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: Oddities

Who’d’a thunk it?

  • Candidate Caravan

    For obscure reasons, the Silly Season brought Sanders, Trump, and Clinton fille to the City of Poughkeepsie within the span of eight days. We know enough to stay far away from such events, but one of the contestants came to us!

    A siren heralded flashing lights off to the left, coming up the hill from the bridge over the Mighty Wappingers Creek:

    Candidate Motorcade - 0463
    Candidate Motorcade – 0463

    The police car jammed to a stop in the middle of the Red Oaks Mill intersection, directly in front of the cars (and bikes) that had just begun moving after the light turned green:

    Candidate Motorcade - 0700
    Candidate Motorcade – 0700

    During the next minute, the officer managed to clear most of the traffic from the left-turn storage lanes perpendicular to us, after which two motorcycle officers led the procession:

    Candidate Motorcade - 5015
    Candidate Motorcade – 5015

    Two ordinary SUVs with flashing light bars followed:

    Candidate Motorcade - 5211
    Candidate Motorcade – 5211

    Two stretched SUVs with side window and marker flashers:

    Candidate Motorcade - 5403
    Candidate Motorcade – 5403

    One blatantly inconspicuous black sedan running dark:

    Candidate Motorcade - 5467
    Candidate Motorcade – 5467

    Two black patrol cars and a white patrol car, all with flashing lights:

    Candidate Motorcade - 5792
    Candidate Motorcade – 5792

    The officer jumped into his car and rejoined the procession at the end:

    Candidate Motorcade - 5992
    Candidate Motorcade – 5992

    According to my back-of-the-envelope, the motorcade moved through the intersection at a steady 20 mph.

    Given where all the folks who merit such an escort were supposed to be at the time, I don’t know why they brought The Personage through the Red Oaks Mill intersection in that direction; the City of Poughkeepsie is to our rear, due north of Red Oaks Mill. Perhaps they’re following a randomly chosen route to confuse the unprepared, even though it’s longer and requires more traffic control?

    Rumors from a Reliable Source indicate that not all trains travel on steel rails.

    I suppose you eventually get used to having a couple of quiet people standing in every room with you.

    One benefit of the inevitable news coverage: a few more people now know how to pronounce “Poughkeepsie”.

  • Discrete LED Aging

    We all know that LED brightness decreases with age. An exit sign in Vassar’s Skinner Hall shows what that looks like in real life:

    Exit Sign - LED aging
    Exit Sign – LED aging

    The LEDs on the other side of the sign look about the same: a few very bright spots, a few very dim ones, and a whole bunch in the middle.

    It’s hard to judge by eye, but the brightest LEDs look much more than a factor of two brighter than the dimmest ones.

    An LED with a 50,000 hour lifetime will have 50% of its initial brightness at EOL and a year has 8,766 hours, so the LEDs will reach half-brightness in a bit under six years. I think discrete LEDs went out of style around the turn of the millennium, so it’s three half-lives old: the dimmer LEDs must be around 1/8 brightness.

    In case of an actual emergency, just follow me out the door, OK?

  • Demolition Card GTA 5-10-9

    So I found two copies of the US Army’s Demolition Card GTA 5-10-9 tucked under a row of completely unrelated books in the Basement Laboratory (clicky for more dots):

    Demolition Card GTA 5-10-9 - 1
    Demolition Card GTA 5-10-9 – 1
    Demolition Card GTA 5-10-9 - 2
    Demolition Card GTA 5-10-9 – 2
    Demolition Card GTA 5-10-9 - 3
    Demolition Card GTA 5-10-9 – 3
    Demolition Card GTA 5-10-9 - 4
    Demolition Card GTA 5-10-9 – 4

    All four images wrapped up in a convenient PDF for your printing amusement:
    Demolition Card GTA 5-10-9

    One can only hope it’s slightly more useful than the Calculator Set, Nuclear, M28 — FSN 6665-897-8697 on another shelf. It dates back to the era when you could get ammonium nitrate that went blam when prompted; rumor has it that retail fertilizer now comes with built-in detonation inhibitors.

    Essentially all adult human males have a story including the phrase “but for an (inch | second), I wouldn’t be here” … it’s a survivor bias thing.

