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
A no-assembly-needed earplug case from Printables will be more easily found in Mary’s purse than the previous small bag:
That’s the “grippy bits” version of the model, which really is easier to open than the straight-sided version.
I printed a few more, loaded them with earplugs, and put them where they may come in handy. In retrospect, I should have used clear PETG to show off the retina-burn plugs.
Living in the future is great!
I long ago learned to never trust Amazon’s unit pricing (or, for that matter, their recommendations), so this came as no surprise:
OK, you generally don’t buy hoses “by the ounce”, but “per fluid ounce” may not mean what you think it means:
Pricing items individually should be simple, if you know what a single item is:
Even knowing the number of items and the overall price isn’t enough for Amazon to get it right:
Amazon now has a “shopping assistant”, so I asked Alexa why the unit prices were incorrect. After some back-and-forth providing details Alexa should have known from the context, this seemingly plausible sequence of words emerged:
Amazon apparently stopped commingling knockoff crap with brand-name products under the same SKU earlier this year, a change driven by major brands refusing to have anything to do with Amazon’s “supply chain”, but the probability of my one-by-one reports producing any discernible improvement seems low.
The Samsung dishwasher (model DW80K7050US/AA 03) that Came With The House fails immediately after entering the Dry part of the cycle: a relay in the control PCB under the door goes doink, all the LEDS go off then on again, the countdown timer stops changing, and that repeats as long as you like.
After considerable listening & pondering, I decided one event early in the Dry cycle involved starting a fan to vent the steam out of the interior. The wiring diagram shows the fan has a Fault wire: perhaps the fan has failed.
The maintenance manual shows different fans in three different places, although the control board has a connector for only one. By process of elimination, I found the fan atop the cabinet:
The cable from the fan in the vented compartment on the left burrows under the gray duct, around its back side, and plugs into the small white connector on the right. You must ease the cable from a row of hooks guiding it around the back of the duct, which requires slightly lifting the duct.
Unhook the two metal straps, remove four screws from the black vent, and lift it off the top to reveal the duct outlet pores:
Remove four more screws, lift the fan duct assembly just a little bit, and pry open three latches around the fan compartment with a consumer electronics case-cracking tool:
The new fan (on the right) looks very much like the OEM fan (on the left), even though it’s the $15 version rather than the $150 version you might buy from similar randomly named sellers if you were so inclined:
Detach the old fan & its cable, drop the new fan in place, snake its cable, plug its plug, and install All The Things in reverse order.
Unfortunately, after shoving the dishwasher back into its cubby, the new fan didn’t change the failure at all.
I hitched the old fan up to the bench supply and it spun just like it should. Wiring the Fault wire to a 5 V supply through a resistor shows it’s the usual tachometer signal pulsing as the rotor spins.
Which means the next step requires more pondering and PCB probing. The failure is too consistent to be a Heisenbug, but maybe something shook loose in there.
Two years ago I installed the DuckDuckGo browser on my phone and activated its app tracker blocking, which is basically a fake VPN swatting known tracker destinations out of the bitstream.
Somewhat to my surprise, the credit union’s app attempted to send my personally identifiable bits to a destination seemingly unrelated to any banking needs:
So I called up the credit union and asked:
Over the course of the next few weeks and many follow-up calls, I was told:
The intensity of the tracking attempts continued, even after disabling location sharing and not opening the app on any given day:
Eventually, I was told, in no uncertain terms:
They never did answer any of my original questions.
As I get very few checks in the mail, I have had little occasion to fire up the app since then.
The tracking continues apace, albeit with a different cast of characters:
You might think “The Trade Desk” has something to do with financial trading. You would be wrong.
I expect commercial banks to be even worse, so there’s nothing to be done.
Apart, of course, from blocking app tracking attempts with DuckDuckGo, using Firefox (with uBlock Origin) rather than Chrome, and running Pi-Hole on a Raspberry Pi for the home network. I admit my faith is touching.
In addition to printing bendy objects with TPU, the 0.8 mm nozzle 3D-prints PETG into thin walls with better transparency than the default 0.4 mm nozzle:
The wall is now 1.0 mm thick, rather than 0.6 mm, and is much closer to being transparent. Those gray links from the RPi camera mount inside the dishes help show the difference.
The 2.0 mm thick base plate is also more transparent, but mostly just reveals the 0.4 mm thick infill layers:
More study is needed, even if we already have far more soap dishes than strictly necessary.
For a square patio table (with one missing foot), of course:
These are chunky enough to demonstrate they’re made of clear-ish TPU, at least when backlit:
The interior of the leg determines what fits into it:
I pried out another foot, scanned it, and blew out the contrast:
Importing that into LightBurn let me draw a rectangle matching the measured size, then node-edit the corners to approximate the shape:
Export that shape as an SVG, import into OpenSCAD, and turn it into a solid model:
That’s the Show view simulating the actual positions, which demonstrates why the pair of legs at each corner wear mirror-imaged feet. The Build view arranges the pair more sensibly for 3D printing:
The protrusions and their bumps went through several iterations on the way to being functional, with the black TPU prototype on the left being entirely too bendy and the first clear version requiring utility knife editing to fit the end posts inside the leg:
The original feet seem to be injection-molded ABS with a flat bottom intended to erode one corner against whatever the table stands on. However, the legs splay out at 5° from the vertical, which makes the flat bottom I used for the first few iterations obviously wrong:
Somebody who can math harder than I would resolve the two angles and all the measurements into a single transformation matrix, but I rotated the foot separately around the X and Y axes, trigged the lowest corner to the proper height, then chopped off everything below Z=0. Works for me.
