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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

Bird Feeder Tray Mount

The mixed flock attending the bird feeder in the back yard scatters enough seeds to attract the deer, so I added a tray underneath to catch the overspray:

Well, two trays, because it took a couple of iterations to make the solid model match reality:

Bird Feeder Tray Mount - show layout — Bird Feeder Tray Mount – show layout

The n-1 iteration was Close Enough™ and two trays are obviously better than one.

The “trays” are stray lids from the six gallon buckets we use for many purposes, including root-cellaring the vegetable garden harvest. The lid’s solid model was straightforward:

Bird Feeder Tray Mount - lid model — Bird Feeder Tray Mount – lid model

Removing the lid from a solid block produces the most complex part of the mount:

Bird Feeder Tray Mount - mount layout — Bird Feeder Tray Mount – mount layout

An aluminum plate on the outside (the gray slab in the overall view above) distributes the strain from the two M6 screws across the block.

A smaller block on the inside of the lid has a pair of square nuts:

Bird Feeder Tray Mount - segment layout — Bird Feeder Tray Mount – segment layout

All three parts build from their flattest side:

Bird Feeder Tray Mount - build layout — Bird Feeder Tray Mount – build layout

The downward facing clamp arch in the main block didn’t need support, but the square nut sockets in the segment definitely came out better with little support blocks inside; PrusaSlicer does a good job with most support structures.

The n-1 iteration used M6 rivnuts that were slightly too long after making the lid model match reality, so I switched to square nuts. The OpenSCAD code calculates the segment block length to match the actual screws, but 75 mm M6 screws and square nuts are barely long enough.

I clamped the outer block to the lid as a drill guide for the first hole, then pinned the block with a screw to ensure it didn’t slip while drilling the second hole:

Bird Feeder Tray Mount - drilling setup — Bird Feeder Tray Mount – drilling setup

Those were freehanded in the drill press at low speed with serious concentration; some things you just gotta do that way.

The mixed flock overwhelmingly approves the trays, to the extent a dozen birds clamor to use them: definitely a crowd-pleaser!

I’m certain you can buy pole-mounted trays, but what’s the fun in that?

The OpenSCAD source code as a GitHub Gist:

	// Bird feeder tray mount
	// Ed Nisley – KE4ZNU
	// 2025-11-06

	include <BOSL2/std.scad>

	Layout = "Show"; // [Build,Show,Lid,Mount,Segment,Nut]

	/* [Hidden] */

	ID = 0;
	OD = 1;
	LENGTH = 2;

	HoleWindage = [0.2,0.2,0.2];
	Protrusion = 0.1;

	NumRibs = 12; // stiffening ribs
	NumSides = 8*NumRibs;

	$fn=NumSides;

	Gap = 5.0;

	WallThick = 9.0; // robust walls
	Kerf = 1.0; // clamp cut
	TapeThick = 0.5; // wrap around pole

	LidOD = 12; // main diameter in inches

	PoleOD = 1*INCH;

	PlateThick = 2.0; // backing plate for clamp

	Screw = [6.0,12.0,6.0]; // thread OD, washerOD, head
	ScrewLength = 75.0;

	ScrewOC = 60.0; // chosen to clear stiffening ribs in lid

	LidLayers = [ // bottom to top, ID = 0 means solid disk, LENGTH = exterior measurement
	[0,(LidOD-2(3/8))INCH,Protrusion], // 0 – below zero to prevent Z fighting
	[0,(LidOD-2(3/8))INCH,(3/8)*INCH], // 1 – base inside bucket
	[0,(LidOD+2(1/8))INCH,(1/8)*INCH], // 2 – flange
	[(LidOD-2(1/2))INCH,LidODINCH,(7/8)INCH], // 3 – sealing ring
	];

	LidOAH = LidLayers[1][LENGTH] + LidLayers[2][LENGTH] + LidLayers[3][LENGTH];
	LidTopDepth = (3/4)*INCH; // from highest part of interior

