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.
Other creatures in our world
We’ve seen several new rabbits munching greenery in the back yard, but this little one may be studying auto repair under our neighbor’s car:
Unlike mice, even a small rabbit won’t take up residence in the air cleaner.
The weird granulated look comes from a Pixel 6a camera zoomed all the way tight through two layers of 1960-era window glass at an acute angle. The bad camera you have is always better than the good camera you don’t.
A critter made off with our battered plastic rain gauge, so I set up an Ambient Weather WS-5000 station to tell Mary how much rain her garden was getting. I added the Official Bird Spike Ring around the rain gauge to keep birds off, but robins began perching atop the anemometer while surveying the yard and crapping on the insolation photocell.
After a few false starts, the anemometer now has its own spikes:
It’s a snugly fitting TPU ring:
The spikes are Chromel A themocouple wire, because a spool of the stuff didn’t scamper out of the way when I opened the Big Box o’ Specialty Wire. As you can tell from the picture, it’s very stiff (which is good for spikes) and hard to straighten (which is bad for looking cool).
The shape in the middle is a hole diameter test piece. Next time around, I’ll use thicker 14 AWG copper wire:
The test piece showed I lack good control over the TPU extrusion parameters on the Makergear M2, as holes smaller than about 2 mm vanish, even though the block’s outside dimensions are spot on. This application wasn’t too critical, so I sharpened the wire ends and stabbed them into the middle of the perimeter threads encircling the hole.
Now we’ll discover how TPU survives weather.
The OpenSCAD source code as a GitHub Gist:
| // Ambient Weather – Ambient Weather WS-5000 anemometer bird spike ring | |
| // Ed Nisley – KE4ZNU | |
| // 2025-06-09 | |
| include <BOSL2/std.scad> | |
| Layout = "Show"; // [Show,Build,Slice] | |
| /* [Hidden] */ | |
| HoleWindage = 0.2; | |
| Protrusion = 0.1; | |
| ID = 0; | |
| OD = 1; | |
| LENGTH = 2; | |
| SpikeOC = 30.0; // straight-line distance between spikes, OEM = 35 | |
| WallThick = 4.0; | |
| BandID = 3.5*INCH – 0.5; // = OD of weather station | |
| BandOD = BandID + 2*WallThick; | |
| BandHeight = 8.0; | |
| SpikeOD = 1.7 + HoleWindage; // wire diameter | |
| SpikeWall = 2.0; // around wires | |
| SpikeBCD = BandOD; | |
| MountOD = SpikeOD + 2*SpikeWall; | |
| NumSpikes = ceil(PI*BandOD/SpikeOC); // need integral number of spikes | |
| SpikeAngle = 360/NumSpikes; | |
| NumSides = 3*NumSpikes; | |
| echo(SpikeAngle=SpikeAngle); | |
| echo(NumSpikes=NumSpikes); | |
| //———- | |
| // Define Shapes | |
| module Slice() { | |
| difference() { | |
| hull() { | |
| pie_slice(h=BandHeight,d=BandOD,$fn=NumSides,ang=SpikeAngle,spin=-SpikeAngle/2,anchor=BOTTOM); | |
| right(SpikeBCD/2 – MountOD/2) | |
| cyl(h=BandHeight,d=MountOD,realign=true,anchor=LEFT+BOTTOM,$fn=2*6); | |
| } | |
| down(Protrusion) { | |
| cyl(h=BandHeight + 2*Protrusion,d=BandID,$fn=NumSides,circum=true,realign=true,anchor=BOTTOM); | |
| right(SpikeBCD/2) | |
| cyl(h=BandHeight + 2*Protrusion,d=SpikeOD,$fn=6,circum=true,realign=true,anchor=BOTTOM); | |
| } | |
| } | |
| } | |
| module SpikeRing() { | |
| for (i=[0:NumSpikes-1]) | |
| zrot(i*SpikeAngle) | |
| Slice(); | |
| } | |
| //———- | |
| // Build things | |
| if (Layout == "Slice") { | |
| Slice(); | |
| } | |
| if (Layout == "Show") { | |
| left(SpikeBCD/2) | |
| Slice(); | |
| SpikeRing(); | |
| } | |
| if (Layout == "Build") { | |
| SpikeRing(); | |
| } |
Last year, a pair of finches made several nesting attempts in the wreath at our front door, only the first of which succeeded.
This year, a pair of robins took over:
They’re considerably larger and we hoped would be more able to repel attackers. They also seemed to get off to a late start, as we saw young robins hopping around the yard with other adults while these birds were building their nest, so this may have been their second nest of the season.
