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.

Month: October 2012

  • Screwdriver Rack

    A while back I picked up one of Harbor Freight’s cheap screwdrivers sets; the largest two drivers far exceed my simple needs, but the smaller screwdrivers work surprisingly well. I couldn’t figure out where to store the things, as they’re used often enough to remain ready to hand, while being too bulky for any of the drawers. Emboldened by my success with those shoe latch springs, I decided to bend some coat hanger wire into simple clips that grab the screwdrivers around their waists:

    Screwdriver clip - rear view
    Screwdriver clip – rear view

    The first step forms a loop where the mounting screw will go; squeezing the wire around the pin with pliers made a reasonably good imitation of a screw hole:

    Screwdriver clip - screw bend
    Screwdriver clip – screw bend

    The next two bends shape the wire to the arms; I eventually figured out that bending the wire ends to a mutual right angle worked out better than the acute angle you see here:

    Screwdriver clip - second bend
    Screwdriver clip – second bend

    Bending both wires at a right angle formed the arms:

     Screwdriver clip - arm bend
    Screwdriver clip – arm bend

    Two more bends in each arm finished off the clip:

    Screwdriver clip - entry bends
    Screwdriver clip – entry bends

    I chopped up a coat hanger with smaller diameter wire to make clips for the smallest screwdrivers with narrower handles.

    Repeat that a dozen times, drill pilot holes into a ready-to-use bit of scrap lumber, screw the clips with 3/4 inch flat-head screws, add four more holes on the right for finishing nails to hold the red screwdrivers (which have suitable holes in their handles), screw the whole affair to the bottom of the floor joist, and it’s all good:

    Screwdriver rack on floor joist
    Screwdriver rack on floor joist

    After running the first half dozen screws with great effort, I fetched the beeswax and the rest slid right into place.

    The larger driver handles stick up inconveniently far behind the fluorescent lamp fixture that’s barely visible along the top, but (I’m pretty sure) I won’t use those nearly enough for that to be a problem.

    I suppose I should dip the raw ends of the wires in goop to avoid harpooning myself; I think I’ll mostly handle the screwdrivers by their shafts, so maybe that won’t be a problem, either.

    Memo to Self: Use the beeswax!

  • Splinting an Umbrella Strut

    One of the ribs in the six-passenger umbrella we keep in the van snagged on something and snapped its fitting on the spreader strut:

    Umbrella strut - broken connector
    Umbrella strut – broken connector

    This being wonderful engineering plastic that cannot be solvent-bonded, epoxy is the only adhesive that will work. However, those joints undergo tremendous stress in a deployed umbrella, so a bare epoxy joint won’t have enough strength for the job. What to do?

    Wonder of wonders, when I got the umbrella into the Basement Laboratory Repair Wing, I discovered:

    • The not-quite-round strut fitting stub slipped right into a short brass tube from the heap and
    • Just enough of the fitting remained on the rib to anchor the tubing

    A silicone tape wrap kept most of the epoxy inside while it cured:

    Umbrella strut - epoxy curing
    Umbrella strut – epoxy curing

    Clearing off a few blobs made it all good:

    Umbrella strut - brass tubing splint
    Umbrella strut – brass tubing splint

    We don’t play golf, but such a big umbrella keeps most of the rain off two people; it’s a tchotchke from back when Mary worked at IBM (hence the color scheme). We call it our “six-passenger” umbrella because it looks about that big when we deploy it…

  • Monthly Picture: Laboratory Study of the Grasshopper

    My father drew this in his Sophomore Biology Laboratory Notebook:

    Laboratory Study of the Grasshopper
    Laboratory Study of the Grasshopper

    Can you imagine the attention span required to draw that with no obvious errors? The next four pages contain a hand-written discussion of the grasshopper, with two corrections; he filled the entire notebook using a pen and four colors of fluid ink.

    Here’s a closer look at the grasshopper (clicky for more dots):

    The Grasshopper
    The Grasshopper

    I cannot imagine assigning that task to present-day students…

    Things were different in 1927, when he was 17 years old. They were about to get really different; 15 years later he was in the South Pacific.

  • Grace Under Pressure

    We toured the USS Albacore (AGSS 569) in Portland NH and found this placard in the forward Escape Trunk (which doubled as the normal hatch during the sub’s nautical lifetime):

    Escape Trunk Operating Procedure
    Escape Trunk Operating Procedure

    One of my relatives is a submariner who seems calm & collected enough to remember that entire checklist in an emergency.

    The heads bore similar placards, along the lines of the classic scene in 2001: A Space Odyssey.

    The camera lens they used for their virtual tour pictures would lead you to believe there was actually enough space inside the sub to inhale. That was not the case and I was very glad to have only half a dozen other people touring the sub with us.

    Our hotel room (on the top floor of Wentworth by the Sea, egad) had a good view of the Portsmouth Naval Shipard (also see Wikipedia) across the Piscataqua River, where the USS Miami  (SSN 775) remains discreetly under cover.

  • The Value of Childhood Rhymes

    Saw this in Lowell MA outside the Bootts Cotton Mill Apartments:

    DO NOT ENTER - unusual date
    DO NOT ENTER – unusual date

    The way I learned it:

    Thirty days hath September,
    April, June, and November.
    All the rest have thirty-one,
    Except February, which is all messed up.

    Maybe the River Walk reopens on the Twelfth of Never?

  • Bicycle Mobile: New Windscreen Mic Ball

    The bikes stand upright inside the van and the helmets ride on the floor with all their stalks sticking up. This usually works out well, but on our last trip my helmet rolled under my bike and rubbed the foam ball surrounding its mic against the chain, producing a result so awful that I had to install new foam.

    For posterity, here’s the current state of the electret mic and its mount:

    Electret mic on bike helmet boom
    Electret mic on bike helmet boom

    The foam comes from a sheet of Sonex acoustic foam baffle, snipped into a reasonable approximation of a ball, with a slit deep enough to surround the mic, and a cable tie holding it closed:

    Foam mic ball on bike helmet boom
    Foam mic ball on bike helmet boom

    For what it’s worth, I’ve found that excessive wind noise correlates with too much mic gain. The mic rides about a finger’s width from the corner of my mouth, I talk at a normal volume, the amp supplies about 20 dB of gain, and we have no trouble with wind noise. The amp gain depends on the mic sensitivity, so your results will certainly differ; these mics came from the heap with no specs whatsoever.

    I suppose wind noise also depends on the bike’s speed, but when I’m going that fast I don’t have enough brain or lungs left over to hold a conversation…

  • Sink Soap Dispenser Pump: Nozzle Fitting

    The absurdly heavy pump nozzle atop the kitchen sink soap dispenser seemed more wobbly than usual. Some investigation suggested the fitting atop the plastic pump has gotten smaller, which may be due to having the nozzle wobble around on it.

    In any event, a wrap of Kapton tape snugged it up just fine:

    Sink soap dispenser pump
    Sink soap dispenser pump

    We’ll see how long that lasts; this thing may be nearing the end of its useful life.