A Lockpicking Robot That Can Sense The Pins

July 21, 2025 by Maya Posch 15 Comments

Having a robot that can quickly and unsupervised pick any lock with the skills of a professional human lockpicker has been a dream for many years. A major issue with lockpicking robots is however the lack of any sensing of the pins – or equivalent – as the pick works its magic inside. One approach to try and solve this was attempted by the [Sparks and Code] channel on YouTube, who built a robot that uses thin wires in a hollow key, load cells and servos to imitate the experience of a human lockpicker working their way through a pin-tumbler style lock.

Although the experience was mostly a frustrating series of setbacks and failures, it does show an interesting approach to sensing the resistance from the pin stack in each channel. The goal with picking a pin-tumbler lock is to determine when the pin is bound where it can rotate, and to sense any false gates from security pins that may also be in the pin stack. This is not an easy puzzle to solve, and is probably why most lockpicking robots end up just brute-forcing all possible combinations.

Perhaps that using a more traditional turner and pick style approach here – with one or more loadcells on the pick and turner- or a design inspired by the very effective Lishi decoding tools would be more effective here. Regardless, the idea of making lockpicking robots more sensitive is a good one, albeit a tough nut to crack. The jobs of YouTube-based lockpicking enthusiasts are still safe from the robots, for now.

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Don’t Turn That Old System On, First Take It Apart

July 21, 2025 by Maya Posch 35 Comments

When you first get your hands on an old piece of equipment, regardless of whether it’s an old PC or some lab equipment, there is often the temptation to stick a power lead into it and see what the happy electrons make it do. Although often this will work out fine, there are many reasons why this is a terrible idea. As many people have found out by now, you can be met by the wonderful smell of a Rifa capacitor blowing smoke in the power supply, or by fascinatingly dangly damaged power wires, as the [Retro Hack Shack] on YouTube found recently in an old Gateway PC.

Fortunately, this video is a public service announcement and a demonstration of why you should always follow the sage advice of “Don’t turn it on, take it apart”. Inside this Gateway 2000 PC from 1999 lurked a cut audio cable, which wasn’t terribly concerning. The problem was also a Molex connector that had at some point been violently ripped off, leaving exposed wiring inside the case. The connector and the rest of the wiring were still found in the HDD.

Other wires were also damaged, making it clear that the previous owner had tried and failed to remove some connectors, including the front panel I/O wiring. Thankfully, this PC was first torn apart so that the damage could be repaired, but it shows just how easily a ‘quick power-on check’ can turn into something very unpleasant and smelly.

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Reverse Engineering A ‘Tony’ 6502-based Mini Arcade Machine

July 21, 2025 by Maya Posch 15 Comments

The mainboard of the mini arcade unit with its blob chip and EEPROM. (Credit: Poking Technology, YouTube)

For some reason, people are really into tiny arcade machines that basically require you to ruin your hands and eyes in order to play on them. That said, unlike the fifty gazillion ‘retro consoles’ that you can buy everywhere, the particular mini arcade machine that [David Given] of [Poking Technology] obtained from AliExpress for a teardown and ROM dump seems to have custom games rather than the typical gaggle of NES games and fifty ROM hack variations of each.

After a bit of gameplay to demonstrate the various games on the very tiny machine with tiny controls and a tiny 1.8″, 160×128 ST7735 LC display, the device was disassembled. Inside is a fairly decent speaker, the IO board for the controls, and the mainboard with an epoxy blob-covered chip and the SPI EEPROM containing the software. Dumping this XOR ‘encrypted’ ROM was straightforward, revealing it to be a 4 MB, W23X32-compatible EEPROM.

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When A Record Player Doesn’t Work Due To Solid State Grease

July 20, 2025 by Maya Posch 24 Comments

Normally, mechanical devices like record players move smoothly, with well-greased contact surfaces enabling the tone arm to automatically move, the multi-record mechanism to drop down a fresh disc, and the listener to have a generally good time. Unfortunately, the 1972-era ITT KP821 record player that [Mark] got recently handed by a friend wasn’t doing a lot of moving, with every part of the mechanism seemingly frozen in place, though the current owner wasn’t certain that they were doing something wrong.

Fortunately, this record player was in exceptionally good condition.. The primary failure was that the BSR record player mechanism, with its many touching metal surfaces, was suffering from a bad case of solidified grease. Although this is easily fixed with some IPA and a lot of elbow grease, the biggest trick with these mechanisms is putting it back together after cleaning, with many seemingly randomly shaped parts and every single E-clip that the manufacturer could design for and source at the time.

