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

  • 30 Year Clock: The Janus Movement

    After 30 years, IBM gave Mary a commemorative clock, after which she promptly retired. Back in the day, they used to hand out Atmos clocks (admittedly, on more momentous occasions), but this isn’t one of those. In fact, although it appears to have a torsion pendulum, that’s a separate motor-driven foo-foo which we immediately turned off:

    Janus Clock - front
    Janus Clock – front

    It normally sits on the living room coffee table (which actually holds a myriad plants next to the front window) where, after we scrapped all the upholstered furniture, the two of us can’t both see the clock face from our chairs. Having a spare clock insert from that repair, we had the same bright idea at the same time: we need a clock with two faces! We came up with Janus independently…

    Despite its fancy appearance, the IBM clock consists mostly of brass and plastic, so I had no qualms about having my way with it in the shop. The new clock insert spanned the clock’s gilt plastic back cover, needing only a #1 drill hole for the adjustment stem, and exactly filled the available space between the back cover and the case. Both movements had enough interior clearance for 3-48 brass screw heads and nuts, so I eyeballed the right spots on the new cover, centered the Sherline spindle on the plate, and drilled two clearance holes 6 mm in from the edges on the vertical diameter:

    Drilling clock insert cover
    Drilling clock insert cover

    That put them 61.3 mm apart across the diameter, which would be awkward to duplicate by hand. Manual CNC makes it trivially easy to match-drill holes; I clamped down the gilt back cover from the IBM clock, aligned it to the table, located the center, and drilled two 3-48 clearance holes:

    Drilling torsion clock cover
    Drilling torsion clock cover

    The glow from that polycarbonate packing block isn’t quite so nuclear in real life. The clamping force goes down the side panels of the cover, which had enough of a curve to be perfectly stable. Yes, I’m drilling into air, but came down real slow using the Joggy Thing and it was all good.

    Assemble the two back covers (the holes matched perfectly), mark the adjustment stem hole, disassemble, hand-drill, reassemble, tighten nuts, and install:

    Janus Clock - rear
    Janus Clock – rear

    It does look a bit lumpy from the side, but that’s just because I don’t have any gilding for the black tape wrap:

    Janus Clock - side
    Janus Clock – side

    There, now, that was easy.

  • Technical Excellence Clock: New Movement

    IBM Tech Excellence Award Desk Clock
    IBM Tech Excellence Award Desk Clock

    Long ago, in a universe far away, IBM gave Mary a desk clock as part of that Technical Excellence Award:

    The double-stick foam tape holding the plate on the front aged out a few years later, at which point I cleaned off the solidified goo, drilled 2-56 clearance holes in the plate and tapping holes in the clock base, installed four pan head stainless screws, and neatly aligned the slots. That’s what it should have looked like from the beginning; this was, after all, a Technical award…

    The clock movement failed recently and I got a drop-in clock insert from Klockit to put it back in operation. The fit wasn’t quite solid, but two wraps of silicone tape around the case under the ribbed friction-fit band solved that problem.

    One new movement cost just about as much as the shipping, so I bought a pair with black and white faces.  Mary picked the white face for this clock, which left the black movement as a spare.

    Tomorrow: what to do with a spare clock insert.

  • MTD Chipper-Shredder Screen: Replacement Thereof

    It’s leaf-shredding season again and our MTD Chipper-Shredder began shredding not nearly as well as it had in years gone by. Last season I laid in a stock of replacement parts, so I swapped in a new Shredder Screen (781-0457):

    MTD Chipper-Shredder screen
    MTD Chipper-Shredder screen

    The flail blades (719-0329) on the massive rotating impeller assembly protrude through the parallel openings in the screen, which is where most of the shredding action happens. The old red screen bent outward enough so that the blades pushed the leaves against the screen, rather than through it, producing frequent clogs.

    Now it works fine again… although I’ve had just about as much fun shredding leaves as any one person should experience in one month.

  • Garden Valve Corrosion

    The Vassar Farm Garden requires fairly heavy watering, because it’s in full sun all day long, so we lay in a set of drip lines connected through Y valves to a main feeder line running down one end of the plot. Plastic valves tend to be overly fragile, so this year I tried a few much larger full-flow ball valves with a metallic housing:

    Corroded Garden Y Valve
    Corroded Garden Y Valve

    This valve lay on the ground (as they all do) just inside the gate and served as an occasional supply for a short hose with the hand sprinkler head. I don’t know what’s driving this corrosion, but it’s eating the external threads as well as the valve bore.

    Overall, I’m unimpressed…

  • Automated Cookie Cutters: Plastic!

