I created another very interesting gearbox design for my micro motor project, a split ring compound planetary gearbox. This has two stages of planetary gears, with the planets merged together (they have to be co-axail). The output ratio is close to the first stage output as well as the difference remainder of teeth between the two rings. The more teeth you have or the lower the difference between the two teeth are, the higher the ratio is. The math is a little bit tricky to work out though. You can get a 3000:1 ratio in a really small form factor! My current gearbox is a ~75:1 . Github for my motors project: github.com/techy-robot/Mighty-Micro-Motors. Onshape link to this version: cad.onshape.com/documents/c861ec30af8169cf9c14bd7f/w/e538486c85e6a5fe77cd1d33/m/06649b39967f5e540a56afb8/e/c076bfebf996b33c466ae250
I finished making some quick little fixes to my cycloidal gearbox, to adapt to the new motor pcbs I designed. I have a flex cable magnetic encoder up top, and a 11mm diameter motor driver pcb on the bottom. The gearbox motion system itself has also changed a little bit, going from 3 screws and 3 roller pins, to just 3 screws total (they are acting as the roller pins) The gearbox height has decreased 6mm vertically too (magnet taking up less space)! Github: github.com/techy-robot/Mighty-Micro-Motors. Latest commit: github.com/techy-robot/Mighty-Micro-Motors/commit/ef4e956383e01cbf108f42c05102d1eff5ecf448
I finished designing a 2 cell battery charge, monitor and protector for my motor control test board. This is very packed, with the PSU size coming in around 15x45mm (tacked onto the existing MCU board). There is not much space to shrink the design more. Github: github.com/techy-robot/Mighty-Micro-Motors/tree/main
I finished a partial revision of my motor control board. Since the motor driver portion is now on the back of the motor (last scrapbook: hackclub.slack.com/archives/C01504DCLVD/p1724019667262769), I have extra room on the board. I was able to shrink the main design by 10mm on one edge, and I also added pin headers and an FPC connector for the magnetic encoder. The final design will have for motor port connections, but this is still a test board. github.com/techy-robot/Mighty-Micro-Motors/releases/tag/v0.3.0
I finished design a 11mm diameter on-motor driver pcb! Its really small, the 0402 components barely fit with standard 4 layer 0.2mm traces, and I have no clue how problematic heat may or may not be, but I'm trying it! This is for my micro motors project. Github: github.com/techy-robot/Mighty-Micro-Motors. If successful the main board can be much smaller.
Finished a redesign of my little magnetic encoder board! Now its on a flex cable so integrated wiring, making my motor assembly easier. The whole thing is also smaller in diameter. Length is around 75mm. Check out the full motor project here: github.com/techy-robot/Mighty-Micro-Motors
Well I believe I have maxed out my current design iteration of my micro motor gearboxes. Everything is finicky or has already broken, so I am considering this a milestone because from now on I will be redesigning everything. The motor control board no longer is in charge of itself (wires were soldered on to allow an external MCU to control the driver), the magnetic sensor board has been sanded down to be smaller, and just recently pulled a small trace off (Image), and my resin printed gearbox is lackluster, brittle, and super high friction ( Onshape). The only direction from here is up and redesign everything.
I finished designing a cycloidal gearbox in Onshape! This is for my micro motor project, where the goals is to be the size of your thumb. Currently its a bit too big, but I can't shrink the design much further without removing bearings entirely. I have sourced some of the smallest bearings already, so nothing much I can do. The top dome houses a magnetic encoder and magnet, which I can probably shrink. Also, I spent a lot of time on this, probably more than 25 hours so I may have to split up sessions. Github: github.com/techy-robot/Mighty-Micro-Motors. Onshape: cad.onshape.com/documents/c861ec30af8169cf9c14bd7f/w/e538486c85e6a5fe77cd1d33/m/a3c9333dac0244a404873054/e/395711bbc38dcc987be1be1a
I finally got my little motor controller and motor working *smoothly*! I had to rewire a little fix on the driver chip so that all three lowside input pins were pulled to 3.3v. Previously it was two out of three, causing one phase to be skipped. I also had to make some small tweaks to my code, because the order of the initialization matters and I was specifying too much current for the init routine (overloading the motor so it wouldn't move). I was able to tune a PID velocity control loop for the motor as well, using a magnetic encoder as feedback. github.com/techy-robot/Mighty-Micro-Motors
#arcade I finished basic hardware testing of my little motor control PCB! The only thing I haven't tested is the battery charging, since I don't have a suitable battery. Things I have tested:
• Can be powered on without exploding
• 3.3v regulator on the motor chip works (though with a flaw that requires a kickstart to get it going)
• Can be programmed and flash an LED
• Can be clocked to a max 64mhz
• Power mosfet switching works on the charger
• Can communicate over SPI, UART and the debug interface
Next phase involves getting a motor to spin, and designing a gearbox. Check out my project here: github.com/techy-robot/Mighty-Micro-Motors
#arcade I helped out @PonderSlime with a game feature! The walk animation no longer looks like the player is gliding over the surface, now the walk animation and the player movement is synced together so the player looks like it is actually walking with traction! Merged github pull request: github.com/PonderSlime/Planet-Earth-Stranded/pull/2
#arcade I designed and assembled a motor control PCB for small brushless motors, with integrated battery charging! I did a power test and nothing blew up, I have yet to program anything. I also have a little magnetic encoder pcb. Checkout the github here: github.com/techy-robot/Mighty-Micro-Motors
