#CodysLab #video on #bootstrapping H₂SO₄ #materials with the chamber process. He gets 20mℓ. #scouting
#ScrapScience #video on #bootstrapping HNO₃ #materials from KNO₃ using a terracotta flowerpot as an #electrolysis membrane with the drainage hole plugged with silicone, incorrectly described as a “semipermeable membrane”, in an HDPE container made from cutting the bottom off a plastic milk bottle. Copper cathode made from thick wire, graphite anode made from some round graphite bars. 100g KNO₃, unknown quantity of water (maybe 500mℓ), some distilled water added to the anode chamber. Initially he gets 90mA at 7.5V (=80Ω), but pretty soon that rises to 630mA (≈12Ω), and he limited the current to 1.02A. No hydrogen is generated at the cathode, surprising him, but he says it’s because the nitrate ions are reduced to ammonium. After about a day the graphite anode has been completely eaten, which makes me think it wasn’t really graphite, but like carbon arc gouging electrodes or something. The cathode compartment ended up being very basic and smelling very strongly of ammonia, so he made ammonia too. He says his crude titration (not shown) tests the acid at 0.7 molar, which apparently isn’t enough to attack copper, so he boils it with some copper in it, eventually dissolving the copper after boiling it down 4×. While this method does seem to work, it seems a little bit like a method of making an engine starting with only a car — the cheapest way to get KNO₃ is by neutralizing HNO₃ with KOH. He also thinks it “isn’t good enough to be practical” because of how dilute the product is.
"Functional Print Friday" #video channel on #3D-printing functional parts
the #Functional-Print-Friday #3D-printing website, with things like machine feet, tachometers, dust pickups, etc.
#video on #3D-printing for #manufacturing #electronics #hardware with the Micronics SLS nylon printer #toread #Krasnow
#video #toread on #3D-printing “viral” tools “so you don’t have to” #manufacturing
#video from 9 months ago on flat-pack waxed cardboard drone #weaponry in #Ukraine “destroying Russian jets”; the airfoils and the rest of the bodies are assembled with rubber bands and tape and can be repaired with a hot glue gun, cardboard, and tape. Looks like there are some wooden rails (dowels?) for mounting the airfoils. Mainly powered by a single #brushless motor and propeller. Brands printed on the body are “Tanglewood Group Ltd.”, “SYPAQ Australia” (who exhibited it at a military trade show this year), and “CORVO precision payload delivery system” ("PPDS"). There’s what look like laser-cut balsa or other hardwood spars in the kit, at least in some cases plywood. SYPAQ’s Michael Partridge is quoted as saying a laptop allows you to “mission plan and launch” it, so presumably it’s not FPV, though FPV seems to be the main approach used these days. “About a shoebox size [unassembled], can carry roughly three kilos. (...) we've delivered over 600 of the PPDS into Ukraine.” Has been supplying “100 of these every month since March”. Mentions a strike at an airbase at Kursk destroying “five fighter jets, a missile launcher, and an air defense system,” then another attack on a Russian site a few days later destroying two cargo planes, also probably with these cardboard drones. #Pricing quoted at AU$5000 per drone. #Slaughterbots #flying
another #video #toread on #PPDS #Slaughterbots #weaponry in #Ukraine #flying
a #video about anti-drone #weaponry being supplied to #Ukraine, the Australian "Slinger" system by “Electro Optic Systems”, which turns out to be a truck-mounted single-barrel machine gun with automatic targeting via image processing, using “the tracking (...) the stabilization algorithms we’ve used to develop for deep space tracking”. Ten were to be delivered by the end of 02023. #Pricing “less than under one million US dollars”. #Australia #politics
#video #toread about an #energy-storage “revolution” seems unpromising due to a CSP #solar thumbnail image. #energy
another #video about attempting #bootstrapping H₂SO₄ from sulfur #materials #scouting #toread
#video from November on diy #drones and #weaponry in #Ukraine, in the drone labs. Largely talking-head footage though. Claims that they gave Ukraine an “edge” that “leveled the playing field”. Mentions friends of soldiers in Ukraine organizing fundraisers on Instagram. Mentions that they’re using “signal booster drones” to counter jamming, and an SBIR for “a lethal payload capability that can be deployed on a small unmanned aerial system (sUAS)”. A pretty reasonable #introduction if you don’t know anything.