    The jellyfish cookie cutter and press look about the way you’d expect:

    Jellyfish Cookie Cutter and Press - separate
    Jellyfish Cookie Cutter and Press – separate

    They’re a bit more impressive on the build platform, where the skirt thread around the perimeter extends slightly beyond the usual 100 mm width limit into the no-go zone behind the nozzle wiper. The bizarre lighting from the warm-white front LEDs and the cool-white overhead LED ring emphasizes the 3D features:

    Jellyfish Cookie Cutter - on build platform
    Jellyfish Cookie Cutter – on build platform

    Somewhat to my surprise, the gritty nature of the bitmap source image didn’t cause a problem. The perimeters consist of many tiny segments, but most of the time goes to filling the interior (20% density, square pattern) and covering the flat surfaces, so the whole thing chugs along at a pretty good pace. Overall, it took something over an hour.

    So, given a height-map grayscale image:

    Manually tweaked jellyfish-high.png
    Manually tweaked jellyfish-high.png

    I (and you!) can automatically create the solid model of a matched cookie cutter and press:

    jellyfish-high - Cutter and Press - top view
    jellyfish-high – Cutter and Press – top view

    And then we can produce as many chunks of plastic as needed for our baking session!

    Printing that huge block of plastic did, however, uncover two longstanding mechanical problems. More tomorrow…

  • Return and Conquest of the Freezer Dog

    As expected, my crude bearing repairs on our Whirlpool refrigerator’s freezer fan didn’t last forever; the freezer dog crept back inside over the course of a few months. I recently ordered another replacement fan (yes, sixty bucks for an open-frame fan!), installed it, and have some interesting data points.

    The OEM fan in the Whirlpool refrigerator was made by FSP and has no country of origin. The date code on the winding insulation reports 1993 and it lasted for the better part of a dozen years.

    The replacement fan, which never sounded quite right and failed in short order, was made by Exact Replacement Parts and has no country of origin. I scrawled 2006 on it, although the bearing noise caused me to remove it almost immediately and re-fix the OEM fan bearings.

    The new fan is once again made by FSP, comes with Whirlpool logos on the screw-and-bushing kit bag, and sports Made In Mexico on the winding insulation. So far, it’s sounded OK, although the normal fan whir seems a bit louder & growlier than before. No howls, though, and that counts for a lot.

    I infer that the ERP fans weren’t entirely satisfactory, but that’s just a guess.

  • Ed’s High-Traction Pizza

    Our Larval Engineer, evidently planning to serve some genuine home-style pizza to her compadres, asked for the Official Recipe.

    It goes a little something like this…

    T minus 2.5 hours

    Blend (manually!) in mixer bowl:

    • 1 Tbsp    yeast (that’s two packets = crazy spendy → buy in bulk)
    • 1 Tbsp    brown sugar (or whatever sweet you have)
    • 1-1/2 C    warm water (1 minute in our microwave)

    Add on top of liquid:

    • 3 C    whole wheat flour
    • 1 C    white flour
    • 1 tsp    salt

    The original recipe called for:

    • 4 Tbsp    olive oil (or safflower, not vegetable / canola)
    • 1/2 C    additional flour only if you add oil

    Don’t stir, just pause 5 minutes until the yeast gets up & running.

    Run mixer until dough becomes rubbery and cleans the bowl.

    No mixer? Stir, stir, stir, then knead, knead, knead.

    Ed & Karen kneading bread dough - Raleigh 1995-ish
    Ed & Karen kneading bread dough – Raleigh 1995-ish

    (As you can see, she has experience kneading bread…)

    Cleave in twain, about 1 lb per lump.
    Oil mixer bowl & one lump, let rise.
    Flatten other lump in plastic bag & freeze for next week.

    Put 1 unit homebrew pizza sauce on counter to thaw.

    T minus 45 minutes

    Roll crust to fit pan, generously flour bottom, let rise on countertop.

    Grate cheese:

    • 2 oz    Sharp Provolone
    • 2 oz    Mozzarella
    • 3 oz    Monterey Jack

    Cube meat:

    • 2 oz    Ham
    • 4 oz    Turkey / pork / what have you

    Chop veggies:

    • handful    Broccoli tips (save stalks for tomorrow’s stir fry)
    • 1/2             Sweet pepper (Green / red)
    • 3                 Bunching onions (or small scallions, whatever)
    • 1 big          Mushroom (or 4 tiddly buttons)

    T minus 15 minutes

    Fire the Oven! to 500 F

    Flour bottom of crust, flop on pan
    Spread pizza sauce generously over crust, counter, walls, self
    Distribute meat / veggies
    Top with cheese

    Slide onto middle shelf of oven
    Set timer to 10 minutes if preheated, 12 minutes if not quite hot yet

    Clean utensils / counter / walls / self

    T minus zero

    Remove from oven (top should be brown & bubbling)
    Pause for coagulation
    Cut
    Distribute
    Nom on!

    The original recipe was about the same, plus foo-foo steps like putting oil in the dough, spreading cornmeal on the pan, oiling the crust before applying the sauce, and suchlike. You’ll need the book for all the details:

    The Complete Book of Pizza
    Louise Love
    Sassafras Press
    1980 (grin)

    I’m sure something different has come along in the last third of a century, but you’ll never hear it from me. Mostly, build a few, tweak the ingredients to suit your style / what’s on hand, and it’ll be all good.

    Enjoy…