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.

Tag: Improvements

Making the world a better place, one piece at a time

AC Power / Energy Meter

A surprisingly competent AC power-line voltage / current / energy / power meter fits neatly into a mud ring atop a 4×4 inch square electrical box:

AC Power Meter – assembled

The inside view shows the wiring, such as it is:

AC Power Meter – interior

The square black block is the split-core current transformer around the hot line wire, which sticks up just enough in any orientation to require an extension ring, thus a second trip to the Big Box store.

The mud ring has two tabs with threaded screw holes for the device (switch / GFCI / whatever): grab those with a Vise-Grip, flex until they break off, then file down the stub.

Generous globs of hot-melt glue secure the meter in the mud ring. I added a strip of duct tape under the connections in the hope it might avert disaster should either of the AC wires come loose, but my real hope is in the safety ground to the metal box.

The line cord comes from the Box o’ IEC cords, minus its IEC connector, plus the bright yellow USA-ian connector.

Yes, the three metal box pieces and the Leviton connector cost far more than the meter.

Not to code, but good enough for my purposes.

2025-11-18
PolyDryer Box Desiccant Tray

Having used desiccant in tea bags inside the PolyDryer boxes with some success, I wanted to see what happens with more exposed surface area:

Polydryer Box desiccant tray – installed

The tray (jawbreaker boxes.py URL) is 2 mm chipboard with a quartet of additional notches fitting the protrusions in the bottom of the Polydryer box:

Polydryer Box desiccant tray – assembly

Although you’ll find plenty of printed trays, many with ingenious perforated lids, this was quick & easy:

Polydryer Box desiccant tray – cutting

They’re painfully prone to dumping their contents, despite the dividers which are intended to dissuade the beads from taking collective action and surging over the slightly higher outer walls. Fortunately, the dump occurs inside a sealed box and is entirely survivable.

Distributing 25 g of silica gel neatly fills the sections:

Polydryer Box desiccant tray – top view

Now it’s just a matter of time …

2025-11-17
Dryer Vent Filter Snout: TPU Warp

Making the clothes dryer vent filter snout from TPU did not work nearly as well as I expected:

Clothes Dryer Vent Filter Snout – TPU warp

I think that’s the result of applying heat to a slightly compressed rear wall made of bendy plastic.

Making it from much stiffer white PETG required moving the front mounting tabs to the middle to allow enough bendiness to snap them into the vent:

Clothes Dryer Vent Filter Snout – slicer

Although both pieces barely fit on the MK4’s platform, I made the upper ring first to verify the fit:

Clothes Dryer Vent Filter Snout – slicer

If I ever make another, it’ll print as a single top-side-down unit, because the dimensions are now spot on.

From outside, it looks just like the TPU version:

Clothes Dryer Vent Filter Snout – PETG installed

The snood is a cheesecloth tube with shock cord holding it to the snout.

2025-11-14
Humidifier Caster Feet

The ancient and much–repaired Sears humidifier works better in its new location across the living room with its front raised a few millimeters, which may have something to do with its plastic housing supporting a pair of heavy water containers for a few decades.

After fiddling around with shims to find the proper height, these feet descended from the Husky workbench feet:

Humidifier Caster Feet – installed

They’re glued up from 3 mm plywood sitting on a 1 mm layer of cork:

Humidifier Caster Feet – clamping

The humidifier seems much happier with its casters 4 mm above the floor. Seems awfully fussy to me, but there’s no arguing with success.

2025-11-13
Tour Easy: Garage Door Remote Mount

It turns out that keeping the garage door remote clipped to the starboard underseat pack on my Tour Easy attenuated its RF enough that even the directed receiver antenna couldn’t grab enough signal until I rolled onto the end of the driveway.

While contemplating what’s involved in making a 3D model of the remote’s curved backside, I realized the bike already had a perfect spot:

Tour Easy Zzipper Fairing – block mount

A few strips of good outdoor-rated foam tape later:

Tour Easy – garage door opener mount

Believe it or not, the camera is looking through the year-old and unwashed fairing on my bike.

Stipulated: aligning the PCB antenna flat against a small aluminum plate atop a bunch of aluminum bars isn’t perfect. However, enough RF wriggles out to trigger our opener from four houses down the hill, giving it plenty of time to haul the door out of my way.

That was trivial …

2025-11-12
DIY Birdsavers

Mary counts birds for Project Feederwatch and the feeder goes up at Halloween, whereupon birds begin smashing against the windows. Having bought a lifetime supply of paracord for this purpose on our previous house, I made a DIY Birdsaver for the rear windows:

DIY Birdsavers – interior view

This project was tremendously simplified by discovering the soffits consist of molded PVC sheets having exactly the proper 4 inch spacing and a convenient lip perfectly suited to capture the knot:

DIY Birdsavers – soffit mount

So far, no thuds …

2025-11-11
Generator Air Filter Screw Knob
Part of the Autumn festivities around here involves blowing leaves into piles, then shredding them into garden mulch. Given that I have a plug-in electric leaf blower / wind stick, I use this as an excuse to exercise the emergency generator (similar to that one) with a (relatively) short extension cord.

As with all small gasoline engines, I fire a shot of starting fluid into the air cleaner to reduce the number of engine-start yanks, which means I must remove the generator’s side panel and unscrew the filter cover. For years I have sworn mighty oaths on the bones of my ancestors to knobify that screw, thus eliminating fiddling with a screwdriver.

Finally:

Generator Air Filter Screw Knob – solid model

A dozen minutes of printing and a snippet of good double-sided tape later:

Generator air filter knob – installed

The knob sticks out far enough to push into the foam “sound deadening” liner on the cover, so it won’t vibrate loose.

The OpenSCAD source code:
```
include <BOSL2/std.scad>

/* [Hidden] */

HoleWindage = 0.2;
Protrusion = 0.1;

// Screw head dome

HeadHeight = 2.0;
HeadOD = 14.75;

DomeRadius = (HeadHeight^2 + (HeadOD^2)/4) / (2*HeadHeight);
echo(DomeRadius=DomeRadius);

KnobOD = HeadOD;
KnobLength = 15.0;

RimFudge = 0.3;   // ensures a printable edge

// Build it

difference() {
  cyl(h=KnobLength, r=KnobOD/2,anchor=BOTTOM,texture="trunc_pyramids",tex_size=[2.0,KnobLength/4]);
#  up(KnobLength - HeadHeight + RimFudge)
    spheroid(r=DomeRadius,circum=true,style="icosa",anchor=BOTTOM);
}
```
The cover has robust plastic latches, so I haven’t ever bothered to tighten those screws.
2025-11-07