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

  • Measuring Spoon Drainer

    We just scrapped out the old dish drainer, only to find the gadget bin on the new drainer let the measuring spoons fall over and lie along its bottom. After a week of fishing them out from under paring knives, cheese slicers, and suchlike, I gimmicked up a holder:

    Measuring Spoon Drainer - installed
    Measuring Spoon Drainer – installed

    One might suggest natural PETG, rather than orange, thereby displaying a shocking ignorance of the MVP concept. We’ll run with orange for the shakedown trials, then build-measure-learn, iterate, and, for all I know, we may even pivot.

    A bottom-up view of the solid model shows the trench accommodating the bin lip:

    Measuring Spoon Drainer - Slic3r preview
    Measuring Spoon Drainer – Slic3r preview

    The OpenSCAD source code as a GitHub Gist:

    // Measuring spoon drainer
    // Ed Nisley KE4ZNU – 2018-01-13
    /* [Extrusion] */
    ThreadThick = 0.25; // [0.20, 0.25]
    ThreadWidth = 0.40; // [0.40]
    /* [Hidden] */
    Protrusion = 0.1; // [0.01, 0.1]
    HoleWindage = 0.2;
    function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);
    ID = 0;
    OD = 1;
    LENGTH = 2;
    //- Adjust hole diameter to make the size come out right
    module PolyCyl(Dia,Height,ForceSides=0) { // based on nophead's polyholes
    Sides = (ForceSides != 0) ? ForceSides : (ceil(Dia) + 2);
    FixDia = Dia / cos(180/Sides);
    cylinder(r=(FixDia + HoleWindage)/2,h=Height,$fn=Sides);
    }
    /* [Spoon] */
    SpoonOD = IntegerMultiple(3.3,2);
    SpoonWidth = IntegerMultiple(16.5,2.0);
    SpoonOC = 30.0;
    /* [Drainer] */
    Drainer = [52.0,59.5,100.0]; // overall drainer cup
    DrainerRimWidth = (Drainer[1] – Drainer[0])/2;
    DrainerRimHeight = 2.5;
    DrainerExtent = 15.0;
    /* [Hidden] */
    WallThick = 2.0; // basic wall & floor thickness
    PlateThick = WallThick + 2*DrainerRimHeight;
    NumSides = 8*4;
    //—–
    // Define shapes
    module CoverPlate() {
    OD = Drainer[OD] + 2*WallThick;
    difference() {
    cylinder(d=OD,h=PlateThick,$fn=NumSides);
    for (j=[-1,1])
    translate([-(OD/2 – Protrusion),j*(Drainer[ID]/2 + DrainerRimWidth/2),WallThick + DrainerRimHeight + Protrusion/2])
    cube([OD,DrainerRimWidth,2*DrainerRimHeight + Protrusion],center=true);
    translate([0,0,WallThick + PlateThick/2])
    rotate(-90)
    rotate_extrude(angle=180,$fn=NumSides)
    translate([Drainer[ID]/2 + DrainerRimWidth/2,0])
    square([DrainerRimWidth,PlateThick],center=true);
    translate([-(OD/2 + DrainerExtent),0,PlateThick/2])
    cube([OD,OD,PlateThick + 2*Protrusion],center=true);
    }
    }
    //—–
    // Build it
    difference() {
    CoverPlate();
    for (j=[-1,1])
    translate([0,j*(SpoonOC/2),-Protrusion])
    linear_extrude(height=PlateThick + 2*Protrusion)
    hull()
    for (i=[-1,1])
    translate([i*(SpoonWidth – SpoonOD)/2,0])
    circle(d=SpoonOD,$fn=8);
    }

    The original doodle has useful dimensions, along with the usual over-elaborate features sacrificed in order to get it made:

    Measuring spoon drainer - doodles
    Measuring spoon drainer – doodles
  • Egg Size Distribution

    We got several cartons of “medium” brown eggs with what seemed like an unusually wide size distribution, so I picked out and weighed an assortment for future reference:

    Brown egg size distribution
    Brown egg size distribution

    Of course, there’s an egg size specification. Actually, there are many egg size specifications.

    We occasionally get huge eggs, tiny eggs, eggs with two yolks, no yolks, or blood-spotted yolks, all of which turn out to be no big deal. I admit to not previously encountering the term “fart egg”, however …

  • Low Budget Bench Power Supply

    The idea behind this gadget surfaced while I was looking for something else and, although the front panel makes my skin crawl, it’s just an adjustable DC power supply:

    Tattoo power supply - original front panel
    Tattoo power supply – original front panel

    This is apparently the cheapnified version of the item appearing in the eBay listing:

    Tattoo Power Supply - eBay listing photo
    Tattoo Power Supply – eBay listing photo

    Let’s say it has the potential to be a DC power supply, although we might quibble about the “Precision” part.

