Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
The time has come to add a Bafang mid-drive motor to my Tour Easy recumbent, much like the one Mary has been using for the last two years. When I got to the point of installing the motor in the bottom bracket shell, this happened:
Bafang Triangle Plate – jammed screw
It turns out the triangle plate has slightly misplaced bolt holes:
Bafang Triangle Plate – misplaced bolt holes
If you look very carefully, you’ll see the holes sit just slightly above the midline of those ears. The additional fractional millimeter below the holes touches the motor end bell and prevents them from lining up with the tapped holes.
Normally, you’d just hit the plate with a file and be done with it, but it’s ferociously hardened steel: a file bounces right off.
I deployed a Dremel sanding drum above the ShopVac’s snout to catch the abrasive dust, eroded just enough steel to line up the holes, and everything now fits the way it should.
The shower faucet handles have been getting looser, but once a decade seems reasonable. This time around, however, the setscrews had dug themselves so far into the splined plastic fittings that they had run out of thread:
American Standard Shower Handle rebuild – gouged setscrew sockets
Wipe out the crud, clean out what’s left with alcohol to encourage stick-to-it-ivity, and fill the cavities with JB Kwikweld epoxy:
American Standard Shower Handle rebuild – epoxy fill
When it cures, file a flat across the sockets:
American Standard Shower Handle rebuild – flatted
Reinstall in reverse order with a dot of NeverSeez on the setscrews for good measure.
The IR sensor on the under-cabinet LED lights I installed half a dozen years ago became increasingly flaky. Its wall wart power supply was on the hot side of uncomfortably warm, so I had an obvious culprit.
The data plate says it’s UL Listed, which is comforting:
Flypower LED wart – data plate
The open-circuit output of a 12 VDC power supply should not look like this:
FlyPower 12V 1A – no load
The horizontal scale is 100 ms/div, so those ramps seem much more languid than you might expect from a 60 Hz wall wart.
Adding a 16 Ω load to draw maybe 750 mA got its attention:
FlyPower 12V 1A – 16ohm load
The average may be 12 V with too-large dips at the expected 120 Hz, but looky at all the hash riding the output!
No wonder the IR sensor was having such a hard time. When the LEDs are off the voltage ramps between 16 and 5 V. When it eventually turns on the supply has impossible noise levels.
So I cracked the case and extracted the electronics:
Flypower LED wart – components
Those caps over there on the left rear don’t look healthy, do they?
Flypower LED wart – failed caps
No. No, they don’t and you shouldn’t be able to see the wiring inside the inductor between them, either.
Probing the Box o’ Wall Warts produced a similar-ish wart that only required harvesting and splicing the teeny coax plug from the failed adapter to put the LED strips back into normal operation.
Being that type of guy, I wanted to salvage a loooong square-head bolt from the utility pole stub formerly holding up the mailboxes, which would require a few gazillion turns of its square head with the Adjustable Elephant Wrench. After verifying I couldn’t just hammer the mumble thing through the pole, I gave a few turns of the Universal Socket on a ratchet:
Universal Socket Wrench
It’s intended for goobered hex heads up to 1-¼ inch, but the pins slide down around pretty much anything that sticks out and jam against the shell, so it’s handy for those last-ditch extraction events.
After verifying doing this by hand would occupy me until just before the heat death of the universe, I followed Mad Phil’s signal connector adage: “If you can get to BNC, you can get to anything.”
Some rummaging produced this unsteady mechanical ziggurat:
Universal Socket to quarter-inch hex – adapter stack
From bottom to top:
Universal Socket with ½ inch square drive socket
1/2 inch square drive to ¾ inch hex
19 mm (close enough to ¾ inch) 12-point socket to ⅜ inch square drive socket
⅜ inch square drive to ¼ inch square drive socket
¼ inch square drive to ¼ inch hex drive
Then stick the teeny end into the hand drill, rig engines for reverse running, and whine away on that bolt, which obligingly backed right out.
After the fact, I found the obviously missing ¼ to ½ inch square drive adapter hiding in the Drawer o’ Sockets:
Universal Socket – short adapter stack
Which doesn’t make any more sense, but is less likely to fall apart under normal use.
Aaaaand one more adapter makes this possible:
Improper square drive adapter stack
That’s a 50 mm socket turned by ¼ inch hex drive in four easy steps, although I’m reasonably sure it still won’t get the idler bogies off my armored personnel carrier.
The stray adapter steps down from ½ square to ⅜ square, should a need for a breaker bar occur during eyeball surgery.
A power failure apparently pushed the ancient RCA alarm clock over the edge into a mode where it ignored its pushbuttons and displayed a time based on a hitherto unknown exoplanet. Popping the case revealed it’s been simmering in its own juices for quite a while:
RCA Alarm Clock – PCB overheat
There’s nothing obviously scorched on the underside of the PCB, although a large SMD resistor might be the source of the problem.
Having been around this block a few times, I unsoldered that big electrolytic cap with its guts protruding from the overwrap:
RCA Alarm Clock – failed cap value
Nope, that’s not really an electrolytic cap any more.
Lacking a 2200 µF cap of suitable voltage rating, but knowing cap tolerances allow for considerable windage, this worked out well enough:
RCA Alarm Clock – replacement caps
Two smaller caps measuring on the low side of OK now reside in the e-waste box.
The white diffuser over the last digit improves it in ways I do not profess to understand, but am pleased to implement:
RCA Alarm Clock – in place
It’s held in place by two strips of LSE tape to see how it reacts to prolonged shear force, no matter how gentle.
Combining a new mailbox with a post and an old mailbox I had on hand, upcycling some scrap wood, then sticking on a few digits and a seasonal decoration found on a walk, should shake loose the mail currently stuck in the USPS delivery system:
Mailboxes – south view
That’s an Extra Large mailbox, suitable for most packages arriving by USPS, and dwarfing the ordinary mailbox on the north side:
The boxes sit on slabs harvested from an old door and screwed to two layers of Chinese plywood from the laser cutter’s shipping crate, all unpainted / untreated interior-grade (at best) wood cut with a circular saw. My assumption is they’ll last long enough for the purpose and, not having formed a deep emotional bond with them, I won’t feel too bad when the assembly gets pulverized.
The whole affair sports a rakish tilt toward the street, in the hope of encouraging rainwater to run off, rather than soak in, but I fully expect the untreated plywood to act as a sponge and delaminate / curl / splay in a spectacular & amusing fashion.
The pale rectangle across the vertical post is a (laser cut!) Chinese plywood plate intended to hold the crossbar together. The vertical and horizontal posts meet in a simple cross lap joint that surely wasn’t intended to support nearly so much weight: reinforcement seems appropriate.
The Smell of Molten Projects in the Morning 