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.
Things around the home & hearth
Earlier this year, I finally hauled a pile o’ scrap metal to the recycler. For future reference, here’s what clattered down on the scale:
I think the IRONY tag means ferrous bits & pieces in the mix. There’s a powerful motivation to hand them clean copper scrap, although I stop just after cutting off soldered pipe fittings and before stripping insulation.
Memo to Self: Next time, ask about PCBs and gold-plated connectors.
In the normal course of events, this critter would become an undistinguished brown moth:
Right now, it’s a two-day-old cross-striped cabbageworm. Its kin are voracious consumers of Brassicacae out in the garden and Mary’s raising it as a show-n-tell exhibit for her Master Gardener compadres; she advised it to not start any long novels.
Taken hand-held with the Pixel XL through a clip-on 10x macro lens.
Amazon may toss lithium cells into a cardboad box without much care, but chocolate requires attention to detail:
An ice pack, with a lump of ice in the middle, snuggled under the chocolate carton. The box arrived UPS Next Day from Amazon’s Kentucky distribution center, with the carton inside still cold to the touch.
On the average, I suppose, Amazon’s packaging averages out, but I’d rather they paid more attention to protecting hazardous material.
The picture shows a reenactment of actual events, because we were in the middle of something else when the UPS truck arrived.
So my trusty Sony DSC-H5 camera emitted a horrible crunching sound from inside its lens assembly, spat out several error codes which boiled down to “throw me out”, stopped retracting its lens, and developed a nasty rattle. If I thought dropping $2k on a fancy mirrorless DSLR would improve my photography, I’d do it, but instead I picked up a $60 used DSC-H5 from eBay and continued the mission.
Of course, the new-to-me H5 suffers from the half-press switch failure common to that entire line of Sony cameras; my DSC-H1 repair notes still come in handy for many folks.
I’d preemptively repaired the shutter button + switch in my now-defunct H5, so I dismantled it, extracted the control assembly + shutter button, bulldozed the debris aside, dismantled the new(er) H5, transplanted the parts, reassembled it, and declared victory.
Which left me with a pile of parts that could become an H5, if I could fix the lens assembly, which seemed unlikely. While pondering the futility of human existence, I applied a low-effort repair to the defunct shutter button by scuffing the nicely chromed and absurdly tapered tip of the OEM shutter button’s shaft, then applying a dot of JB Kwik epoxy:
The nice sphere came from hanging downward, with the button sitting atop a short brass tube on the workbench.
Filing the dot’s end flat produced a blunt plunger much larger than the OEM tip:
You can just see the edge of the OEM tip inside the grayish end, which puts the filed flat at the original pin’s length.
I punched a new plastic disk to replace the indented one:
Based on past experience, the new plunger tip will work fine, although, unlike the brass screw repair, the OEM plastic pin can still break and launch the spring-loaded shutter button cap into a nearby bush. Given that I may never actually use the repaired button, I’ll take the risk.
Finding out if the new tip will work may take a while:
I did a bit more disassembly than strictly necessary to replace the shutter button, but not by much; you’d be crazy to pay me to fix your camera, fer shure.
A pair of torchiere lamps lit the living room for many, many years:
During their tenure, they’ve gone from 100 W incandescent bulbs to “100 W equivalent” CFL curlicues to “100 W equivalent” warm-white LED bulbs. The LEDs aren’t up to the brightness of the original incandescents, but you can get used to anything if you do it long enough.
After so many years, the plastic shades / diffusers became brittle:
That’s after a bump, not a fall to the floor. So it goes.
Some casual searching didn’t turn up any likely replacements. The shade measures 14 inch = 355 mm across the top, far too large for the M2’s platform, but maybe a smaller shade in natural PETG would work just as well.
ACHTUNG! This is obviously inappropriate for the original incandescent bulbs and would be, IMO, marginal with CFL tubes. Works fine with LEDs. Your mileage may vary.
OpenSCAD to the rescue:
That’s a section down the middle. The top is 180 mm across, leaving 20 mm of general caution on the 200 mm width of the platform. The section above the sharply angled base is 90 mm tall to match the actual LED height, thereby putting them out of my line-of-sight even when standing across the room.
I ran off a short version, corrected the angles and sizes for a better fit, tweaked the thickness to fuse three parallel threads into a semitransparent shell, and …
Producing what looks like thin flowerpot required just shy of seven hours of print time, as it’s almost entirely perimeter, goin’ down slow for best appearance. The weird gold tone comes from the interaction of camera flash with warm-white CFL can lights over the desk.
If you hadn’t met the original, you’d say the new shade grew there:
It’s definitely a Brutalist design, not even attempting to hide its 3D printed origin and glorying in those simple geometric facets.