	MountBlockWidth = ScrewOC + 2*WallThick;

	BaseSagitta = LidLayers[1][OD]/2 – sqrt((LidLayers[1][OD]/2)^2 – (MountBlockWidth^2)/4);
	echo(BaseSagitta=BaseSagitta);

	PoleOffset = BaseSagitta + ((LidLayers[2][OD] – LidLayers[1][OD])/2) + WallThick + PoleOD/2;

	MountBlock = [PoleOffset + PoleOD/2 + WallThick – PlateThick,MountBlockWidth,LidOAH];
	echo(MountBlock=MountBlock);

	SegBlockOffset = ScrewLength – MountBlock.x – PlateThick; // assumes recessed
	SegmentBlock = [2*SegBlockOffset,MountBlock.y,LidTopDepth];

	Rib = [2*6.0,5.0,LidTopDepth]; // lid stiffening ribs
	RibAlign = 0 * 180/NumRibs; // position ribs wrt mount

	EdgeRadius = 3.0;

	//—–
	// Rivnut
	// The model collects all the magic numbers right here

	/*
	RivnutOAL = 15.0;

	module Rivnut() {

	union() {
	cyl(1.6,d=13.0,circum=true,anchor=BOTTOM);
	cyl(RivnutOAL,d=9.0,circum=true,anchor=BOTTOM);
	}

	}

	*/

	//—–
	// Square nut
	// The model collects all the magic numbers right here

	NutOAL = 5.0;

	module SquareNut() {

	cuboid([10.0,10.0,5.0],anchor=BOTTOM);

	}
	//—–
	// Bucket lid
	// Centered at XY=0, Z=0 at top of exterior flange

	module BucketLid(Interior=true,Expand=false) {

	render()
	union() {
	down(LidLayers[2][LENGTH])
	cyl(LidLayers[1][LENGTH],d=LidLayers[1][OD],anchor=TOP);
	cyl(LidLayers[2][LENGTH],d=LidLayers[2][OD],anchor=TOP);
	if (Interior) {
	if (false)
	down(Expand ? Protrusion : 0)
	tube(LidLayers[3][LENGTH] + (Expand ? 2*Protrusion : 0),
	id=LidLayers[3][ID],od=(Expand ? 2 : 1)*LidLayers[3][OD],anchor=BOTTOM);
	else
	difference() {
	cyl(LidLayers[3][LENGTH] + (Expand ? 2*Protrusion : 0),
	d=(Expand ? 2 : 1)*LidLayers[3][OD],anchor=BOTTOM);
	up(LidLayers[3][LENGTH] – LidTopDepth)
	cyl(LidTopDepth + (Expand ? 2*Protrusion : 0),
	d=LidLayers[3][ID],anchor=BOTTOM);
	}
	up(LidLayers[3][LENGTH] – LidTopDepth)
	for (i=[0:(NumRibs – 1)])
	zrot(i*360/NumRibs + RibAlign)
	right(LidLayers[3][ID]/2)
	cuboid(Rib,anchor=BOTTOM,rounding=1,edges="Z");
	}
	else
	down(Expand ? Protrusion : 0)
	cyl(LidLayers[3][LENGTH] + (Expand ? 2*Protrusion : 0),
	d=(Expand ? 2 : 1)*LidLayers[3][OD],anchor=BOTTOM);
	}
	}