#video about #flying the amateur rocket “DIAMOND-X” with waypoints. Arduino, it looks like, with an SD card and an RS422 bus onboard, and servoed tailfins. But his “waypoints” are up in the air near the launch site, not far away on the ground. Largely made with #3D-printing; he regrets having made the parachute connection with carbon-fiber-filled PLA instead of nylon. No code shared, sadly.
#video about #bootstrapping H₂SO₄ from alabaster #materials #scouting labeled as “satire”. He’s going using washing soda for this, which initially made me think it actually was satire, but thinking about it more, it sort of makes sense: calcite is far less water-soluble than alabaster (and he gets something like 50% yield on the calcite, proving it’s calcite with vinegar). But then don’t we just get sodium sulfate (already very useful for #energy-storage phase-change materials, but not the objective)? A water-soluble sulfate is progress, I guess. He converted most of his bicarb into washing soda first, but that seems like an unnecessary step, just convenient to reduce foaming. Then he electrolyzes it at 13.12 volts and 220mA in a hot-glued-together two-chamber cell with some kind of membrane or salt bridge in the middle, using a postage-stamp-sized iron anode (!!) in the chamber of initially almost pure water and a copper chain for the cathode. His objective with the iron anode is to precipitate out the remaining carbonate. Because the current is going up, he infers that soluble iron sulfate is being formed, although sodium sulfate leaking through his salt bridge (?) would be an alternative explanation. After five hours there was a lot of green/black sludge in the anode chamber; from the greenness he infers that the iron has precipitated all the carbonate. Then he runs it through a second electrolysis using a graphite anode, which nevertheless dissolved (I feel that lead would be a better ghetto choice) and electroplated his copper with iron, which is surprising given the presumably low pH. Then he puts it under UV light in a tiny aluminum-foil chamber, which he says is to ensure no remaining SO₃ molecules. No pH or specific gravity measurement.
#NurdRage #video on #bootstrapping H₂SO₄ from oxalic acid (dihydrate) and ferrous sulfate (heptahydrate), and the sun, with 46–67% yield. It’s very surprising to me that this precipitates iron oxalate. He boiled down the resulting acid until the remaining sulfate started to crystallize, then distilled it to 70% of nice, colorless acid. Using more oxalic acid he got 57% yield, and by leaving the defecation beaker in the sun for eight hours to reduce ferric ions, releasing CO₂, boosting the yield to 67%. An attempt with MgSO₄ only gave 2% yield. An attempt with blue vitriol generated a precipitate too fine to filter (maybe because he added the oxalic acid too fast). He says it even works for HNO₃. #materials #scouting
#BrandonMitchell #video footage from Donbas of #Ukraine FPV drone pilots #flying a small ducted-fan quadcopter in the house, then showing off a larger non-kamikaze quadcopter US$700 “Lucky Strikes” drone which apparently drops NATO and Polish grenades. Then they show multiple workshops and weapons including with improvised contact fuzes and tailfins (made by #3D-printing in some cases) installed on these grenades. The famous fragmentation sleeves on RPGs are also shown. They even seem to have a HEAT anti-tank warhead rigged up with 3-D printed tailfins to drop from quadcopters onto tanks. “FPVs are very effective against [sic] destroying armor. (...) NATO munitions are difficult to convert. So many safety mechanisms.” Footage of drone making. #3D-printing around the clock. Also shows FPV-driven remote-controlled cars for laying mines, with wheels and wheelbase similar to a four-wheeled push lawnmower. The radio signals still seem to be direct rather than relayed. Mentions a friend of his who nearly got killed three times because she didn’t know she needed to “anonymize” her Mavic drone (apparently something you have to do in these workshops). Lots of discussion of logistics, timescales, repair pipelines, parts shortages. He says, “We're losing the war. It's not lost, it’s far from lost, (...)”. Lots of discussion of how to raise funds on social media for the war. #weaponry
#video on #Godot multiplayer that’s not by BatteryAcidDev. #toread
#video #toread of #flying over a landfill in an ultralight paramotor
#video on “impedance reflection” in transistors, a technique for easily calculating input and output impedance. But it comes down to just multiplying your emitter resistor by β, or dividing the impedance seen by the base by β to get the impedance seen at the emitter if that’s what you want. He does eventually explain why. Very slow-paced lecture by #AaronDanner, but informative. #electronics
#video of #Ukraine Azov Brigade footage about how they captured a Russian trench fortification in the middle of a forest near the Donetsk/Luhansk border
#video of a beautiful FPV drone flight in a park
#video of ground-based #Slaughterbots in #Ukraine (D-21-11) looks like a slow-moving four-wheeler ATV. The presenter calls it “their drone” and a “UGV”. Ukrainian design. Allen bolts, lots of laser-cut (?) steel plate. The machine gun is mounted on shock absorbers (something like McPherson struts, with springs around what looks like a ground steel piston, but I think it’s actually just sliding through greased bushings). The cut metal plates, which have weight-reduction cutouts, are bent and intermittently welded onto structural steel tubing to form the frame. No visible ribs, so they probably aren’t pressed, just cut and bent in a brake. Lots and lots and lots of screws, probably optimized for field hackability and repairs. There’s a ripcord, but not for pull-starting the engine. About the size of a riding lawnmower or golf cart, and about as fast in what they show here. It can carry about 4–6 people when the machine gun isn’t mounted, or one person in a lying-down position, tied down with bungee cords to built-in D-ring tiedown spots. It’s electric with 15km of battery; the battery does have ribs. Two or three cameras on both the front and the back surrounded by near-infrared LEDs. Two 1.5-meter-long things at the back that seem to be large whip antennas. Turns in place like a tank rather than by turning the wheels; there seems to be a chain drive to each wheel, protected by a metal chain guard. It seems you can drive it from a laptop with a game controller or from a purpose-built FPV remote controller.
