Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
Each air conditioning unit has a pair of lightning rods atop it, with their aluminum grounding cables securely clamped to the steel frame underneath.
The rod reclining on its side caught my eye. Perhaps its fat cable wasn’t relaxed enough during installation, although I thought those wide bases would be firmly screwed to the unit’s steel top. Of course, that could be the only one without screws.
The building extends another three stories upward from that roof, but our experience suggests lightning strikes where it will.
The bathroom ceiling fixture has a nightlight position that we use occasionally, but eventually the little 7 W Christmas Tree bulb failed and I installed this hulk from a box of CFL bulbs a friend scrapped out after switching to LED bulbs:
MaxLite CFL – overview
I never tested whether it actually drew 3 W, but, hey I could feel good. Right? Right?
Anyhow, this one failed after a few years, too. The “bulb” envelope looked like it might make an attractive blinkie or glowie, so I decided to harvest it.
The candelabra screw base felt loose and popped off with a push:
MaxLite CFL – overflow cap
Perhaps they chose the envelope before finalizing the circuitry?
This is why you need a lathe in your shop:
MaxLite CFL – lathe cutting
It wasn’t particularly well centered, so that was done dead slow and finished with a few hand turns of the chuck. Obviously, I need a crank for the spindle.
The rest of the circuitry is pretty well packed under that tall cap:
MaxLite CFL – circuitry
Pulling the PCB out revealed the tube wiring:
MaxLite CFL – tube wires
Cut the wires and chuck it up again:
MaxLite CFL – envelope turning setup
Turn dead slow again until it breaks through:
MaxLite CFL – envelope breakthrough
Then finish by hand:
MaxLite CFL – tube and envelope
It’s too cute to throw out, but … sheesh you can see why recycling this stuff is so difficult.
For whatever it’s worth, I replaced it with a 3 W LED candelabra bulb that is way too bright.
The trail camera uses two parallel banks of four series AA cells to get enough oomph for its IR floodlight. I’m not convinced using bucked lithium AA cells in that configuration is a Good Idea, but it’s worth investigating.
These are labeled HW, rather than Fuvaly, because it seems one cannot swim twice in the same river:
HW bucked Li AA cells
In any event, they come close to their claimed 2.8 W·hr capacity:
HW bucked Li AA – 2023-05
The lower pair of traces (red & black) are single cells at 2.7-ish W·hr, the blue trace is a pair at 5.4 W·hr, and the green trace is a quartet at 9.8 W·hr. Surprisingly close, given some previous results in this field.
Recharging the cells after those tests shows they all take 3 hours ± a few minutes to soak up 730 mA·hr ± a few mA·hr, so they’re decently matched.
Measuring the terminal voltage with a 10 mA load after that charge lets me match a pair of quartets to 1 mV, which is obviously absurd:
HW bucked Li cells – initial charge 2023-05-05
The numbers in the upper left corner show the initial charge of four cells at a time required the same time within a minute and the same energy within 4%.
Sticking them in the trail camera must await using up the current set of alkaline AA cells.
Bonus: a lithium fire in a trail camera won’t burn down the house.
After all, pictures like this are definitely worth the hassle:
I read these reassuring instructions in the elevator of a different building:
Elevator power failure instructions
I’d be mildly unsurprised to discover the elevator controls also handle the interior lighting, invariably putting me in the dark while the thing reboots. At least the paper would remain readable, because phones can become flashlights under duress.
Our Young Engineer knits during rare moments of downtime and sketched an idea for stitch counters to mark progress between those moments. There being nothing like a new project to take one’s mind off all of one’s previous projects:
Stitch Counters – overview
These are more along the lines of feasibility / material tests than finished products, so you’ll see plenty of rough edges.
Prior to doing this, we agreed that 3 mm material was probably too thick, particularly given the small scale: the hexagons are 10 mm edge-to-edge with a 1.5 mm hole for the jump ring.
