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

  • Evapo-Rust vs. Battery Contact Corrosion

    A long-forgotten toy emerged from the heap bearing a trio of corroded NiMH cells between the usual plated-steel contacts:

    Corroded contacts - original
    Corroded contacts – original

    The toy wasn’t worth salvaging, but I extracted the contacts and applied Evapo-Rust to see what happened. After an overnight soak, some corrosion remained:

    Corroded contacts - after Evapo-Rust
    Corroded contacts – after Evapo-Rust

    Scrubbing with a stainless-steel detail brush removed the flakes and left reasonably clean metal behind:

    Corroded contacts - after brushing
    Corroded contacts – after brushing

    Although it’s not beautiful, I think the contacts came out as well as one could expect. The longer contact plate has holes, thinned sections, and some corrosion inside the spring; I’d be mildly tempted to rebuilt the whole thing with some nickel shim stock and a new spring.

    If I were salvaging the toy, I’d dab vinegar on the wiring to neutralize the creeping potassium hydroxide, rinse the whole thing with water, and clean out the case. Instead, it joined the consumer electronics recycling box with a thud…

  • Magazine Billing Network: Same Scam, Different Name

    This just in: an offer to subscribe to The Economist at a mere $50 over sticker price…

    Magazine Billing Network - Not A Bill
    Magazine Billing Network – Not A Bill

    Apart from the name, everything matches that Subscription Billing Service scam: same layout, same (non-toll-free) phone, same address.

    Perhaps the SBS name became too hot to handle?

    At least they’re not the never-sufficiently-to-be-damned telephone scammers…

  • Belt Gluing

    When I bought a new belt some months ago, I thought the lack of stitching meant it was made from a single strip of leather. Come to find out that it’s actually two strips glued together with something sticky that came un-done at the point where the belt passes through the buckle.

    So I peeled a bit more apart, smoothed a thin layer of urethane glue (aka Gorilla Glue) inside, laid waxed paper on both side just in case the foam expanded beyond my wildest imagination, and clamped it together:

    Belt clamping
    Belt clamping

    The glue layer turned out just about perfect, with only a few blobs sticking out the sides:

    Belt with urethane glue blobs
    Belt with urethane glue blobs

    Those blobs snapped off easily enough and the belt works fine again.  We’ll see how long this one lasts…

  • Forsythia Clearing

    It was decided, in that place where what is decided must be, that the time had come to hack back the giant forsythia stand encroaching from the neighbor’s yard. The stuff tip-roots, so anything that stands in its way gets assimilated, and the only way to make headway is to tear it out by the roots.

    We eventually clearcut a section about 15 feet wide and 40 feet long by the simple expedient of lopping off everything that stuck up:

    Cleared Forsythia
    Cleared Forsythia

    Removing the roots required prying with a 7 foot length of 1.5 inch octagonal steel bar braced on a chunk of 4×4 inch lumber rammed up against the roots. With my full weight on a 6 foot lever arm, the roots would just barely break free.

    A dozen wheelbarrow loads like this went atop the branches on the heap:

    Forsythia root balls
    Forsythia root balls

    That’s my kind of outdoor work: kill them all…

    Mary raked and seeded the debris field just before the next rainfall. It ought to be good for another few years.

  • Lenovo Headset Boom: Repair Faceplant

    I picked up a Lenovo headset on sale and over the course of a few weeks the mic boom pivot worked itself loose, until I finally dismantled the left ear cup to see what was inside. Come to find out that the mic boom has a molded threaded section held into the cup with a simple nut and no locking mechanism at all:

    Lenovo headset - OEM mic boom pivot nut
    Lenovo headset – OEM mic boom pivot nut

    I think the metal washer was intended as a low-friction pivot atop the compliant silicone (?) washer underneath, but the net effect was that the nut unscrewed a little bit more every time the mic boom moved. By the time I got in there, the nut was completely off the threads.

    The original nut left a thread or two showing, so I found a thicker replacement nut with a better grip. The obvious solution involves a dab of Loctite to jam the nut in position, but we all know that some plastics, most notably acrylic, react badly to threadlocker and tend to disintegrate. Although I considered just epoxying the nut in place, that seems so, well, permanent.

