Hack A Padlock Key From Plastic Scraps

November 16, 2015 by Dan Maloney 11 Comments

Not too many years ago, if you wanted a decent copy of a key made, you had to head to either a locksmith’s shop or the nearest hardware store, where real people actually knew their trade. Now we generally take our keys to the Big Orange Box o’ Stuff and have it copied by a semi-automated machine, or even feed it into one of the growing number of fully automated key-copying kiosks, with varying results. But as [BlueMacGyver] shows us, a serviceable padlock key can be whipped up quickly at home with nothing but scraps.

The video below details the process – soot the profile of the key with a lighter, transfer the carbon to some stiff plastic with Scotch tape, and cut out the profile. With a little finagling the flat copy makes it into the lock and opens it with ease. Looks like the method could be applied to locks other than padlocks. As for raw material, we think we’ve found a use for all those expired credit cards collecting in the desk drawer.

We’ve given a lot of coverage lately to hacks involving locks, including copying keys from photos and making bump keys with a 3D printer. But we like this hack for its simplicity. True, you need physical access to the key to copy it, and that limits the hack’s nefarious possibilities. But maybe that’s not such a bad thing.

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An E-Waste 3D Printer For Every Child?

November 14, 2015 by Dan Maloney 62 Comments

The lofty goal of making sure every school kid has access to a laptop has yet to be reached when along comes an effort to put a 3D printer in the hands of every kid. And not just any printer – a printer the kid builds from a cheap kit of parts and a little e-waste.

The design of the Curiosity printer is pretty simple, and bears a strong resemblance to an earlier e-waste 3D printer we covered back in December. This one has a laser-cut MDF frame rather than acrylic, but the guts are very similar – up-cycled DVD drives for the X- and Z-axes, and a floppy drive for the Y-axis. A NEMA 17 frame stepper motor provides the oomph needed to drive the filament into an off-the-shelf hot end, and an Arduino runs the show. The instructions for assembly are very clear and easy to follow, although we suspect that variability in the sizes of DVD and floppy drives could require a little improvisation at assembly time. But since the assembly of the printer is intended to be as educational as its use, throwing a little variability into the mix is probably a good idea.

The complete kit, less only the e-waste drives and power supply, is currently selling for $149USD. That’s not exactly free, but it’s probably within range of being funded by a few bake sales. Even with the tiny print volume, this effort could get some kids into 3D printers early in their school career.

Heat Duct Rover Explores Stink, Rescues Flashlight

November 12, 2015 by Dan Maloney 32 Comments

It all started with a bad smell coming from the heat register. [CuddleBurrito] recalled a time when something stinky ended up in the ductwork of his folks’ house which ended up costing them big bucks to explore. The hacker mindset shies away from those expenditures and toward literally rolling your own solution to investigating the funk. In the process [CuddleBurrito] takes us on a journey into the bowels of his house.

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Are Your 3D Prints Toxic?

November 11, 2015 by Dan Maloney 78 Comments

With the rising popularity and increasing availability of 3D printers, it was inevitable that someone would start looking into the potential environmental impact presented by them. And now we have two researchers from the University of California Riverside sounding the alarm that certain plastics are toxic to zebrafish embryos (abstract only; full paper behind a paywall).

As is often the case with science, this discovery was serendipitous. Graduate student [Shirin Mesbah Oskui] was using 3D printed tools to study zebrafish embryos, a widely used model organism in developmental biology, but she found the tools were killing her critters. She investigated further and found that prints from both a Stratasys Dimension Elite FDM printer and from a Formlabs Form 1+ stereolithography printer were “measurably toxic” to developing zebrafish embryos. The resin-based SLA printed parts were far worse for the fish than the fused ABS prints – 100% of embryos exposed to the Form 1+ prints were dead within seven days, and the few that survived that long showed developmental abnormalities before they died. Interestingly, the paper also describes a UV-curing process that reduces the toxicity of the SLA prints, which the university is patenting.

Of course what’s toxic to zebrafish is not necessarily a problem for school kids, as the video below seems to intimate. Still, this is an interesting paper that points to an area that clearly needs more investigation.

