• More magnets

    mulcmu • 06/30/2024 at 15:53 • 0 comments

    Added 8 more holes to disc for more magnets.  Still 4 poles alternating 3 North, 3 South.  Tried some flux consolidating washers one the back side as well.  Some minor improvement in the output voltage, but no where near enough to light a LED.

    Also tried to remove the solder mask above the coils and apply layer of solder on top of the copper to make traces thicker.  Pretty messy and inconsistent.  Not too much left to try without changes to board for better suited coils.

  • Testing

    mulcmu • 06/26/2024 at 23:23 • 0 comments

    Boards arrived, forgot to check the remove order number option.  Initial testing didn't go so well, no light from the LEDs when spun by hand or with assistance of drill for that matter.  Seem to only get a few tens of mV out from the rectifier.    Added more and bigger magnets to test but no improvement.  Should have added some test pads to the coils.  Might try to hook scope up to see what waveforms look like.

  • Mechanical 2

    mulcmu • 06/22/2024 at 14:00 • 0 comments

    Got the clearance right to hold the magnets in place and minimum wobble in the shaft.  It's going to be balancing act between getting magnets as close as possible to the PCB and still minimize/prevent rubbing.  I ordered a shaft assortment and a few more bearings.  Can drill out the 5mm hole to about 10mm without impacting the traces.  PCBs have shipped but a few more days to wait until they get delivered.

  • Mechanical

    mulcmu • 06/19/2024 at 13:21 • 0 comments

    I had some 2mm ID x 6mm OD x 2.5 mm wide bearings on hand and a 2mm x 8mm shaft that fit.  Designed some 3d printed parts around these to hold the magnets.  Magnets were 6mm x 1.5mm that were on hand as well.  Drilled a 5mm hole in scrap PCB to test, slightly skewed.  Seems to spin okay with just bearing and shaft but it's hard to hold.   Test PCB was 100mm x 60mm vs 90mm x 50mm.  Spun nicely when held in vice.  Clearances were a bit loose on first batch of 3d printed parts.  Magnets slipped out and shaft bore was a bit loose.  Added the jolly wrencher logo for some HAD bling.

  • PCB

    mulcmu • 06/19/2024 at 12:46 • 0 comments

    PCB design used the kimotor (https://github.com/cooked/kimotor) KiCad plugin to make quick work of coil layout to fit in the card outline.  Going cheap with 2 layer board.  The rest is just rectifier and LEDs.  Made another board iteration with a reed switch footprints to maybe switch the LEDs on and off with the magnets...

    Boards ordered and will hopefully arrive with a few days before contest entry deadline