    So I dutifully tested a dab of Loctite on an inconspicuous spot inside the ear cup, got no reaction at all, put a drop on the boom pivot threads, and reassembled everything:

    Lenovo headset - replacement mic boom pivot nut
    Lenovo headset – replacement mic boom pivot nut

    Alas, by the time I got back upstairs and hung the mic on the rack, the boom fell completely out of the earcup! Back in the Basement Laboratory, I dismantled the thing again and confronted this mess:

    Lenovo headset- Acrylic plastic vs. threadlock
    Lenovo headset- Acrylic plastic vs. threadlock

    Huh. The ear cup isn’t made of the same plastic as the mic boom: one shrugs off threadlock, the other disintegrates.

    That’s obvious in retrospect, eh?

    The only threads that aren’t ruined lie completely within the ear cup frame, with just a stub sticking up around the wire. So I cleaned things up and did what I should have done originally: put a dab of epoxy inside the nut to bind the pivot firmly in place. A snippet of unshrunk heatshrink tubing around the wire provides a bit of strain relief:

    Lenovo headset - boom pivot nut with epoxy
    Lenovo headset – boom pivot nut with epoxy

    There’s no longer any space for the compliant washer in that stack, so we’ll see how long this lasts. The next repair will certainly venture far inside non-economical territory. I like the headphones, though.

    Memo to Self: Check in an inconspicuous spot on the same material.

  • Toyota Sienna: Hatch Latch Handle Replacement

    Sienna hatch - replacement latch
    Sienna hatch – replacement latch

    The replacement metal latch handle fit perfectly and works fine.

    That skinny protruding arm shouldn’t break off, but now it has a metal-to-metal sliding joint that will eventually gall. With any luck, though, it’ll outlast the van… which, admittedly, that kludged repair probably would have, too.

  • Credit Card Services: A Tinge Of Doubt Crosses His Mind

    This call from Credit Card Services lasted about a minute, but was highly informative. I pressed 1 to lower my interest rates, then …

    CCS: This call is regarding an issue with your Visa and Mastercard credit card accounts. Based on changes in your credit score and repayment history over the last twelve months, you may be eligible for a lower interest rate. In order to qualify, you must have a balance on at least one card of at least $4000. Is that the case?

    Me: Sure.

    CCS: The interest rate on that account must average more than 12 percent. Is that the case?

    Me: Sure.

    CCS: I must verify your phone number. Our records show that it is [reads off number].

    Me: Sure.

    CCS: And your name is [reads off my formal name, which shows he doesn’t know me from Adam Smith].

    Me: Sure.

    CCS: What is the total balance on all your credit cards?

    Me: Well, that’s hard to say.

    CCS: All we need is an estimate.

    Me: Let’s call it ten grand. [This is a lie. Next time, I’ll say twenty grand.]

    CCS: And how many credit cards do you have?

    Me: Four. [Also a lie. Next time, I’ll say eight.]

    CCS: [background chatter, loud crash, call disconnects.]

    Previous Credit Card Services contestants have sworn that they do not know what number they dialed. After you pass a minimum qualification, well, suddenly they do know your number and your name. Huh. Who’d’a thunk it?

    This contestant did not pass me to the CCS Level 2 Closer, the guy who attempts to tongue-wrestle victims into divulging a credit card number that he will instantly siphon money out of. We recently burned the balance in a gift card obtained for test-driving a Toyota (hey, I won’t pass up free money), so maybe I’ll feed those digits into the next call.

    If I sounded more enthusiastic, I’m sure I could reach the Closer!

    I used to think that a sensible person running a scam like CCS would make it a point to not re-call smartasses who jerk my reps around. Now, I’m sure the reps run on pure commission and the marginal cost of making a phone call sits right around zero, so the sensible person running CCS has nothing to lose.

    Search herein for Credit Card Services (or just CCS) to find previous installments of this continuing adventure.

    The title is a tip o’ the cycling helmet to Zappa:

    Motorcycle Man: Well, let’s make a deal if you think that’s true
    I mean, you’re the devil, so whatcha gonna do?

    Devil: Wait a minute. A tinge of doubt crosses my mind
    When you say that you want to make a deal with me.

    You find the rest on your own, OK?