	// Mount clamp

	module Mount() {
	render()
	difference() {
	cuboid(MountBlock,anchor=BOTTOM+LEFT,rounding=EdgeRadius,edges="X");
	left(LidLayers[1][OD]/2 – BaseSagitta)
	up(LidLayers[1][LENGTH] + LidLayers[2][LENGTH])
	BucketLid(Interior=false);
	right(PoleOffset) {
	cyl(3MountBlock.z,d=(PoleOD + HoleWindage.x + 2TapeThick),circum=true,anchor=CENTER);
	cuboid([Kerf,2MountBlock.y,3MountBlock.z]);
	}
	if (false)
	right(MountBlock.x – PlateThick)
	cuboid(3*[PlateThick,MountBlock.y,MountBlock.z],anchor=LEFT);
	up(LidOAH – LidLayers[3][LENGTH]/2)
	for (j=[-1,1])
	fwd(j*ScrewOC/2) {
	cyl(ScrewLength,d=Screw[ID] + HoleWindage.x,circum=true,orient=RIGHT,anchor=BOTTOM,$fn=6,spin=180/6);
	if (false)
	right(MountBlock.x + Protrusion)
	cyl(Screw[LENGTH] + Protrusion,d=Screw[OD] + HoleWindage.x,circum=true,
	orient=LEFT,anchor=BOTTOM,$fn=12,spin=180/12);
	}
	}
	}

	// Nut block segment inside lid

	module NutSegment() {

	render()
	difference() {
	cuboid(SegmentBlock,anchor=BOTTOM,rounding=EdgeRadius,edges="X");
	down(LidLayers[3][LENGTH] – LidTopDepth)
	left(LidLayers[1][OD]/2 – BaseSagitta)
	BucketLid(Interior=true,Expand=true);
	up(LidTopDepth – LidLayers[3][LENGTH]/2)
	for (j=[-1,1])
	fwd(j*ScrewOC/2) {
	left(SegmentBlock.x/2)
	cyl(ScrewLength,d=Screw[ID],circum=true,anchor=BOTTOM,$fn=6,spin=180/6,orient=RIGHT);
	left(SegmentBlock.x/2)
	yrot(90)
	SquareNut();
	}
	}

	}

	//—–
	// Build things

	if (Layout == "Lid")
	BucketLid();

	if (Layout == "Mount")
	Mount();

	if (Layout == "Segment")
	NutSegment();

	if (Layout == "Nut")
	Rivnut();

	if (Layout == "Show") {
	down(LidLayers[1][LENGTH] + LidLayers[2][LENGTH]) {
	Mount();
	color("Orange",0.5)
	up(LidOAH – LidLayers[3][LENGTH]/2)
	right(MountBlock.x + PlateThick)
	for (j=[-1,1])
	fwd(j*ScrewOC/2)
	cyl(ScrewLength,d=Screw[ID],circum=true,orient=LEFT,anchor=BOTTOM);
	}
	up(LidLayers[3][LENGTH] – LidTopDepth)
	NutSegment();

	color("Gray",0.4)
	right(PoleOffset)
	cylinder(3*MountBlock.z,d=(PoleOD),anchor=CENTER);
	color("Gray",0.4)
	left(LidLayers[1][OD]/2 – BaseSagitta)
	BucketLid();
	color("White",0.7)
	down(LidLayers[1][LENGTH] + LidLayers[2][LENGTH])
	right(MountBlock.x + 2*PlateThick)
	difference() {
	cuboid([PlateThick,MountBlock.y,MountBlock.z],anchor=BOTTOM+LEFT,rounding=EdgeRadius,edges="X");
	up(LidOAH – LidLayers[3][LENGTH]/2)
	for (j=[-1,1])
	fwd(j*ScrewOC/2)
	cyl(ScrewLength,d=Screw[ID],circum=true,orient=RIGHT,anchor=CENTER);
	}
	}

	if (Layout == "Build") {
	render()
	union() {
	difference() {
	left(MountBlock.z + Gap/2)
	up(PoleOffset – Kerf/2)
	yrot(90)
	Mount();
	cuboid([3MountBlock.z,2MountBlock.y,3*MountBlock.x],anchor=TOP);
	}
	render()
	right(Gap/2)
	intersection() {
	up(MountBlock.x)
	yrot(90)
	Mount();
	up(MountBlock.x – PoleOffset)
	right(MountBlock.z/2)
	cuboid([2MountBlock.z,2MountBlock.y,MountBlock.x],anchor=TOP);
	}
	right(2*MountBlock.z – BaseSagitta)
	up(SegmentBlock.x/2)
	yrot(-90)
	NutSegment();
	}
	}

view raw Bird Feeder Tray Mount.scad hosted with ❤ by GitHub

2025-11-19

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
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
Garden Knife Sheath Redux

