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: Home Ec

Things around the home & hearth

  • The CD That Wouldn’t Play

    Misshapen CD Hole
    Misshapen CD Hole

    Mary popped a CD into the boom box, poked the Go button, and the display read “No Disc”… which was odd, as the larger player in the living room had gotten halfway through it with no trouble.

    A bit of diagnostic winnowing revealed a ding on one side of the CD’s hole, as though it had been mashed by a heavy object. These CDs (it’s 13 of 16 in an audio book) aren’t new, but they’ve been reasonably well treated by all parties. It looks like it might have been crunched in a player, which you’d think would be impossible.

    The disc seemed to seat firmly on the player’s hub, so I suspect the ding put the CD far enough off-center to defeat the player’s track acquisition and following algorithm.

    A long time ago I wrote exactly that firmware for a prototype video disk player: find a one-micron track with a one-micron beam while the track wobbulates a few hundred microns as the disk spins at 3600 rpm. After that, mapping the track eccentricity and following it around the disk was a simple matter of software…

    In this case, a bit of razor-knife surgery removed the plastic intruding into the hole and set everything to rights.

  • Money for Nothing: Nielsen TV Survey

    Just got a check for twenty bucks in the mail:

    Nielsen Survey Thanks
    Nielsen Survey Thanks

    That’s in addition to the ten dollars folding cash money enclosed with the survey as, I suppose, a motivation to not chuck the whole thing in the trash.

    The survey told us that our household had been “scientifically selected” to ensure a valid sampling of the TV viewing population, so it was very important to return the survey. I was astonished that they’d pay thirty bucks for a survey, but that’s probably a good indication of their desperation.

    OK, sez I, I’ll play along; every man has his price.

    It took ’em until Question 4 to get to the heart of the matter: how many television sets does our family own? Surprisingly, the first choice was “None” and, because that best describes our situation, that’s what I picked. Most of the other questions didn’t have a “Hell, no!” response, but I picked the smallest numbers, hours, and viewers they allowed.

    While there is, in fact, a TV in our house, it’s parked on a basement shelf with its cord wrapped around it and hasn’t been turned on in years. Sort of like the “iron phone” I keep in a box nearby; it comes out when I must verify that the phone company’s problem is upstream of the jack on the side of the house.

    And, besides, it’s an analog TV and we all know what that means: ain’t none of those signals on the air these days. Yes, we have a cable connection, but the only thing crossing the jack is Internet data and, IIRC, the Cablevision diagnostic channel.

    We have a lot of time for interesting & productive projects. They didn’t ask about that sort of thing, though.

    Our results were, most likely, something of a disappointment.

    [Update: OK, three times is enemy action. I will delete further comments asking to be signed up for the survey. ‘Nuff said.]

  • Corelle Sliver

    Mary found a sliver chipped from the outside edge of a Corelle dinner plate, which provides an opportunity to see something that’s normally invisible: the ceramic layer inside its glass coating.

    Overall, the sliver is nearly two inches long and about the same width as the plate is thick.

    Corelle sliver
    Corelle sliver

    Peering through the microscope at the left end, the glass layer is most obvious along the top edge. You can barely see it along the bottom, where the chip thins to a razor edge.

    Corelle sliver - detail
    Corelle sliver – detail

    On the right end the upper and lower glass layers are a bit more obvious, at least with the light arriving nearly horizontally and after some aggressive exposure hackage,

    Corelle sliver - side light
    Corelle sliver – side light

    The ceramic has a slightly higher coefficient of thermal expansion than the glass, so it puts the glass under a tremendous amount of compressive stress as the newly manufactured plate cools. Glass is really strong in compression (and terribly weak in tension), so the plate becomes remarkably hard to break. More details there and there.

    The plate rims do tend to chip, however, if you own them as long as we have. These are the long-discontinued Old Town Blue pattern: over three decades old by now.

    Oddly, they’re still under warranty: back in the day, Corning sold its then-new Corelle with a Lifetime Warranty. Nowadays, you get three years for the mid-grade line, five years for thicker plates, and a mere one year for stoneware (whatever that is). I suppose enough people actually took them up on the warranty to make it economically impractical.

    I ran a fine diamond file over the chipped edge and it’s OK. Eventually, we’ll break down and get new plates, but there’s no sense rushing a decision like that…

  • Rudy Sunglasses: Back From the Dead

    Clear lens installed
    Clear lens installed

    As expected, the uni-lens on Mary’s Rudy Project sunglasses cracked right up the middle as that stress crack above the nosepiece opened up. The sunglasses came with interchangeable lenses, so I swapped in the clear lens.

    Having used urethane adhesive to mechanically lock the defunct gray lens in place, the broken bits were pretty firmly bonded. I applied a brass hammer and small drift punch to the remaining tabs, pried the debris out of the temples, cleaned the adhesive from the recesses, and snapped the new lens in place. Surprisingly, it popped in and locked securely.