  • Monthly Image: April Snow

    An unusually late two-day snowstorm laid down half a foot of snow starting in the evening of April 3:

    Norway Spruce  with April snow
    Norway Spruce with April snow

    Up until then, the weather had been running a bit warmer than usual, which seems to be the new normal, and this snowfall put more snow on the ground than we’d seen all winter.

    The snow took some critters by surprise:

    Sparrow - nest box in April snow
    Sparrow – nest box in April snow

    Most of the snow melted during the sunny 40 °F day after the storm, but overnight lows in the teens wiped out most of the spring flowers and buds.

  • Overstuffed First Solid Infill Layer Debugging: FAIL

    The first pass at the lip balm holders suffered from a grossly overstuffed first solid infill layer:

    Overfilled layer 2
    Overfilled layer 2

    The skirt measured the usual scant 0.25 mm and was level all around, so the platform alignment and home position were just fine. That’s rarely a problem, but it’s good to verify before proceeding.

    Previewing the G-Code didn’t show any problems; all the second-layer threads looked just fine. With that said, I did create an issue for gcode.ws pointing out that the profusion of thread colors wasn’t useful and suggesting some alternative methods.

    The first layer requires 15-ish minutes to print, so I decided to reproduce the problem in a solid calibration box sliced with the same settings as the holder:

    Calibration boxes - solid
    Calibration boxes – solid

    That still life represents these tests:

    • Solid 3 mm tall box, 20 mm square
    • 30 mm square
    • 25 mm square, with text in Arial
    • Again, because I can’t believe it hasn’t failed yet
    • With rectilinear first layer
    • Back to Hilbert with text in Zapf Chancery

    All of those printed without trouble; every layer came out exactly as it should. In particular, the first solid infill layer atop the Hilbert Curve bottom layer had the precisely filled threads I’m used to seeing, each one butted against its neighbors without any excess plastic.

    I modified the OpenSCAD source code to extract a 20x20x3 sample block from the lip balm holder model, including a snippet of the actual text. That worked fine.

    Expanding the sample produced the irregular chunk in the front row, also 3 mm tall, including a section of the lilypads surrounding the tubes. Another successful print!

    I’ll leave to your imagination a pile of half a dozen first layers topped with small sections of grossly overstuffed solid infill, printed in between the successful blocks and as a result of the variations mentioned below, with identical text and slicer settings. The test blocks work fine, but the actual holder and sections from it do not.

    Having eliminated the obvious causes, it was time for more drastic measures.

    I build OpenSCAD and Slic3r from the latest source files on GitHub. Nothing in this leads me to suspect the OpenSCAD models and using the most recent stable Slic3r version produced the same results.

    Rebuilding the Slic3r configuration files from scratch produced the same results.

    That’s where I gave up, set the 3D Honeycomb infill to start with Layer 2, and completed the mission.

    Lacking any better ideas, I decided to throw all the balls in the air at once …

  • Kohl’s Guest WiFi Terms & Conditions: The Short Version

    I enjoy exposing my tired old Kindle to random assaults, so I’m always on the lookout for FREE WIFI! hotspots:

    Kohls Guest WiFi - login screen
    Kohls Guest WiFi – login screen

    You can’t resize the text, there are no linkies to the details of the Kohl’s Terms or Kohl’s Privacy Policy (viewing them would presumably require a browser, which would require using the WiFi, which you haven’t yet been approved to use), leaving a decision between “Hit me!” and, oh, maybe re-reading The Martian.

    In the local Sears some months ago, I spent the better part of 20 minutes scrolling their lengthy T&C, following the links (which they provide through the same peephole!), and generally admiring their legal department’s sophistry.

    I’m not a formal member of The Society for the Easily Amused, but I support their cause and, obviously, don’t get out nearly enough.

  • Vacuum Tube Prices, Then and Now

    Quite by coincidence, a Pile o’ Stuff disgorged a 1975 Radio Shack Catalog listing three dense pages of vacuum tubes, including a 21HB5A:

    Radio Shack 1975 Catalog - 21HB5A Tube Listing
    Radio Shack 1975 Catalog – 21HB5A Tube Listing

    These days, you buy New Old Stock 21HB5A tubes from eBay for about the same in current dollars with shipping:

    eBay - 21HB5A Tubes
    eBay – 21HB5A Tubes

    I should stock up and light up!

    Vacuum Tube LEDs - IBM 21HB5A Beam Power Tube - green violet phase
    Vacuum Tube LEDs – IBM 21HB5A Beam Power Tube – green violet phase