A knife found in Mary’s Bucket o’ Gardening Gear was in need of a sheath:

Serrated Garden Knife

Unlike the time before or the time before that, a few minutes with LightBurn laid out the overall pattern:

Garden Knife Sheath – LightBurn layout

The knife’s silhouette came from a few minutes with GIMP, because cleaning up the edges on a graphics tablet is easier than fiddling with precise spline curves. Export the selection as an SVG, import into LightBurn, set to Fill, and Fire The Laser:

Garden knife sheath

The upper block in the LightBurn layout is an oversized rectangle so I could cut that out first, stick craft adhesive on both sides, trim the edges, drop it back into the hole, then cut the middle part of the sheath.

It’s made of recycled through-dyed chipboard and it won’t last forever, but that’s not a problem because these things tend to wander off before they disintegrate.

I must do a few more for the other garden bucket, but those should be straightforward.

2025-11-10
Silicone Handle Wrap

The common fate of all “soft touch” silicone handles is to become sticky and gooey. While some goo may be removable, I’ve found that wrapping self-bonding silicone tape around the mess both encapsulates it and maintains the grippiness of the original silicone.

The most recent casualty is the decade-old ceramic crysknife I returned to service while the rest of the knives were being sharpened:

Ceramic knife – silicone handle wrap

While I was at it, I added griptivity to the leaf blower handle:

Leaf blower – silicone handle wrap

Long years ago, before getting transparent silicone tape, I’d wrapped a kitchen slotted spoon:

Kitchen spoon – silicone handle wrap

Stipulated: Butt-ugly and built to stay that way.

Oddly, the handle on the matching spatula / scraper remains non-gooey to this day.

Should you care more about form than function, this repair is not the one you seek …

2025-11-06
Amazon Basics Alkaline AA Cell Failures

A few weeks ago, the house seemed unusually warm when I crawled out of bed. Checking the heat pump thermostat woke me right up:

Heat pump – battery critical

This, as they say, is not a nominal outcome.

A pair of AA alkaline cells powers the thermostat and, due to its wireless communication link to the heat pump’s air handler in the attic, it chews through two pairs a year. As you’d expect, it displays a “Battery Low” message for at least few days at the end of their lifetime, which was not the case for this failure.

After replacing the cells, the thermostat reported that, yes indeed, the house was much warmer than usual:

Heat pump – high temperature

A temperature monitor showed the heat had jammed on in the deep of the night:

Heat pump – runaway temperature

The heat pump exhaust temperature showed a similar event:

Heat pump – exhaust temperature

One of the AA cells showed about 1.3 V, but the other was around 0.25 V, suggesting an abrupt failure, rather than the normal gradual voltage decrease with plenty of time to replace the cells.

It’s reasonable to jam the heat on when the thermostat isn’t communicating, rather than let the house gradually freeze, but it did come as a surprise. I don’t know how the heat pump reacts to a battery failure during the cooling season; not refrigerating the house would be perfectly fine in most circumstances.

The Amazon Basics AA cells I’ve been using have worked as well as the Name Brand ones, so I was willing to write one off as happenstance.

However, during the recent Daylight Saving Time dance, I discovered the clock in Mary’s Long Arm Sewing Room had stopped, with an Amazon Basics AA alkaline cell from the same lot inside:

Failed clock AA cell

The date shows I’d replaced it in March, with the previous cell lasting an amazing 3-½ years. This one was completely dead, reading barely 0.1 V, after seven months. Mary hasn’t had a quilting project at the long-arm stage in recent months, so the clock may have been stopped for quite a while.

Perhaps something has gone badly wrong with Amazon’s battery supplier QC.

As the saying goes: Once is happenstance. Twice is coincidence. Three times is enemy action.

2025-11-04