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?

  • Monthly Science: Supermoon Eclipse

    Lunar eclipses happens so rarely it’s worth going outdoors into the dark:

    Supermoon eclipse 2015-09-27 2250 - ISO 125 2 s
    Supermoon eclipse 2015-09-27 2250 – ISO 125 2 s

    That’s at the camera’s automatic ISO 125 setting. Forcing the camera to ISO 1000 boosts the grain and brings out the stars to show just how fast the universe rotates around the earth…

    One second:

    Supermoon eclipse 2015-09-27 2308 - ISO 1000 1 s
    Supermoon eclipse 2015-09-27 2308 – ISO 1000 1 s

    Two seconds:

    Supermoon eclipse 2015-09-27 2308 - ISO 1000 2 s
    Supermoon eclipse 2015-09-27 2308 – ISO 1000 2 s

    Four seconds:

    Supermoon eclipse 2015-09-27 2308 - ISO 1000 4 s
    Supermoon eclipse 2015-09-27 2308 – ISO 1000 4 s

    Taken with the Sony DSC-H5 and the 1.7 teleadapter atop an ordinary camera tripod, full manual mode, wide open aperture at f/3.5, infinity focus, zoomed to the optical limit, 2 second shutter delay. Worked surprisingly well, all things considered.

    Mad props to the folks who worked out orbital mechanics from first principles, based on observations with state-of-the-art hardware consisting of dials and pointers and small glass, in a time when religion claimed the answers and brooked no competition.

    NASA takes much better moon pix, plus a bonus ISS transit, during the previous full moon:

    ISS Moon Transit - 2015-08-02 - NASA 19599509214_68eb2ae39f_o
    ISS Moon Transit – 2015-08-02 – NASA 19599509214_68eb2ae39f_o

    The next eclipse tetrad starting in 2032 won’t be visible from North America and, alas, we surely won’t be around for the ones after that. Astronomy introduces you to deep time and deep space.

  • Anti-theft Device

    This thing may be theft-proof, even with the keys in the ignition:

    Trike vehicle with statue
    Trike vehicle with statue

    The trike is a Polaris Slingshot, but the statue looks full-frontal custom…

  • Alpha Geek Clock: New Battery

    After the CR123A lithium cell in the Alpha Geek Clock gave out:

    Packaged Alpha-Geek Clock
    Packaged Alpha-Geek Clock

    I duct-taped a pair of D cells onto the case and returned it to the bedroom shelf. According to the date scrawled on the tape, that was five years ago: 26 November 2010.

    Over the last few months, the LED gradually faded from a blink to a steady glow as the battery voltage dropped below 2 V and the WWVB receiver output no longer reached the MOSFET’s threshold.

    We’ll see how long these last:

    Alpha Geek Clock - new batteries
    Alpha Geek Clock – new batteries

    Yeah, I should probably do something involving 3D printing…

  • HP 7475A Plotter: Inmac Ball-Point Pen Tweakage

    The big bag o’ new-old-stock Inmac ball-point plotter pens had five different colors, so I popped a black ceramic tip pen in Slot 0 and ran off Yet Another Superformula Demo Plot:

    HP 7475A - Inmac ball pens - weak blue
    HP 7475A – Inmac ball pens – weak blue

    All the ball pens produce spidery lines, but the blue pen seemed intermittent. Another blue pen from the bag behaved the same way, so I pulled the tip outward and tucked a wrap of fine copper wire underneath. You can see the wire peeking out at about 5 o’clock, with the end at 3-ish:

    HP 7475A - Inmac ball pen - wire spacer
    HP 7475A – Inmac ball pen – wire spacer

    The wire holds the tip slightly further away from the locating flange and, presumably, makes it press slightly harder against the paper:

    HP 7475A - Inmac ball pen - stock vs. extended
    HP 7475A – Inmac ball pen – stock vs. extended

    A bit more pressure helped, but not enough to make it dependable, particularly during startup on the legend characters:

    HP 7475A - Inmac ball pens - extended blue
    HP 7475A – Inmac ball pens – extended blue

    That black line comes from an ordinary fiber-tip pen that looks like a crayon on a paper towel by comparison with the hair-fine ball point lines.

    Delicacy doesn’t count for much in these plots, so I’ll save the ball pens for special occasions. If, that is, I can think of any…

  • Zombie Pumpkins!

    You can’t make this stuff up:

    Surely, somebody already uses them for Halloween cosplay, but stuff like that is just crazy talk…

  • 3D Printer Platform Alignment: Details Matter

    Being that type of guy, I measure the single-layer skirt threads to keep track of the platform alignment. Most of the time, nothing happens, because the M2 has a remarkably stable platform, but some of the objects I’d done in early August showed more than the usual variation and, worryingly, no discernible trend.

    Successive sets of thinwall hollow boxes showed the instability:

    M2 Alignment measurements - 2015-08-09 - 1
    M2 Alignment measurements – 2015-08-09 – 1

    Adjusting the platform alignment between each of those sets produced no consistent effect, which is most unusual. The X in the bottom set shows where that thinwall box came unstuck from the platform, indicating that the clearance was considerably more than the nominal 0.25 mm layer height.

    Peering under platform revealed something else that was quite unusual:

    M3 washer - bad seating
    M3 washer – bad seating

    That washer should be flat against the spider mounting plate. My first thought was a burr on the plate, but that didn’t make any sense, as the plate was clean & smooth when I installed the platform; I’d enlarged those holes with a fine file and would have checked for burrs as part of that operation.

    Removing the screw nut and extracting the washer revealed the true problem:

    M3 washer with burrs
    M3 washer with burrs

    It’s a bad washer!

    Tossing that one in the trash and installing a good washer put everything in order:

    M3 washer - proper seating
    M3 washer – proper seating

    Well, that’s after re-doing the alignment to un-do the previous flailing around, of course.

    As nearly as I can tell, that washer sat there without causing any trouble since I installed the hotrod platform. or, more likely, when I repaired a failed screw. In late July I poked the platform to measure how much it moved under pressure, which apparently dislodged the washer and put the burr in play.

    That’s how sensitive a 3D printer is to mechanical problems…

  • Craftsman 1231.3817 Power Hammer: Fire in the Hole!

    For reasons that aren’t relevant here, I had to reinforce some old basement stairs. Rather than drilling holes, sinking anchors, and installing screws, I just nailed painted 2×4 strips to the foundation using this Craftsman 1231.3817 Power Hammer, which is not available in a Sears / Kmart near you:

    Sears Craftsman Power Hammer
    Sears Craftsman Power Hammer

    It’s a handheld gun that drives two inches of hardened steel nail into solid concrete by firing what looks like an overstuffed 0.22 Short blank cartridge: load a nail, fit a cartridge, press the muzzle firmly against the target, and whack the butt end with a hammer.

    Worked like a champ. Scary as you’d imagine.

    If the nail stands proud of the surface, you can hit it again with a low(er) power load to drive it the rest of the way. Sometimes that sinks it below the surface, leaving a cylindrical pit. In the situations where I use this thing, nobody will ever notice.

    It’s similar to the Remington Model 476 Powder Actuated Fastening Tool (manual), which you can get from Amazon and surely other vendors; fancier versions also exist. Equally surely, they’re illegal in some jurisdictions.

    I have reason to use it every few decades, which is entirely enough for me…

    Wear goggles, earplugs, gloves, and don’t get stupid.