The jump rings are (mostly) 8 mm OD, which may or may not be the right diameter for all possible knitting needles.
The count sequence goes 10 20 10 40 50 10 with alternating colors:
Stitch Counters – red and blue
Those came from 3 mm red and blue transparent acrylic, looking entirely too much like candy. Cutting two identical layouts from two different materials, then swapping a few counters, gives me two related-but-different sets. This idea is also subject to revision.
I like the set of 3 mm acrylic mirror counters colored with Sharpie:
Stitch Counters – mirror
Alas, the unprotected mirror backing won’t survive long in the real world and Sharpie ink tends to stress-crack the acrylic. Bonding a thin colored sheet / gel filter to the back with an adhesive sheet in between would work, although I don’t look forward to the fiddly alignment. Bonus: sticky edges are a nonstarter in this application.
A setup error produced a set of unmarked counters that might still come in handy for something:
PXL_20230507_150124595 – Stitch Counters – blue blank
Trolase acrylic 1/16 inch = 1.5 mm sheets produce the most visible legends, in a relentlessly industrial sort of way:
Stitch Counters – Trolase
Those have a single thin layer atop a white or black base sheet, but three-layer 1.5 mm Trolase sheets with matching top and bottom colors (cladding on a white core) would look better.
If you can’t decide on a color, go clear:
Stitch Counters – clear
All of those appear on a background of some thin DIY plywood:
Stitch Counters – veneer plywood sheets
The bottom sheet is very pale veneer that came with a layer of genuine 3M 468 transfer tape with 200MP adhesive. I stuck three different veneers on three 100×50 mm rectangles of the stuff to make 1.5 mm thick “plywood”. The adhesive sheet provides lateral strength, not the wood fibers, so it’s not quite as easy to tear as the broken fragment would suggest.
The results look passable, although there’s room for improvement:
Stitch Counters – veneer plywood
After engraving & cutting, I slathered them with clear polyurethane finish and hung them up to dry:
Stitch Counters – wood finish curing
I like the effect, but using the pale veneer for the bottom layer made them look identical from that side. Worse, two of the three top layer veneers had nearly identical colors (one has more grain) after the finish cured.
More thought seems in order, but at least I’ve explored some of the solution space.
The knuckle joint on the Dirt Devil stick vacuum failed, so it followed us home instead of leaping into the trash:
Dirt Devil – broken swivel joint
Although the fitting seems to be made of ABS, it’s now missing major chunks of plastic in the high-stress areas, so rebuilding it seems not worth the effort.
Because we don’t have any carpets and this one will never leave the basement, I extracted the carpet beater brush and its motor, only to find Yet Another Example of poor assembly practices:
Dirt Devil – stray strands
It’s a 12 V (-ish, I didn’t measure whatever comes out of the vacuum head) DC motor and those errant strands aren’t quite long enough to meet in the middle. The yellow rectangle is a thermal fuse that would be shorted out if the strands were a bit longer.
The broken joint lets the head swivel from side to side, but the elevation joint is still good. If I don’t expect too much, the thing might still suffice for extracting dust from under the benches:
Dirt Devil – taped joint
Worst case, I can swap in a classic floor brush using one of the adapters I made a while ago:
Dirt Devil adapters – assembled
That was easy, if only because I skipped the hard part …
It’s more properly called a “chain guide” and is basically a shifter cage minus the mechanism:
Chain Catcher – side view
Because the Tour Easy frame has a 25 mm tube where the guide’s clamp expects a minimum 31.8 mm tube, a 3D printed adapter fills the gap:
Chain Catcher adapter ring – solid model
The hole is off-center because it seemed like a good idea, although it’s not strictly necessary. The flange helps align the pieces while tightening the clamp screw.
The guide cage clears the chain on all sides while up on the work stand, but there’s nothing like getting out on the road to find out why something doesn’t work as you expect.
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The Smell of Molten Projects in the Morning 