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.

Category: Machine Shop

Mechanical widgetry

  • 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 …

  • 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!

  • Storing Sherline CNC Mill Leadscrews

    After replacing the Y axis leadscrew, I decided that the X axis leadscrew was in fine shape, because it’s tucked under the table and not exposed to the swarf and grit that fell on the Y axis screw before I installed the bellows. Being that sort of bear, I couldn’t throw out the worn Y axis leadscrew, so I had two rather delicate rods that really needed more protection than a twist of paper.

    So I sawed off a length of 1 inch PVC pipe, faced the ends in the lathe, and added two rubbery endcaps from the heap:

    Sherline leadscrews stored in PVC pipe
    Sherline leadscrews stored in PVC pipe

    That fits neatly into the big box alongside the rotary table, with the bag of assorted nuts so they’re all together.

    Despite what you see there, the screws are wrapped in paper with a bit of oil, so it’s all good.

  • CO2 Capsule Fins: Party Edition

    CO2 capsules with multicolored fins
    CO2 capsules with multicolored fins

    These emerged from some recent printing sessions, where they served to join two successive colors as I changed ABS filaments.

    Whenever I give a talk, these are the last tchotchkes to go. Maybe some festive party fins will help?

  • Primo Comet Aneurysm: Teardown

    So, as you might expect, I couldn’t let the aneurysm on that tire get away without a closer look: had to haul the poor thing out of the trash and dissect it. Here’s what it looked like on the bike:

    Primo Comet Aneurysm - inflated
    Primo Comet Aneurysm – inflated

    The outer rubber has disintegrated and is pulling away from the Kevlar belt underneath, but it’s still holding air!

    Cutting that section out of the tire and flattening it makes things look almost normal:

    Primo Comet Aneurysm - flattened
    Primo Comet Aneurysm – flattened

    Peeling the rubber off the carcass reveals that the body cords have either broken or ripped loose under the belt:

    Primo Comet Aneurysm - peeled
    Primo Comet Aneurysm – peeled

    There was no external damage over that part of the tire and I was wrong about a gash in the Kevlar belt. However, the ends of the belt overlap just above and to the right of my thumb, so perhaps there’s a manufacturing flaw in there somewhere.

    Now it’s in the trash!