The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Author: Ed

  • HT GPS+Voice Circuitry: Bare PCB

    Drilling the PCB went fine, as did the etching & silver plating:

    PCB with edge wrap - front
    PCB with edge wrap – front

    The rear side has a fine ground plane:

    PCB with edge wrap - rear
    PCB with edge wrap – rear

    The small spots scattered over the rear mark vias that stitch the front and back planes together; lacking plated-through holes, I solder nippets of 24 AWG wires to both sides. The wrinkly edge comes from solder on the copper foil binding the entire perimeter.

    While I have no hard evidence that all of the fuss & bother matters, the most recent version of this circuit is the quietest yet: the machine noise from the TinyTrak3+ that plagued the first iteration has pretty much vanished.

    I’ll grant you that the silver plating doesn’t look very silvery in these pix, but it’s quite different from the bare copper in person. Here’s the front just after rubbing it in with a vigorous circular motion:

    HT-GPS PCB - raw plated - top
    HT-GPS PCB – raw plated – top

  • HT GPS+Voice Case: Latch Bar

    This iteration of the case latch has slightly larger brass tubing on the ends, hand filed to match the case angle:

    Shaping case latch bar
    Shaping case latch bar

    It’s pretty much the same process described there and is why I set up that slitting saw arbor for the next time.

    The final result looks pretty good:

    HT-GPS Case - Latch plate detail
    HT-GPS Case – Latch plate detail

    Those tubing snippets really must be two different lengths: the bar slides to the right (in that picture) to release the case, so:

    • The short tube and the notch must fit into the space between the edge of the case and the release slot.
    • The long tube slides outward, with a mark to indicate when the notches align with the release slots.

    In principle, you could slide the bar until the shorter tube jams against the latch ramp on the radio, but this case (plus the end caps) turned out to be exactly as long as the distance available and is a rather snug press fit. The next version will be 0.75 mm shorter and should fit better, although snug is good in this situation.

  • Specialty Duct Tape

    Saw this at the local Jo-Anne Fabric and got it on sale:

    Penguin Duck Tape - detail
    Penguin Duck Tape – detail

    Kinda classes up the joint, doesn’t it?

    Penguin Duck Tape - ready for action
    Penguin Duck Tape – ready for action

    Yes, it’s really Duck Tape …

  • Harvestman Colloquium

    For some reason known only to them, one of our kitchen windows attracted a congregation of harvestmen for several mornings in a row:

    Harvestmen on window screen
    Harvestmen on window screen

    A trio appeared on the end of a honeysuckle tendril that’s making its way up a pillar supporting the roof over the patio:

    Harvestmen on honeysuckle
    Harvestmen on honeysuckle

    It certainly appears they’re deep in discussion…

    They’re harmless and they’re outside, so we let them be!

  • Panasonic CR123A Lithium Cell Capacity

    Picked up 25 Panasonic CR123A (more properly, CR17345) cells from the usual eBay supplier and put one to the test:

    Panasonic CR123A _ CR17345
    Panasonic CR123A _ CR17345

    Somewhat to my surprise, it delivers pretty nearly its full rated capacity at 400 mA discharge. It’d do even better at its 20 mA (!) rated current, of course, but I wasn’t up for a lengthy test…

    Yes, the nominal capacity spec is at 20 mA (C/77) discharge: one LED worth of current. Even the pulsed spec is only 900 mA at 10% over 30 seconds, which says a flashlight really puts the screws to the poor things…

  • SPD Bicycle Cleats: Wearout Thereof

    Mary decided her cycling shoes were worn out after about four years and maybe 8000 miles. Walking with cleated shoes doesn’t work well (no, we don’t bother with cleat covers), but they’ve seen a few miles of pavement, too:

    Worn SPD cleat in cycling shoe
    Worn SPD cleat in cycling shoe

    A closeup shows that the surface of the old cleat really has worn away:

    SPD cleats - new and worn
    SPD cleats – new and worn

    The rear tang is mostly there:

    SPD cleats - rear tang
    SPD cleats – rear tang

    But the front tang is mostly gone:

    SPD cleats - front tang
    SPD cleats – front tang

    New shoes, new cleats, new pedals… we’re still tuning for best fit.

  • Wouxun HT GPS+Voice Case: Colors!

    Rather than print another green case, the new, improved case has orange end caps:

    HT-GPS Case - End caps on build plate
    HT-GPS Case – End caps on build plate

    And a blue shell that’s a bit easier on the eye:

    HT-GPS Case - Shell on build platform
    HT-GPS Case – Shell on build platform

    Put ’em together and it certainly looks peppy, doesn’t it?

    HT-GPS Case - trial fit
    HT-GPS Case – trial fit

    That’s a trial fit with nothing inside, of course.

    Next step: circuitry!