With that complete, this just left some pot cleaning and replacing a busted fuse in the amplifier section. The selenium rectifier was still functional, as were the SGS TAA621AX1 audio amplifier ICs. Despite the age of this ‘portable’ record player, both its BSR mechanism and the twin speakers that are part of the record player are in remarkably good condition. Much like with a car, it seems that you just have to swap out the liquid-y elements before they turn into a solid.

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Elegoo Rapid PETG Vs PETG Pro: Same Price, Similar Specs, Which To Buy?

July 19, 2025 by Maya Posch 16 Comments

Even within a single type of FDM filament there is an overwhelming amount of choice. Take for example Elegoo’s PETG filament offerings, which include such varieties like ‘Pro’ and ‘Rapid’. Both cost the same, but is there a reason to prefer one over the other, perhaps even just for specific applications? To test this, [Dr. Igor Gaspar] over at the My Tech Fun YouTube channel bought some spools of these two filaments and subjected both to a series of tests.

Obviously, the Rapid filament is rated for higher extrusion speeds – <270 vs <600 mm/s – while the website claims a higher required nozzle temperature that confusingly does not match those listed on the spool. There are quite a few differences in the listed specifications, including the physical and mechanical properties, which make it hard to draw any immediate conclusions. Could you perhaps just use Rapid PETG and forget about the Pro version?

Test objects were printed with a Bambu Lab P1P with an AMS unit. After calibrating the ideal temperature for each filament, a tensile break test gave a win to the Rapid PETG, followed by a layer adhesion test win. This pattern continued across further tests, with Rapid PETG either matching or beating the Pro PETG.

There are only two advantages of the Pro version that can be seen here, which are less moisture sensitivity and stringing risk, and you of course get the luxury cardboard spool with the closed edges. Whether that’s enough to make you go ‘Pro’ remains to be seen, of course.

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Opening A Six-Lock Safe With One Key Using Brunnian Links

July 16, 2025 by Maya Posch 6 Comments

Brunnian links are a type of nontrivial link – or knot – where multiple linked loops become unlinked if a single loop is cut or removed. Beyond ‘fun’ disentanglement toys and a tantalizing subject of academic papers on knot theory, it can also be used for practical applications, as demonstrated by [Anthony Francis-Jones] in a recent video. In it we get a safe that is locked with multiple padlocks, each of which can unlock and open the safe by itself.

This type of locked enclosure is quite commonly used in military and other applications where you do not want to give the same key to each person in a group, yet still want to give each person full access. After taking us through the basics of Brunnian links, including Borromean rings, we are introduced to the design behind the safe with its six padlocks.

As a demonstration piece it uses cheap luggage padlocks and Perspex (acrylic) rods and sheets to give a vibrant and transparent view of its workings. During the assembly it becomes quite apparent how it works, with each padlock controlling one direction of motion of a piece, each of which can be used to disassemble the entire locking mechanism and open the safe.

Brunnian links are also found in the braids often made by children out of elastic bands, which together with this safe can be used to get children hooked on Brunnian links and general knot theory.

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Caltech Scientists Make Producing Plastics From CO2 More Efficient

July 16, 2025 by Maya Posch 26 Comments

For decades there has been this tantalizing idea being pitched of pulling CO₂ out of the air and using the carbon molecules for something more useful, like making plastics. Although this is a fairly simple process, it is also remarkably inefficient. Recently Caltech researchers have managed to boost the efficiency somewhat with a new two-stage process involving electrocatalysis and thermocatalysis that gets a CO₂ utilization of 14%, albeit with pure CO₂ as input.

The experimental setup with the gas diffusion electrode (GDE) and the copolymerization steps. (Credit: Caltech)

The full paper as published in Angewandte Chemie International is sadly paywalled with no preprint available, but we can look at the Supplemental Information for some details. We can see for example the actual gas diffusion cell (GDE) starting on page 107 in which the copper and silver electrodes react with CO₂ in a potassium bicarbonate (KHCO₃) aqueous electrolyte, which produces carbon monoxide (CO) and ethylene (C₂H₄). These then react under influence of a palladium catalyst in the second step to form polyketones, which is already the typical way that these thermoplastics are created on an industrial scale.

The novelty here appears to be that the ethylene and CO are generated in the GDEs, which require only the input of CO₂ and the potassium bicarbonate, with the CO2 recirculated for about an hour to build up high enough concentrations of CO and C₂H₄. Even so, the researchers note a disappointing final quality of the produced polyketones.

Considering that a big commercial outfit like Novomer that attempted something similar just filed for Chapter 11 bankruptcy protection, it seems right to be skeptical about producing plastics on an industrial scale, before even considering using atmospheric CO₂ for this at less than 450 ppm.