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The Running Cat

November 11, 2015 by Dan Maloney 58 Comments

Cats are great to have around, but they need exercise. If you’re not in a position to let the cat outdoors, you need to look to something else when kitty wakes up bored from her 23 hour nap. Cat playscapes are useful diversions, but this is the first time we’ve considered real exercise equipment. Let’s get our feline friends their exercise fix with a hamster-esque cat exercise wheel.

[bbarlowski]’s design is simple but very clever, and almost looks like something you’d find flat-packed at IKEA. Built of CNC-milled birch plywood, the wheel rims snap together like puzzle pieces while the floor has tabs that slot into the rims. The tension of the bent floor panels locks everything together and makes for a smart looking wheel. The video after the break shows [Kuna the Maine Coon cat] in action on the wheel, and outlines a few plans for expansion, including adding an Arduino to monitor kitty’s activity and control both an RGB LED strip for mood lighting and a cat treat dispenser for positive reinforcement of the exercise regimen.

The project mounted an unsuccessful campaign in March and they’ve made the DXF cutting files available for download. Of course if it’s too much plywood and not enough Arduino for you, just build the Arduspider to torture – err, entertain your cat.

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A Peek Under The Hood Of The 741 Op-Amp

October 31, 2015 by Dan Maloney 9 Comments

First introduced as an IC back in 1968, but with roots that go back to 1941, the 741 has been tweaked and optimized over the years and is arguably the canonical op-amp. [Ken Shirriff] decided to take a look inside everybody’s favorite op-amp, and ended up with some good-looking photomicrographs and a lot of background on the chip.

Rather than risk the boiling acid method commonly used to decap epoxy-potted ICs, [Ken] wisely chose a TO-99 can format to attack with a hacksaw. With the die laid bare for his microscope, he was able to locate all the major components and show how each is implemented in silicon. Particularly fascinating is the difference between the construction of NPN and PNP transistors, and the concept of “current mirrors” as constant current sources. And he even whipped up a handy interactive chip viewer – click on something in the die image and find out which component it is on the 741 schematic. Very nice.

We’ve seen lots of chip decappings before, including this reveal of TTL and CMOS logic chips. It’s nice to see the guts of the venerable 741 on display, though, and [Ken]’s tour is both a great primer for the newbie and a solid review for the older hands. Don’t miss the little slice of history he included at the end of the post.

Hacking When It Counts: Surviving The Burma Death Railway

October 28, 2015 by Dan Maloney 59 Comments

In the early days of World War II, the Japanese army invaded Burma (now Myanmar) and forced an end to British colonial rule there. Occupying Burma required troops and massive amounts of materiel, though, and the Japanese navy was taking a beating on the 2,000 mile sea route around the Malay Peninsula. And so it was decided that a railway connecting Thailand and Burma would be constructed through dense tropical jungle over hilly terrain with hundreds of rivers, including the Kwae Noi River, made famous by the Hollywood treatment of the story in The Bridge on the River Kwai. The real story of what came to be known as the Burma Death Railway is far grislier than any movie could make it, and the ways that the prisoners who built it managed to stay alive is a fascinating case study in making do with what you’ve got and finding solutions that save lives.

Nutrition from Next-to Nothing

AWM_P00761_011-540 — POWs in camp. [Source: The Thai-Burma Railway and Hellfire Pass]

Labor for the massive project was to come from the ultimate spoil of war – slaves. About 250,000 to 300,000 slaves were used to build the Burma-Siam Railway. Among them were about 60,000 Allied prisoners of war, primarily Australian, Dutch, British and American. POWs were singled out for especially brutal treatment by the Japanese and Korean guards, with punishment meted out with rifle butt and bamboo pole.

With the POWs was Doctor Henri Hekking, who had been born and raised in the former Dutch East Indies colony of Java (now Indonesia). He had spent his early years with his grandmother, a master herbalist who served as “doctor” for the native villagers. Inspired by his oma’s skill and convinced that the cure for any endemic disease can be found in the plants in the area, Dr. Hekking returned to Java as an officer in the Dutch army after completing medical school in the Netherlands.

After his capture by the Japanese, Dr. Hekking did everything he could to help his fellow POWs despite the complete lack of medical supplies, all the while suffering from the same miserable treatment. Hekking realized early on that the starvation rations the POWs endured were the main cause of disease in the camps; a cup of boiled white rice doesn’t provide much energy for men building a railway by hand in jungle heat, and provides none of the B vitamins needed by the body.

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