CNC-cutting a precision DIY cycloidal gearbox from steel. He bought dowel pins for the rollers. And had to start over. #mechanical #video #toread
#YiZhiZhu steampunk taxidermy #video where he seems to be modifying a Spongebob doll? Wrapping copper wire around a steel rod? Epoxying watch parts in? Hot-gluing in a laser diode? Dremeling out most of the original plastic? Vacuum tubes with UV LEDs, other electronic parts, etc. Indeed looks very steampunky. Cyborg Patrick sculpture.
#VICE on Singapore’s remote-controlled cyborg insects: aerospace engineer Dr. Hirotaka Sato and his student Cao Feng at Nanjing Techncal University (in Singapore?) are controlling eight muscles of large live beetles with wires to make them walk, and his students Li Yao and Thang are working on controlling their flight. #video
#SteadyCraftin on how to make and use toy wax #video
DIY betavoltaics #bootstrapping #video Chinese Betavolt Corp. is using diamond semiconductors; their BV100 produces 100μW at 3V for 50 years from nickel-63, package size 15mm × 15mm × 5mm. So Robert Murray-Smith decided to make his own out of an americium smoke alarm (1 microcurie, 37kBq, 0.3μg, working out to 6 femtoamps, with half-life of 432 years, since it’s isotope 241) and a 2N3055 TO-3 power transistor. He measures 130mV of alphavoltaic production from his decapped 2N3055 but doesn’t measure the current, but presumably it would be on the order of half a femtowatt. NurdRage’s tritium-keychain-powered solar cells (being commercialized by Arkenlight as Betalight) are much more practical, but shorter-lived.
#bootstrapping a handheld metal smith’s forge (but you can’t hold it while you’re using it) #manufacturing #video #toread
are Chinese motorcycles taking over? #video consisting apparently entirely of stock footage with a voiceover. #Plonk to "bart".
can #ultrasonic waves eat metal? #video demonstrating ultrasonic cleaning and giving an introduction to acoustics. Claims that sound pressure at a given “amplitude” is proportional to frequency, but the WP article on the absolute threshold of hearing says that 20μPa = 0.98pW/m² at 1 atm and 25°C without giving a frequency, so I’m not sure what definition of “amplitude” would make this true. Displacement, I guess? Immediately afterwards, though, he equates amplitude to loudness, so I guess he’s just wrong. Also the video has lots of worthless talking head footage. By “eat metal” apparently he means tear gold leaf apart. But he says it’s “brass foil”, thickness unspecified. I guess we can relegate "The Action Lab" to the #fakenews #misinformation category.
diamond in piranha. #video #materials another #The-Action-Lab video, but not full of misinformation as far as I can tell. Also includes demos of piranha on a cellulose sponge and a hot dog. Diamond results: inconclusive.
why Wankel rotary engines bankrupt motorcycle manufacturers #mechanical #mechanisms #video. Very nice footage from “@Warped Perception” of a running Wankel engine, then a guy riding a 27hp Hercules W2000 from 01974 West Germany and posing sexily with it on the autumn leaves. Hmm, is it true that the Nazis fired Felix Wankel for being too militant and then he became SS? Yes, yes it is. 8½:1 compression ratio, which I guess is inherent to the geometry. And the Hercules mixed oil into the fuel like a two-stroke. Oh, and apparently insurance companies classified it has having three times the 294cc displacement it actually did, 882cc, presumably because it fires three times as often. That was the first Wankel motorcycle, but then Norton bought the assets and also went bankrupt. Suzuki didn’t go bankrupt but abandoned their Wankel cycle after 12 months, he says. Van Veen went bankrupt.
#the-Line in Saudi Arabia is apparently fixed? Explores nomadic cities. Oh, it’s a Canadian architect marketing her ideas to the Saudis. Lots of nice eye-candy of architectural visualizations, though. Too bad half the #video is wasted on footage of her face.
#bitluni made an ASIC #video. 165 designs on the chip (eFabless Tiny Tapeout 2, in 02022, US$300, from Matt Venn’s Zero to ASIC course), and he can test any of them; his design is a file of a three-frame 32×32 rickroll (512 bytes, GIF89a). He got back the chip 9 months later. More recent Tiny Tapeout runs are using much faster buses than the serial bus his chip used. Instead of JLCPCB or PCBWay he’s advertising PCB fab house Aisler in this video, who supports LCSC.
#SteveMould applies a cast saw to his skin #video Apparently new casts use a water-activated synthetic resin? But can still be cut by the same cast saws.