    The nosepiece has never worked satisfactorily: there’s nothing locking the flexible blue-silicone pad to the straight-sided posts that are supposed to hold it. As a result, it tends to pop off at the most inopportune moments.

    Rudy nosepiece
    Rudy nosepiece

    I dotted the posts on one side with cyanoacrylate and the other pair with epoxy to see if either will bond well enough to make a difference. If those fail, I’ll try urethane, although I’m not sure what will happen as the urethane expands in the sockets.

    Anyhow, she now has glasses suitable for biking on cloudy and rainy days… which is much better than a sharp stick (or a bug) in the eye, as we see it.

  • Chili Powder Beetles

    Mary cleaned out the kitchen cabinets, which entailed sorting out all the various spice jars. She thought the Chili Powder looked a bit odd and, indeed, it did: a whole colony of beetles and their larvae was a-squirm in there!

    The label states:

    All Natural

    non irradiated — no preservatives

    Frankly, I don’t see any particular problem with food irradiation.

    If you’re the sort of person who cooks your meals, as we are, then you’re eating plenty of denatured proteins and broken DNA anyway. In this case, snuggling that jar up to a nice warm Cobalt-60 slug for a few minutes would have been a great improvement.

    The main ingredient, of course, is “chili peppers”. The remainder doesn’t sound particularly life-sustaining, though: oregano, cumin, garlic, sea salt, and spices. Anything that can live off that brew must have a bad attitude, the way I see it.

    Being that sort of bear, I’d written the date on the label: 19 Aug 08. So, in round numbers, we use two ounces of Chili Powder a year. Obviously, we shouldn’t buy that stuff in bulk…

    Those are millimeters on the scale it’s crawling on, so these are little bitty bugs.

    [Update: Useful advice from the UC IPM folks.]

  • Waterless Urinal

    Waterless urinal
    Waterless urinal

    Our travels took us past a mall, in which I discovered another generation of waterless urinals. The general notion is that the cartridge contains a light oil that allows urine through to the drain, while blocking sewer gases just like an ordinary pipe trap.

    These Falcon urinals smell not at all like the Eau de Outhouse I found in Boston’s Hynes Convention Center some years ago; I suppose there was some pushback from the end-user community…

    IIRC, the Hynes restroom retrofit installed waterless drain cartridges in a standard urinal. Unfortunately, with no flush water to rinse the bowl, the urine simply dried in place with exactly the olfactory effect you’d expect.

    This urinal is obviously a custom-designed hunk of ceramic technology and, according to their copious literature, whizz just slides right off and runs through the Sloan cartridges on its way to the drain. I’m not sure how all that works, but things have certainly improved… or, perhaps, the mall does maintenance much more frequently than Hynes.

    Waterless urinal target
    Waterless urinal target

    Anyhow, that small dot a few inches above the cartridge seems like an aiming target. Speaking strictly as an amateur apiarist, the notion of “pee on the bee” isn’t all that attractive, but I suppose they needed some way to direct the stream away from the inlets …

    Urinal target
    Urinal target detail

  • Failed Switch

    Switch Innards
    Switch Innards

    When I flipped this switch on, it started fizzing and emitting ozone-scented smoke while the lights it controlled flickered. This is not a nominal outcome. I toggled the switch a few times, but it continued to misbehave, so I installed a replacement switch and laid the old one out on the desk for an autopsy.

    It’s an old-school mechanism, as suits the 1930-vintage structure it came from. The lyre-shaped arch with the spring swings back and forth on its tabs, which rest in the small recesses near the middle of the switch body. The peg on the toggle handle engages the spring, thus providing the over-center snap action.

    The switch action takes place at the bottom of the arch, where those two very small tabs stick out. They wipe on the grubby-looking bottom tabs of the oddly shaped flat-brass doodads, the U-shaped ends of which surround the screws that clamp the copper wire to the switch.

    I expected to find a scorched contact or perhaps an insect in the mechanism, but nothing seemed out of the ordinary. Apart, that is, from the layer of congealed grease covering everything inside. I suspect the grease was applied in the factory to help prevent contact corrosion, but the volatiles are long gone.

    Switch Contacts
    Switch Contacts

    A closeup of the switch contacts shows (what I think is) the problem.

    All the contact points are covered in grease, but the lyre-shaped gizmo looks like it’s been painted: its contact points were black and resisted cleaning by fingernail scraping.

    As nearly as I can tell, all the current passed through a very few high spots that were wiped somewhat clean as the contacts closed. As those spots heated up, the grease melted and flowed over them, increasing the resistance and the heat.

    The switch had been working for many decades, as the BX armored cable in the box had fabric-covered rubber (stiff rubber) insulation. I managed to install the replacement switch without breaking the insulation, but it was ugly in there.