    As delivered, it’s a deathtrap. Of course, it’s not UL listed and I didn’t expect it to be.

    How many lethal problems do you see?

    Tattoo power supply - original AC wiring
    Tattoo power supply – original AC wiring

    For starters, it has a three-wire AC line cord with the green-and-yellow conductor chopped off flush with the outer insulation inside the heatshrink tubing just behind the transformer:

    Tattoo power supply - ungrounded AC line
    Tattoo power supply – ungrounded AC line

    The blue wire is AC neutral, but it really shouldn’t be connected to the finger-reachable outer fuse terminal.

    The brown wire is AC line, which goes directly to one power switch terminal. In the event of a hot wiring fault, an unfused conductor touching the case will test the GFI you should have on your bench wiring.

    The AC line cord uses some mysterious copper-colored metallic substance that’s about as stiff as music wire:

    Tattoo power supply - stiff AC wire
    Tattoo power supply – stiff AC wire

    The strands cannot be twisted together like ordinary copper wire, although they can be soldered. They may be copper-plated aluminum, because a magnet ignores them.

    After soldering the strands together, they snap when bent:

    Tattoo power supply - soldered broken AC wire
    Tattoo power supply – soldered broken AC wire

    Generous strain relief is not just a good idea, it’s mandatory.

    After some Quality Shop Time, the ground wire now connects to the case through the transformer’s rear mounting screw, the neutral AC wire connects to the transformer, the hot AC wire goes to the tip of the line fuse, and the fuse cap terminal goes to the switch:

    Tattoo power supply - AC line rewiring
    Tattoo power supply – AC line rewiring

    I relocated the white LED to the middle of the meter, where it looks a bit less weird:

    Tattoo power supply - revised front panel
    Tattoo power supply – revised front panel

    I have no idea what “Porket indicate” might mean. Perhaps “Precision indicator”?

    The right 1/4 inch jack, labeled “Foot”, normally goes to a foot switch you don’t need for a bench power supply, so I converted a length of drill rod into a dummy plug to short the jack contacts:

    Tattoo power supply - dummy switch plug
    Tattoo power supply – dummy switch plug

    The tip comes from a bit of lathe and file work and the white cap comes from a bag of wire shelf hardware.

    A genuine hologram sticker (!) on the back panel proclaims “1.5 – 15 VDC 2 A”, which seemed optimistic. Some fiddling with power resistors suggests tattoo liners (I learned a new word!) don’t draw much current:

    • 4 V @ 1 A
    • 8 V @ 800 mA
    • 10 V @ 600 mA

    It can reach a bit over 18 V (pegging the meter) at lower current, so it’s Good Enough for small projects with un-fussy power requirements.

    Caveat emptor, indeed.

  • Stainless Steel Water Bottle: FAIL

    Although I repaired the spout a while ago, those water bottles were never satisfactory and saw very little use. A recent cabinet cleanout showed the “stainless steel” has passed beyond its best-used-by date:

    Stainless steel water bottle - rust
    Stainless steel water bottle – rust

    With no regard for whether the patient would survive the operation, I peeled off its rubber foot and applied the Lesser Hammer:

    Stainless steel water bottle - insulation
    Stainless steel water bottle – insulation

    The “insulation” seems to be a rigid urethane-like foam disk few millimeters thick on the bottom of the interior flask, with good old air around the sides.

    The bottles never worked very well and now we know why.

    Gone!

  • Eyeglass Temple Re-re-repair

    After three years, the temple screw on Mary’s oldest and most-battered “reading” glasses worked loose. A dab of low-strength Loctite should hold it in place forever more:

    Reading glasses temple repair
    Reading glasses temple repair

    That brass stake pin certainly adds a Steampunk flair to the proceedings …

  • Lathe-Turned Almond Butter

    Pure almond butter comes with the somewhat stilted admonition “Must stir product. Oil separation occurs naturally.” I’d just opened a new jar and was busily (and laboriously) stirring when I realized we have the technology:

    Lathe-turned Almond Butter
    Lathe-turned Almond Butter

    I installed the chuck’s outside jaws to grab the jar lid.

    About three hours at 50 rpm, the lathe’s slowest speed, did the trick. We now have the smoothest, creamiest, best-mixed almond butter ever.

    In a month or so, I’ll chuck up an unopened jar to see how well it works without any manual intervention.

     

  • Doing Biz On eBay

    I’ve always wondered what the Chinese-script company names on eBay meant, so I fed some into Google Translate (clicky for more dots):

    Chinese eBay Company Names
    Chinese eBay Company Names

    Huh.

    As the saying goes, ol’ Deng must be living “… modestly, if the kind of money he was getting out of me meant anything to him.”