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
Crawling around on the floor under the oven reminded me of the bottom pan we salvaged from the hulking oven that Came With The House™:
A closer look:
I can’t vouch for their accuracy, but finding recommended baking temperatures and times printed exactly where they will come in handy seems like a great idea.
It’s another example of the rule Eks taught me: When you must look up something, write it where you will need it the next time.
Things remained rather quiet at the end of the driveway for a few months, then this happened just before breakfast:
Rt 376 had accumulated some sleet overnight and freezing rain was still falling. The driver apparently lost control around the curve, missed the fire hydrant behind me, and went up the embankment sideways at a pretty good clip.
As far as I can make out, the left front door took out the mailbox post, which was the stump of a utility pole installed long before we bought the property:
Admittedly, the post was rotten around its base, but remained a substantial chunk of wood. The black plastic curl is the air deflector formerly sealing the front of the car’s undercarriage.
Seen from the far end of the debris field, the car smashed dead center into the mighty honeysuckle bush, shed a variety of small parts, recoiled backwards, and tagged the tree as it rolled down the embankment:
The mailboxes sit on the shoulder to the right of the car.
No serious injuries to the driver or passengers, although they got an ambulance ride to the ER to make sure.
Those dents just ain’t gonna buff out:
I did get three years out of the repaired mailbox hinges and perhaps I should preemptively transfer the hardware to the new mailbox.
There’s never a dull moment around here.
Mary handed me a bobbin with a trouble report: it fit into the bobbin holder either way, but would go into the sewing machine either poorly or not at all.
Based on past experience with this lot of bobbins (*), I expected to find a burr inside the steel hub left behind by the saw cut creating the drive dog slot, so this came as a surprise:
A closer look:
That pebble was jammed in place so firmly I needed a pin punch: a small screwdriver wasn’t enough.
It came new from the factory like that, which makes one wonder just exactly what the factory floor looks like.
More likely, the bobbins spend their last few hours in a vibratory polisher and that little rock just crept with all the walnut shell kibble.
Works fine now, so we’ll call it a win.
(*) I gave her a lot of 100 to ensure she never had to unload a bobbin to keep her new Juki well-fed.
A screws in one of Mary’s eyeglasses unscrewed itself, but, miraculously, we found it and I retired to the shop.
Because the glasses have spring temples, the screw would not align no matter what force I applied to it:
So I just embiggened the hole until the available force did the trick:
Dots of Loctite worked into the threads should prevent that from happening again, but I’ve learned to never say never.
In retrospect, the temple pivots have an exposed slot that I think would allow jamming a block in place after pulling the spring-loaded pivot outward. Temple springs are impossibly stiff and I have previously failed to budge them in glasses without the slots, so I don’t know how well that might work.
Verily: If brute force isn’t working for you, then you’re not using enough of it.
During the course of diagnosing and fixing the latest oven igniter failure, an unrelated series of events produced a flood under the kitchen sink and across the floor. After cleaning up the mess and determining the floor under the cabinet was merely damp, rather than wet, I drilled a hole suitable for another PC cooling fan from the Box o’ MostlyFans, installed the fan to pull air upward, and let it run for a couple of days while watching the humidity drop.
Fortunately, I had a hole saw exactly the right size for an 80 mm case fan:
I will lay big money on a bet saying your kitchen cabinets don’t have Real Wood like that, nor are the interiors painted bold Chinese Red. This place really is a time capsule from 1955.
While the drying happened, I made a hole cover from 1.5 mm black acrylic and, there being no style points involved, rounded up a quartet of black-oxide self-drilling sheet metal screws to hold it in place.
Although it’s not obvious, there’s a layer of transparent plastic “shelf paper” in there. It covers the fan hole under the cover, so any future spills will have approximately the same difficulty reaching the floor as this one did.
The LightBurn layout produces both the fan cover and a template to mark the four screw holes around the fan opening:
The blue tool layer lines serve as a guide for the rest of the cover layout; the matching orange square on the right marks the fan outline on the drill template as a quick size check.
No need for an SVG version, because now that you have the general idea, it’s easy to recreate it for your own fan.
Our story so far:
Apparently igniters last about eight years, regardless of provenance, because the igniter just failed, with the usual symptoms of low current draw (about 2 A), failed ignition, and a faint smell of propane (well, mercaptan) before the safety valve kicked in:
The new igniter, another low-buck Amazon offering, came with half a green plastic connector block that mated neatly with the existing half under the oven. Unfortunately, the new wires had female pins crimped on their ends, rather than the male pins required by the existing connector and the ceramic wire nuts I’d used to join the previous igniter to the OEM connector were non-removable.
So I trimmed the old wires to a usable length and applied the new ceramic wire nuts to the stubs:
Also as before, the new igniter measures 3 A, definitely below the low end of the valve’s 3.3 to 3.6 A range:
If this one lasts eight years, I won’t be the guy replacing it …
Other than demonstrating that it’s possible to laser-engrave a 3 mm deep pocket in a ¼ inch thick piece of scrap paneling, the process didn’t have much to recommend it:
So I re-did the layout to put the 3 mm mirror in 3 mm thick plywood:
The coaster has a self-adhesive cork pad on the bottom, which required an intermediate adhesive layer holding the aluminized Mylar reflector on the bottom of the mirror to brighten the colored areas.
The LightBurn layout shows all the pieces:
The plywood cuts with the good side down, although “good” is certainly a judgement call with B/BB grade plywood. I cover the good side with blue painter’s tape to reduce scorch marks. In a real application, you’d do some sanding and finishing, probably before cutting; in this case, I want to see what happens to bare wood in coaster duty.
Engrave and cut the mirror with the backing upward:
The tracer rounds may be burning aluminum.
I colored the engraved areas with fat-tip permanent markers, despite knowing the alcohol will crack the acrylic. In real life, you’d use spray paint, probably with laser-cut tape masks.
The adhesive layer extends 2 mm beyond the mirror perimeter to stick onto the bottom face of the plywood:
Peeling off the paper reveals the adhesive tape stuck to the back side of the mirror:
Apply the similarly embiggened aluminized Mylar to the adhesive:
Cutting the holly shape directly from the original foot-square adhesive sheet lets me tuck smaller shapes into the remaining uncut areas. In a production environment, however, joining the Mylar and adhesive (perhaps using pre-cut squares), then cutting them as one sheet would definitely simplify the process.
Then peel-n-stick a cork disk (thus explaining why the plywood is exactly 4 inch OD) on the bottom:
I’ve been aligning the cork by feel, which explains the half-millimeter overhang along the right side. Inexplicably, I have yet to justify an alignment fixture.
The LightBurn SVG layout as a GitHub Gist:
The Smell of Molten Projects in the Morning 