#video on an approaching #EU ban on pure basic #materials; he’s diluting them to keep them legal
#video from #Ukraine of an FPV pilot repeatedly buzzing a squad of soldiers #flying #weaponry
#video of Russian soldiers on a speedboat on the Dnieper shooting down a #Ukraine FPV drone #flying after them, maybe with a rifle. A second drone covers the boat with shrapnel from an air blast, killing four of the seven soldiers; the other two, unable to control the boat, jump into the water as a third drone arrives, killing them as well. A seventh remains unaccounted for. A fourth FPV drone blows up the boat. #weaponry
#video on a zip gun, improvised #weaponry used in the 01950s made out of plumbing fittings. Supposedly legal in the #USA.
#video of an Irish FPV pilot from South Side Dublin, nicknamed “Irishman”, with Ukrainian parents, in the “Terra” FPV unit of the third “storm brigade”, #flying drones into Russian D-30 (122mm howitzer, perhaps US$3 million) and D-20 #weaponry in #Ukraine from what seems to be a stone vaulted basement; they said they knew the first one wasn’t a decoy from observing artillery fire the day before, though later they identified a decoy from the FPV video. They destroy a whole artillery unit (six artillery pieces, or maybe four, or two, it varies). He came in through the Internatsionali Ligion (my transcription). Mostly interviews with the four soldiers in the unit. A Russian FPV drone finds the bunker where they’re piloting from but doesn’t find them. They’re uploading the videos to raise money for more drones on social media.
#video #toread about #bootstrapping woodworking tools
#video by #Segerman about a maze (“dodecahedral holonomy”) where the “rook” you move around has arms sticking out so that which edges it can traverse depends on its state of rotation, which varies when it travels a closed circuit, providing a 120-vertex graph. Generatively designed with Grasshopper after his Python code spent several hours designing the maze.
#video #toread about #3D-printing #mechanical parts with 25% glass filled filament
#video from two weeks ago of #Ukraine kamikaze FPV #flying #weaponry killing Russian soldiers. Fundraising video for “Terra”. The first drone they fly is a hexcopter, maybe a surveillance drone; the first kamikaze they show taking off with a metal cylinder zip-tied to its bottom is a quadcopter whose arms seem to be round tubes, maybe GFRP. It's using three-bladed propellers and has a fairly oversized battery pack on top. The Russian targets, which they refer to as “cockroaches” (like in Rwanda!), are holding a previously Ukrainian trench; the first drone blows up in the trench, though the actual death is censored on YouTube. The squad is operating the drones from a concrete-roofed brick basement close to the front lines. The second and third drones are used to disable what looks like a turtle-tank-armored IFV, and the fourth kills a Russian soldier in the trench who is attempting to shoot it down with what looks like a shotgun. The fifth kamikaze drone launches carrying what looks like an RPG, which is zip-tied to it and thus unable to fly on its own; not sure if it has a shrapnel belt. It’s pointed horizontally, so it wouldn’t be useful for HEAT; instead they detonate it over the head of a fleeing Russian infantryman, killing him. A sixth kills another fleeing infantryman with a fragmentation charge, and a seventh is launched carrying another RPG to pursue the last infantryman, but opportunistically attacks a “Bukhanka” vehicle poorly hidden inside a hangar instead. An eighth is used to set fire to the building some other troops fled into. Because some other troops fled into a hangar, they launch a heavier hexcopter kamikaze drone with a larger charge (4 kg of PVV-7, later described as 3 kg), whose arms are carbon-fiber-reinforced tubes.
