#TPAI #video #toread about #manufacturing his #CNC plasma cutter
on 02024-07-06#TPAI #video #manufacturing a #CNC milling machine from mostly scrap metal. He’s using the crankshaft timing pulley from a VW Golf 2 1.8 8V engine to couple his head-sized NEMA 34 junkyard stepper motors to his junkyard Acme leadscrews for the Y-axis, because the pulleys cost US$5. The pulleys have a size-L toothed belt with a 14.5mm bore and four M8 threads around the outside, one offset by 5°. He drills the pulleys out larger to fit onto the leadscrew shafts, then makes an aluminum driving adapter to bolt the pulleys to so he can couple them to the shaft. For coupling the other pulleys to the 14mm stepper shafts, he also drilled them out bigger, then made a brass tube adaptor to which the pulleys are held with three setscrews. For his X axis he’s using a junkyard ballscrew. He mentions that ATX power supply #electronics have their -12V rail connected to their enclosures and to the ground wire, which I didn’t think was correct, but anyway he removed that connection in order to be able to use four of them in series to get 48V. For sheet metal bending without a brake, he clamped his sheet metal to the edge of a table and whaled on it with a 4×4 board. He demonstrates the use of his existing homemade CNC plasma cutter. Finally he mounts a 2000-watt wood router onto the large gantry he’s built and uses it to route some beech butcher block and some aluminum plate, and even 4mm-deep grooves in steel (using a tungsten carbide bit). He mentions the need to minimize the number of piercing operations for CNC plasma cutting because of how they wear out the nozzle quickly, a consideration I hadn’t realized.
on 02024-07-06#TPAI #video on #hoarding high-power junkyard stuff for #jugaad.
Loosely defined; Gerolf’s first “exciting find” is a 35kg transformer with a 200-amp secondary that’s only 5kVA because it’s 50Hz. Seems to be of E-I construction, so it could be a good source of electrical steel, not to mention high-ampacity copper, although his first step is to cut through the 6-kilogram 200-amp secondary with an angle grinder. His objective seems to be to make a kiloamp source for heavy welding, although I’d think a 200-amp secondary would be fine for that. He can’t usefully ohm out the primary because he doesn’t know about Kelvin connections, but he does succeed by measuring the inductances instead. He compares it to a couple of microwave-oven transformers, removing their secondaries and magnetic shunts to replace them with welding cables. 2½ turns on the small MOT can reach 395 amps. The larger MOT (also 2½ turns) reaches 649A. Another transformer he had lying around reaches 666A. 3½ turns on the 5kVA transformer exceeds 1kA, which is the limit of his clamp meter, so he got another one which measured 1200A.
This seems like high current but not high power; an inline-6 Mazda CX-90 is, by contrast, 16.6 horsepower, or 12.3kW, more than twice the rated power of this transformer, and presumably its actual output power is even less when you short-circuit its output through a wrench like this.
He also picked up a handheld spot welder (Dalex-Werke, 380VAC input, 9.2 kg, and various nameplate power ratings I don’t understand including 2.4, 6.1, 10, 2, and 20 kilowatts; I guess 7500 amps is the secondary short-circuit current and should not be multiplied by the nominal 2.3 volt output rating to get 20 kilowatts). He does get it to make some spot welds on razor blades.
He also found a component stereo system (Grundig RT 40 M tuner, Grundig SV 40 M amp, and Dual 1219 turntable) with a fake wooden façade; the tuner capacitor in the radio wasn’t even stuck, and both the radio and the amp from 01967 worked fine! He painted over the ugly fake woodgrain. He had to melt polymerized lubricant off the record player’s speed selection #mechanisms with a heat gun, then scrub it off with WD-40 and steel wool. Also the power switch doesn’t work, and he had to replace the pickup and the center pin. He explains the stroboscopic tachometer at 28'10".
on 02024-05-17#TPAI #video on #hoarding junkyard machinery #toread
on 02024-05-15#TPAI on boost converters #hardware #video with a demo of a manually-operated one. He mentions the TL494, which he “doesn’t recommend as a beginner’s project”, for which he recommends the LT1070, which he then builds a 20V laptop charger around. For his water-wheel power supply, he uses the “Delon circuit”, a full-wave rectifying voltage doubler with five components. Then he uses it to charge his cellphone and a gel cell from a stream. #electronics
on 02024-04-06#TPAI salvaging parts from printers and scanners to reuse. #hoarding #bootstrapping #video very slow paced. From an HP inkjet/scanner combo he salvages a paper cone speaker, a switchmode power supply, the paper feed photointerruptor optical encoder (with a bit of abuse to the transparent plastic disc), the paper feed dc motor, the carriage dc motor (including its wiring harness), the precision ground carriage rails, the carriage drive toothed belt, the photointerruptor tape from the carriage encoder, numerous springs, the sump pump dc motor with its photointerruptor encoder, lots of plastic gears, the paper feed platen axle and another paper feed roller axle, the scanner bed glass, the scanner drive stepper motor, the CCFL power supply, the cold-cathode fluorescent lamp itself, three mirror-glass strips, and the scanner lens. It looks like he was going to make a followup video but never did (this was ten years ago).
on 02024-04-03#TPAI salvaging parts from dishwashers to reuse. The interior is stainless! And he salvages thermal cutouts, water heating elements, a 16-amp 240-volt relay, a capacitor, the power switch, a pressure switch, a shaded-pole induction fan, a 30-watt “extrusion pump” to move water, some smaller relays, a bunch of power electronics (including seven triacs), a rotary switch, an EEPROM, some opamps, some darlington array drivers, a thermistor encapsulated in stainless steel, an electromechanical valve (“Aquastop”), a styrofoam float microswitch, the giant induction-motor-driven dishwasher circulating pump (the single-phase type with a start capacitor), and a Mitsubishi M38027M8 8-bit microcontroller. #hoarding #bootstrapping #video #scouting
on 02024-04-03