The first egg appeared on 5 May:
Two weeks later, the first chick pipped:
Only a mother could love something like that, but they almost always do:
Floppy chicks are (still) floppy one day later:
Rapid growth is Job One:
Taking shape:
And then there were none:
The M50 trail camera was defunct, so we don’t know what happened to them. Mary didn’t hear a fuss through the adjacent bedroom window, which suggests something grabbed them while Ms Robin was off getting breakfast.
We took the wreath down and replaced it with a slate plaque, because we’d rather not know …
A bird box from long ago emerged from the heap and took its place in an upstairs window:
That big open back held an acrylic sheet letting us watch wrens raise their family; snugging it against the window makes that sheet superfluous. We’re hoping to lure the Wreath Finches from their preferred spot by the front door, but we’re open to any birds in need of a nesting spot.
The aluminum angle formerly securing the box to various wood window frames wasn’t going to work here, so I conjured a pair of rotating T-nuts to fit the track in the plastic window frame:
They’re made from a 5/16-18 T-nut and two layers of 3 mm plywood, all glommed together with E6000-Plus adhesive because it did not scamper out of the way when I opened the Adhesives Cabinet.
Some doodling convinced me a pair of quarter-circles welded back-to-back, minus cutouts for the metal T-nuts, would suffice:
The radius must be a little less than the width of the opening into the channel (20 mm) and the diameter must be a little more than the width of the channel behind that opening (32-ish mm), so I picked 17 mm. The metal T-nut flange is just over 20 mm, but the spike cutouts (omitted from the LightBurn layout) let it slip through the opening.
A random block of wood positions the box away from the frame enough to clear the outermost flange carrying the screen. Drilling oversize ⅜ inch holes countersunk the top of the T-nut into the block and eliminated excessive alignment fussiness.
Slicing 20 mm off the bolts fit them into the space available, with a pair of stainless washers covering the gaps.
A doodle with measurements you won’t need, but surely handy for mounting something else around here:
Now, to see who takes up residence …
The larger vole trap boxes didn’t survive the early spring rainfall, so we decided to upgrade the fleet with more durable boxes:
I obviously need a larger light box.
The trap boxes come in 7 quart and 3.5 quart sizes, although we expect either will comfortably accommodate a single vole.
They’re made of polypropylene plastic eminently suited for laser cuttery, so I borrowed the holes from the cardboard box setup:
The clamps on the knife bars held the angle block and boxes in pretty much the same position, so I didn’t realign anything after figuring out a pair of magnets would hold the lid to the angle:
The box side is slightly sloped, so I probably should have angled the block to tilt the lid, but this isn’t a precision job:
The white smudges on the lid come from vaporized polypropylene:
The body count thus far is just one field mouse, but the season is yet young.
As the poster says, “Until you spread your wings, you’ll have no idea how far you can walk”:
My feet get chilly just looking:
We think the flock has a Rules Compliance Officer who gave one miscreant goose an all-around inspection:
Just another day at the office …
The WordPress AI generated an excerpt for this post:
The poster emphasizes potential discovery through exploration, while the goose flock exhibits curiosity, hinting at humorous governance among them at Vassar Sunset Lake.
I had no idea “governance” was a goose thing.
A highly effective way to bait a rat trap for garden voles:
The trap is a Victor M205 (in a 12-pack as M326) with a big yellow plastic bait pedal. The bait is pieces of walnut, secured to the pedal with generous strands of hot melt glue. The trick involves mechanically capturing the walnut by slobbering glue over & around it, forcing the vole to pull & tug while gnawing the last bit of goodness.
Which generally ends badly:
I do not begrudge the critters a fancy last meal; it’s gotta be better than their usual diet of carrots / radishes / turnips.
Voles have no qualms about eating the bait from a sprung trap with a dead compadre a few millimeters away:
They will sometimes eat the walnuts and their dead compadre.
The plastic pedals work much better than the old-style metal pedals at holding the steel arm wire. The wire slides freely on the plastic, in contrast to the previous high-friction metal-on-metal latch.
Some of the traps were entirely too sensitive and required slightly bending the tip of the arm wire upward to increase the friction on the plastic plate. Always always always handle armed traps by the wooden edges beside the kill bar, so when it accidentally snaps your fingers are nowhere near the business end.
After I figured out how to properly bait the traps and we set out half a dozen traps in the most attractive crops, Mary’s garden produced 54 dead voles over the course of 90 days, sometimes in groups of three or four at a time. While this did not prevent all the crop damage, it definitely reduced the problem.
Next year we’ll start early and probably reach triple digits by midsummer.
The same technique with Victor M035 mouse traps (in 12-packs as M035-12) is brutally effective on house mice.
The Smell of Molten Projects in the Morning 