#video of #Ukraine bomb-dropping #flying #weaponry killing Russian soldiers. Fundraising video for “Terra”. In Ukrainian with English subtitles.
#video of disassembling a BM-23 Russian tungsten-core fin-stabilized APDS tank cartridge from 01985, showing 8.5kg of nitrocellulose propellant extruded in the form of thin tubes, packed into the cartridge. Demonstrates how it burns when ignited with a cigarette lighter, and shows the wax-paper phlegmatizing liner. Knocks apart the sabot with an axe. The sabot is small and toward the front of the dart, relying on copper buttons around the tailfins to center the tail in the barrel, while many other APDS designs use a longer sabot. #weaponry
#video #toread by #Tony-Soares about the “urban Anasazi” #ceramics firing technique
#video #toread where #USA drone operator describes his experience #flying #weaponry, specifically the Puma drone
in April 02022 #DJI quit Russia and #Ukraine over the widespread use of the Mavic as improvised #flying #weaponry. Supposedly also Starlink was crucial to streaming FPV footage from drone crews to artillery crews until March 02023, at which point they blocked their service in Russian-occupied territory, over water, and at speeds over 100km/hour, claiming that the purpose of providing Starlink was humanitarian, not military. #video
#video #toread on the cheapest MIG welder in the world. #mechanical #manufacturing
#video on #3D-printing a #flying radio-controlled model Orca tricopter (three ducted fans) from Command & Conquer with #topology-optimization and nylon powder “multijet fusion” which sounds like it doesn’t involve any jets at all. No notes on the electronics or software.
#video about #3D-printing a whole #flying drone, “even the motors”, using 3 kg of filament, but evidently they’re wound with regular copper wire and using steel cartridge ball bearings and steel nuts and bolts and, originally, a steel 8mm shaft and collar, which he replaced with (brass?) heat-stake inserts and a precision-ground steel shoulder bolt. The motor’s magnetic core is, however, 3D-printed using “magnetic PLA”. He’s also using (rare-earth?) permanent magnets. The dovetailed arms (evidently designed using #topology-optimization, and vastly overspecced) are held on with a very interesting plastic twistlock design. He measures the thrust as ≈3kg of weight (≈30N) using a US$8 load cell from Amazon, but the motor took 2½ seconds to spin up to full thrust rather than the 800ms for a much smaller comparable-thrust off-the shelf all-metal type. By #Michael-Rechtin. #mechanical #manufacturing
#AvE #video about Samsung flip phones but mostly about Gorilla #glass. Mostly just a bunch of handwaving. But then he does a teardown of a flexible plastic OLED screen that folds in half, so it’s all good.
#Godot 4 multiplayer #tutorial #video #toread not by BatteryAcidDev
another #Godot 4 multiplayer #tutorial #video #toread not by BatteryAcidDev
#video about FPV drone #weaponry in #Ukraine, describing the tradeoffs of things like analog vs. digital video. Lots more #3D-printing on view here.
#video about #manufacturing #aluminum-air #batteries with dual electrolytes: potassium hydroxide and 50% H₂SO₄, separated by a membrane, to get a higher voltage, over 2 volts. Uses “activated carbon felt” (??) for the air electrode. With a single electrolyte he gets 1.56V. He suggests bleach as an alternative alkaline electrolyte and vinegar as an alternative acid. He uses paper towels to hold the electrolytes in place. For “some short testing” he uses baking paper as the membrane, but of course it won’t last long in that environment! He suggests Nafion as the only viable membrane option. His postage-stamp-sized test cell gets 2.2 volts and can light an LED. He adds MnO₂ to his graphite electrode as, I think, a depolarizer, boosting the cell to 2.5V. (Maybe it’s an actual electrolyte material, though?). For whatever reason he never measures its short-circuit current, except for showing that the LED lights and doesn’t immediately burn out, so the battery presumably has on the order of 100Ω of equivalent resistance. Finally he builds a version of the battery with a salt bridge instead of a membrane, but using zinc rather than aluminum. Surprisingly the salt-bridge version is also able to light the LED, despite presumably having much higher ESR. #energy #electrolysis
#video about #manufacturing #aluminum-air #batteries with either KOH or NaCl electrolytes. #energy #electrolysis Unfortunately “members only”.