one operation.) He also complained about cursor latency for some brushes, but we wonder if that might have had something to do with Windows and the emulation layer adding a delay. One thing Amiga was always known for back in the day was the snappy cursor movement, even when the processor was loaded.

There were just as many features he found had been forgotten in the new generation — like palatte swapping animations, or flood-filling line gradients.

It’s a small detail, but that’s a nice gradient tool.

Anyone who owned an Amgia probably has fond memories of it, but alas, in spite of Commodore’s recent resurrection, we’re not likely to see a new one soon. On the other hand, at least when it comes to pixel art, there’s apparently no need to upgrade.

via reddit.

(Thumbnail and header image by Avril Harrison, distributed by Electronic Arts with Deluxe Paint.)

A piece of perovskite crystal

Perovskite Solar Cell Crystals See The Invisible

September 16, 2025 by 14 Comments

A new kind of ‘camera’ is poking at the invisible world of the human body – and it’s made from the same weird crystals that once shook up solar energy. Researchers at Northwestern University and Soochow University have built the first perovskite-based gamma-ray detector that actually works for nuclear medicine imaging, like SPECT scans. This hack is unusual because it takes a once-experimental lab material and shows it can replace multimillion-dollar detectors in real-world hospitals.

Current medical scanners rely on CZT or NaI detectors. CZT is pricey and cracks like ice on a frozen lake. NaI is cheaper, but fuzzy – like photographing a cat through steamed-up glass. Perovskites, however, are easier to grow, cheaper to process, and now proven to detect single photons with record-breaking precision. The team pixelated their crystal like a smartphone camera sensor and pulled crisp 3D images out of faint radiation traces. The payoff: sharper scans, lower radiation doses, and tech that could spread beyond rich clinics.

Perovskite was once typecast as a ‘solar cell wonder,’ but now it’s mutating into a disruptive medical eye. A hack in the truest sense: re-purposing physics for life-saving clarity.

Raytracing makes the design easier, but the building is still as tricky as ever.

A 10″ Telescope, Because You Only Live Once

September 16, 2025 by 21 Comments

Why build a telescope? YOLO, as the kids say. Having decided that, one must decide what type of far-seer one will construct. For his 10″ reflector, [Carl Anderson] once again said “Yolo”— this time not as a slogan, but in reference to a little-known type of reflecting telescope.

Telescope or sci-fi laser gun? YOLO, just try it.

The Yolo-pattern telescope was proposed by [Art Leonard] back in the 1960s, and was apparently named for a county in California. It differs from the standard Newtonian reflector in that it uses two concave spherical mirrors of very long radius to produce a light path with no obstructions. (This differs from the similar Schiefspiegler that uses a convex secondary.) The Yolo never caught on, in part because of the need to stretch the primary mirror in a warping rig to correct for coma and astigmatism.

[Carl] doesn’t bother with that, instead using modern techniques to precisely calculate and grind the required toric profile into the mirror. Grinding and polishing was done on motorized jigs [Carl] built, save for the very final polishing. (A quick demo video of the polishing machine is embedded below.)

The body of the telescope is a wooden truss, sheathed in plywood. Three-point mirror mounts alowed for the final adjustment. [Carl] seems to prefer observing by eye to astrophotography, as there are no photos through the telescope. Of course, an astrophotographer probably would not have built an F/15 (yes, fifteen) telescope to begin with. The view through the eyepiece on the rear end must be astounding.

If you’re inspired to spend your one life scratch-building a telescope, but want something more conventional, check out this comprehensive guide. You can go bit more modern with 3D printed parts, but you probably don’t want to try spin-casting resin mirrors. Or maybe you do: YOLO!

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Making A Laptop With A Mechanical Keyboard

September 16, 2025 by 14 Comments

A laptop is one of the greatest tools at the disposal of a hacker. They come in all manner of shapes and sizes with all manner of features. But perhaps the greatest limit held by all laptops is their chiclet keyboard. While certainly serviceable, a proper mechanical keyboard will always reign supreme, which is why [flurples] built a laptop around a mechanical keyboard. 

Such a keyboard could not fit inside any normal laptop, so a custom machined case was in order. The starting point was a standard Framework Laptop 13. Its open source documentation certainly helped the project, but numerous parts such as the audio board and fingerprint sensor are not documented making for a long and tedious process. But the resulting machined aluminum case looks at least as good as a stock Framework chassis, all be it, quite a bit thicker.

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How To Have A Medium Format Camera Without Breaking The Bank

September 16, 2025 by 11 Comments

For most people, experimentation with film photography comes in the form of the 35 mm format. Its ubiquity in snapshot photography means cameras are readily available at all levels, and the film offers a decent compromise between resolution and number of shots per dollar spent.

For those who wish to take their film photography further there’s the so-called medium format 120 roll film, but here opting for a higher-end camera can become expensive. Fortunately [Javier Doroteo] is here with a 3D printed medium format camera designed to use lenses intended for the Mamiya Press cameras, and from where we’re sitting it looks very nicely designed indeed.

All the files can be found on Printables along with a list of the other parts required. It’s made simple by the Mamiya lenses incorporating the shutter, but there’s still a lot of attention that has been paid to the back of the camera. This is the third version of the design and it shows, details such as the film holder and light proofing are well thought out.

Photography is so often a world in which collecting the latest kit is seen as more important than the photographs themselves, so we like and encourage camera hackers as a reaction to all that. If you’d like to see another medium format camera, this certainly isn’t the first we’ve brought you.