Those three threads of natural PETG makes a reasonably transparent plate, clear enough that the bulb produced an eye-watering glare through the shade:
So I returned it to the Basement Laboratory, chucked it up in the lathe (where it barely clears the bed), dialed the slowest spindle speed (150 rpm according to the laser tach, faster than I’d prefer), and slathered a thin layer of white-tinted XTC-3D around the inside:
For lack of anything smarter, I mixed 2+ drops of Opaque White with 3.1 g of Part A (resin), added 1.3 g of Part B (Hardener), mixed vigorously, drooled the blob along the middle of the rotating shade, spread it across the width using the mixing stick, smoothed it into a thin layer with a scrap of waxed paper, and ignored it for a few hours.
If the lathe perspective looks a bit weird, it’s perfectly natural: I raised the tailstock end enough to make the lower side of the shade just about horizontal. Given the gooey nature of XTC-3D, it wasn’t going anywhere, but I didn’t want a slingout across the lathe bed.
The lit-up result isn’t photographically different from the previous picture, but in person the epoxy layer produces a much nicer diffused light and no glare.
I might be forced to preemptively replace the other shade, just for symmetry, but we’ll let this one age for a while before jumping to conclusions.
The OpenSCAD source code as a GitHub Gist:
| // Torchiere Lamp Shade | |
| // Ed Nisley KE4ZNU – July 2017 | |
| /* [Build] */ | |
| Section = false; | |
| Shorten = false; | |
| //- Extrusion parameters – must match reality! | |
| /* [Hidden] */ | |
| ThreadThick = 0.25; | |
| ThreadWidth = 0.40; | |
| function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit); | |
| Protrusion = 0.01; | |
| HoleWindage = 0.2; | |
| //- Dimensions | |
| ID = 0; | |
| OD = 1; | |
| LENGTH = 2; | |
| /* [Dimensions] */ | |
| ShadeThick = 1.2; // perpendicular thickness | |
| BaseAngle = 42; // lamp base angle wrt vertical | |
| BaseTopDia = 131.0; // lamp ID at top | |
| ShadeBaseThick = 6*ThreadThick; // horizontal bottom thickness | |
| SeatDepth = 10.0 + ShadeBaseThick; // shade bottom to base top | |
| SeatDia = BaseTopDia – 2* SeatDepth / tan(BaseAngle); // lamp ID at seating depth | |
| ShadeTopDia = 180.0; // top OD, limited by printer platform width | |
| ShadeHeight = 90.0; // height above lamp base | |
| ShadeHoleDia = 36.0; // central hole dia | |
| ShadeAngle = atan(ShadeHeight / ((ShadeTopDia – BaseTopDia)/2)); | |
| echo(str("Shade angle: ",ShadeAngle)); | |
| ShadeHThick = ShadeThick / sin(ShadeAngle); | |
| echo(str(" horiz thickness:",ShadeHThick)); | |
| NumSides = 6*4; | |
| $fn = NumSides; | |
| //- Build it | |
| render(convexity=2) | |
| difference() { | |
| union() { | |
| cylinder(d1=SeatDia,d2=BaseTopDia,h=SeatDepth); // section within lamp base | |
| translate([0,0,SeatDepth]) | |
| cylinder(d1=BaseTopDia,d2=ShadeTopDia,h=ShadeHeight); | |
| } | |
| translate([0,0,SeatDepth]) // inside of upper shade | |
| cylinder(d1=BaseTopDia – 2*ShadeHThick, | |
| d2=ShadeTopDia – 2*ShadeHThick, | |
| h=ShadeHeight + Protrusion); | |
| translate([0,0,ShadeBaseThick]) // seating base | |
| cylinder(d1=SeatDia – 2*ShadeHThick, | |
| d2=BaseTopDia – 2*ShadeHThick, | |
| h=SeatDepth – ShadeBaseThick + Protrusion); | |
| translate([0,0,-Protrusion]) // socket clearance | |
| cylinder(d=ShadeHoleDia,h=2*ShadeHeight); | |
| if (Section) | |
| translate([0,-ShadeTopDia,0]) | |
| cube(2*ShadeTopDia,center=true); | |
| if (Shorten > 0) | |
| translate([0,0,(ShadeTopDia + 2*SeatDepth)]) | |
| cube(2*ShadeTopDia,center=true); | |
| } | |
This worked surprisingly well to lay out black foam gaskets for new fairing mounting plates:
Mary uses the Fons & Porter Mechanical Pencil to mark quilting patterns on fabric. It has, they say, a “strong ceramic 0.9MM white lead” with “water-soluble dyes” capable of both laying down a durable mark and washing out without leaving a trace. I don’t care about the latter, of course, but it did brush off reasonably well.
The next step involved running an X-Acto knife around the perimeter of the plate and punching the holes.
You can get colored ceramic leads (for small values of color) for use on other backgrounds.
Our long-suffering kitchen scale lost a pair of feet, most likely because those two feet do most of the skidding as we slide it onto a shelf below a cabinet. The scale has (well, had) six silicone rubber feet:
The vagaries of color photography turned a neutral-gray silicone disk into that weird blue.
A pair of ¼ inch disks punched from non-skid textured rubber tape fit perfectly into the recesses:
Now, we’ll see how tread adhesive withstands the same abuse.
The Smell of Molten Projects in the Morning 