#GreatScott #video on #FOC #control #electronics for #brushless #motors #toread
on 02026-08-25#optics #precision #manufacturing #video on making things flat. Like, optically flat: 50nm peak to valley, 1nm RMS. With a “planetary polisher” or “continuous pitch polisher”, which rotates a huge pitch lap underneath a “bruiser plate,” ideally made of something like Zerodur, carrying the blank or blanks. Helpfully explains that the grooves in the pitch lap prevent aquaplaning, just like the grooves in a car tire #tread. In order to avoid having to run his machine continuously, using a many-pole #brushless motor obtained from #hoarding a washing machine, he uses a very high-viscosity pitch (100× more than normal) in a very thin layer, which he initially flattens with a granite plate for 15–20'. His pitch lap is supported on five rollerblade wheels, and he controls motor speed with a VFD. Matching the angular velocity of the lap and the blank results in constant grinding across the surface.
on 02025-12-17#video about controlling #motors with #FOC (field-oriented control) and using them as dials. Using SimpleFOCproject to do PWM microstepping of #brushless motors to get smooth motion down to zero velocity? Also steppers. The BLDCMotor constructor argument is the number of pole pairs, which he got wrong at first. But he’s cheating by using an AS5600 I²C magnetic encoder! This has the very interesting #UX idea of simulating mechanical detents by using the motor for haptic feedback on a knob. #electronics
on 02025-10-17#video #toread on using stepper #motors instead of #brushless motors for #3D-printing
on 02025-10-16a little RS-485 #brushless servomotor
on 02024-11-05#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
on 02024-06-25#video on salvaging the mirror #brushless motor from a laser printer. #hoarding by #Zafer-Yildiz. I expect disappointment from watching a video of his previously. Jesus fuck, he’s touching the first-surface mirrors with his fingers. Which are dirty. ALL OF THEM. Good tip on identifying power rails from the polarization of a smoothing cap. By grounding different signal lines on the connector through a 1kΩ resistor he gets it to spin up! But shows no waveforms. He gets it to spin faster by overvolting it (initially 12V from his lab supply.) By feeding in a varying-frequency sine wave on a control pin he also gets different speeds. Not that bad a video for 5 minutes I guess.
on 02024-06-08build a drone engine from an old hard drive #video #hoarding a two-platter 120GB 7200 rpm Seagate Barracuda specifically. By #Zafer-Yildiz. Normally I’d assume the spindle motor was too low-powered to be useful this way, since they consume about a watt in normal operation, and quadcopters usually use several hundred watts per motor. He solders a “Simonk30A” ESC to the spindle motor and attaches the rotor from a computer cooling fan, which was unsurprisingly also a #brushless motor, with a bit of gelling superglue. He supplies the ESC with 12 volts, which is probably what the motor originally used. Even before he adds reflective tape to one of the fan blades, it seems to be poorly balanced and has a lot of vibration, which is probably not what the motor’s precision bearings are optimized for. Apparently he’s driving the fan at 6600–7900rpm. No force measurements, no temperature measurements, no power measurements, nothing. Zafer, I am disappoint.
on 02024-04-06salvaging things from an old computer detailed #electronics dissection of a CD-ROM drive, extracting the head, the plastic gears, the ground dowel rail, the stepper leadscrew, and the brushless spindle. He hooks the spindle up to a power supply and sticks a propeller on it. Without a propeller he gets it up to 16000 rpm according to his laser tachometer. From the computer he also recovers a CPU cooler, the ATX power supply, a piezo buzzer, a power LED, and a floppy drive. He removes the connectors from the power supply but fails to look up what some of the wires are for, although he does somehow look up the use of the “turn on” green wire. Amusingly, his test for the 12-volt line was the same as mine: a car headlamp bulb. He charges a couple of 1.5-volt rechargeable AA cells (1100mAh) with the 3.3 to 5 volt difference, which I guess is pretty safe for Ni-Cd or NiMH cells. But then he inadvisably charges some bare lithium-ion cells with the 5-volt line dropped down to 4.4 volts with a series diode. Then he hooks up a 22-amp 12-volt DC motor to the 12-volt lines with a larger propeller, and then a 24-volt brushless motor (maybe salvaged from a printer) across the ±12V lines. Then he runs a 36-volt ebike motor from the ±12V lines. Then he charges a 12-volt lead-acid battery from the -3.3V and +12V lines with a diode to drop the voltage a bit. From the floppy drive he salvages the #brushless motor but can’t figure out how to use its driver board, so he hooks it up to an external ESC, the same one he used to drive the CD-ROM spindle motor. In order to desolder its windings he turns down his old soldering iron tip on a lathe. (I don’t remember having previously seen someone heatshrink tubing with a soldering iron.) The floppy drive motor goes 6000 rpm at 17V and 14000 rpm at 19V. #hoarding product-shill #video #hardware
on 02024-04-05Oskar Weigl’s #brushless DC motor #hardware controller ODrive, which is nearing completion; the firmware is X11-licensed and is on Github
on 02017-02-23