The OpenSCAD source code as a GitHub Gist:
| // Patio Table Foot – rectangular legs | |
| // Ed Nisley – KE4ZNU | |
| // 2026-05-26 | |
| include <BOSL2/std.scad> | |
| Layout = "Show"; // [Show,Build] | |
| /* [Hidden] */ | |
| HoleWindage = 0.2; | |
| Protrusion = 0.01; | |
| NumSides = 4*3*2*4; | |
| Gap = 5.0/2; | |
| $fn=NumSides; | |
| PadOA = [50,23.5,4.5]; | |
| LegAngles = [5,5]; | |
| EndStrut = [2.5 + 2.5,13.3 – 1.0,23.0]; | |
| SideStrut = [12.0,5.5 – 1.0,13.0]; | |
| Clearance = 0.5; | |
| StrutsOC = [44.0 – EndStrut.x,18.0 – SideStrut.y]; | |
| //—– | |
| // Define it | |
| module Foot(angles = LegAngles) { | |
| difference() { | |
| up((PadOA.x/2)*abs(sin(angles.x)) + (PadOA.y/2)*abs(sin(angles.y))) | |
| xrot(angles.x) yrot(angles.y) | |
| union() { | |
| down(3*PadOA.z) | |
| linear_extrude(4*PadOA.z) | |
| left(PadOA.x/2) fwd(PadOA.y/2) | |
| import("Patio Table Foot – pad outline.svg",center=true); | |
| up(PadOA.z) | |
| for (i = [-1,1]) | |
| right(i*StrutsOC.x/2) | |
| cuboid(EndStrut,anchor=BOTTOM) position(TOP) | |
| down(EndStrut.y/2) left(i*Clearance) | |
| pie_slice(r=(PadOA.x – StrutsOC.x)/2,ang=180,l=EndStrut.y,anchor=CENTER,spin=-i*90,orient=FRONT); | |
| up(PadOA.z) | |
| for (j = [-1,1]) | |
| fwd(j*StrutsOC.y/2) | |
| cuboid(SideStrut,anchor=BOTTOM) position(TOP) | |
| down(SideStrut.x/2) zrot(90) right(j*Clearance) | |
| pie_slice(r=(PadOA.y – StrutsOC.y)/2,ang=180,l=SideStrut.x,anchor=CENTER,spin=j*90,orient=FRONT); | |
| } | |
| cuboid(4*PadOA,anchor=TOP); | |
| } | |
| } | |
| //—– | |
| // Build it | |
| if (Layout == "Show") { | |
| back(PadOA.y/2 + Gap) | |
| Foot(); | |
| left(0.8*PadOA.x) fwd(PadOA.y) zrot(-90) | |
| yflip() Foot(); | |
| } | |
| if (Layout == "Build") { | |
| union() { | |
| fwd(PadOA.y/2 + Gap) | |
| Foot(); | |
| back(PadOA.y/2 + Gap) | |
| yflip() Foot(); | |
| } | |
| } |
For a round patio table, although you can’t tell from the picture:
Also despite appearances, that’s 3D printed from clear-ish TPU, with its black appearance due to internal reflections from the leg’s dark interior.
The original hard-white-plastic feet had eroded enough to let the aluminum legs scrape the deck paint:
The only way to extract each old foot was to hack out a segment with a razor knife, after which it slid out easily.
The ring around the top of the sections provides enough griptivity inside the leg to hold the foot in place:
As with the TPU chains on the bike rack tray holder, I expect the compressed / bent segments will gradually relax inside the legs, but the feet ought not fall out in normal use.
The OpenSCAD source code isn’t quite a one-liner, but it’s close:
// Patio Table Foot - round legs
// Ed Nisley - KE4ZNU
// 2026-05-29
include <BOSL2/std.scad>
/* [Hidden] */
ID = 0;
OD = 1;
LENGTH = 2;
HoleWindage = 0.2;
Protrusion = 0.01;
NumSides = 4*3*2*4;
Gap = 5.0;
$fn=NumSides;
PadOA = [8.0,1*INCH,3.0];
SleeveOA = [13.0,21.7 - HoleWindage,12.0];
Kerf = 2.5;
//-----
// Build it
difference() {
union() {
tube(PadOA[LENGTH],od=PadOA[OD],id=PadOA[ID],anchor=BOTTOM) position(TOP)
tube(SleeveOA[LENGTH],od=SleeveOA[OD],id=SleeveOA[ID],anchor=BOTTOM);
up(PadOA[LENGTH] + SleeveOA[LENGTH] - 1.0)
torus(d_maj=SleeveOA[OD],r_min=(PadOA[OD] - SleeveOA[OD])/2,anchor=TOP);
}
up(PadOA[LENGTH])
for (a = [0,60,120])
zrot(a)
cuboid([PadOA[OD],Kerf,2*SleeveOA[LENGTH]],anchor=BOTTOM);
}
The Smell of Molten Projects in the Morning 