“EXO CARS: The Underground Cheap Supercar Slayers” seems to show a welded-tube frame? “semi-legal lightweight performance projects cost next to nothing” #video actually doesn’t contain much more info than that
airline #cold-plasma ozone generator #hardware teardown #video #toread
DIY plasma physics power source with a 20kV flyback transformer which looks like it came from a TV set (he recommends a miniature battery-powered TV from a thrift store). Looks like he’s using the flyback transistor and heatsink from the TV too; he says MX D363 / 2N3055 but the actual Fairchild part says MJE3055T on it. Then a couple of 2-watt resistors (220Ω and 20Ω) and that’s it. The 220-ohm resistor limits the current from the 12-volt source to the base, which also runs through a feedback coil on the transformer to turn it off, allowing the 20-ohm resistor to pull the base down to ground (or rather to keep the feedback coil from pulling it too far below ground). And then the primary coil is just connected through the collector to the grounded emitter with no resistance. He recommends using an ohmmeter to find a couple of sub-1Ω coils on the transformer to ID the primary and feedback coils. This is pretty similar to a Joule Thief. #hardware #video
bushcraft camping with coyotes & hunting my dinner #bootstrapping #video #toread
“DIY” ozone generator #video but he bought the power supply for US$3 on eBay, eliminating the DIY aspect. That power supply burned itself up, so he bought another one. The DIY part is that he put some stainless window steel screen into some borosilicate glass tubes and 3-D-printed endcaps.
#Angelito plasma thruster (ionic wind generator) #video #toread
#GreatScott build an HV generator. His HV transformer has a low-voltage feedback winding on the primary side which he uses to turn on an NPN BJT to ground, via a 100Ω resistor and a UF4007 diode on the base, which turns on the other (113μH) primary coil; apparently this makes a 19kHz blocking oscillator like a Joule Thief, but this time with a high-voltage secondary. He burned up his first transistor pretty soon by dissipating 2.8 watts. An IRF740 N-MOSFET died even sooner. So he switched to a flyback converter built around an IRF840 driven by an external square wave and a DRC snubber. He reports that above 200kHz he could no longer feel the shock, but did burn his skin. But it still wasn’t as efficient as he wanted, so he drove it with the ZVS oscillator he’d built previously for induction heating. #electronics #hardware #video
Alan Zhang’s DIY electric VTOL “flying car” #video looks like a small car, sure. 8 2-bladed propellers at the corners. Apparently #eVTOL is a thing now. Carbon-fiber-reinforced plastic tubes connect through FDM-printed joints to form an unnecessarily floppy frame. Doesn’t work yet, not enough structural integrity.
introduction to contact image sensors like from scanners #hardware #video #toread
#EEVblog teardown of a CCD scanner array from a fax machine. He mentions at about 2’20" that people complain when he pronounces “LEDs” as [lɛdz]. Most of the video is microscope footage. There’s a massive array of tiny lenses which he describes as “kind of like an optical zebra strip”, which seems fair, but it turns out it’s called a “rod lens array”; the lenses are something like ten times as thick (5mm) as they are wide (0.5mm?), so presumably what they’re doing is putting a virtual image of the page very close to, or on, the CCD itself. The 25 or so transistors attached to each pixel of the sensor array makes me wonder if it’s maybe actually a CMOS sensor rather than a CCD, since a CCD can serve as its own shift register. #hardware #video #optics #electronics
#EEVblog photocopier teardown #hardware #hoarding #video #toread
salvaging printer parts #hoarding #video. No words, by Salvadore Tartaglia; full video on his Italian channel. He disassembles a Brother all-in-one scanner/printer, but doesn’t really explain what the parts are for. There’s an optical encoder wheel on the paper feed and a belt driving the carriage from a DC motor, which I think has an optical encoder tape that isn't shown clearly. He thoughtlessly rips off the optical encoder wheel and discards it, apparently unaware of its significance.
“this #RISC-V cyberdeck is not for you.” Sponsored product review #video on the Sipeed Lichee Console 4A which can play YouTube in 480p and has gigabit Ethernet, despite being ten times slower than tiny Intel netbooks. 1280×720. Clitmouse. 600 grams. Touchscreen. Webcam. You can type on it faster than an iPad. Quad-core #T-Head C910 processor (TH1520), underclocked to 1.5GHz. 4.4 gigaflops. GPU is Imagination PowerVR, with performance similar to the Raspberry Pi 4.
generating 100Vdc with a Cockcroft–Walton voltage multiplier. #Video has a very nice 3-D display of the schematic where voltage is represented as elevation! Unfortunately very introductory.
#SunShine accidentally made an e-bike by #3D-printing; apparently he just drives the rear rim with a 3-D printed helical gear driven by a drone motor held in place with some T-slot aluminum extrusions. #bicycles #video
#LudicScience #video on useful parts from an old printer, a Samsung laser. Kind of clueless. It makes me cringe seeing him poke the first-surface mirror with a screwdriver, and he erroneously claims the mirror-spinning motor is a stepper. #hoarding
switched reluctance motors #video of nearly just a talking head. Though #Akio does spin his motor by hand a bit
#bootstrapping a plasma cutting machine from scrap (if your scrap includes an old welder and a humongous full-bridge rectifier etc.) #video of this Italian guy kludging all kinds of crazy things together, building a giant high-current inductor, etc. Also he starts with a plasma torch.