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.
If it used to work, it can work again
The blade on one of the Jonas vegetable peelers cracked, which suggests it’s the counterfeit version:
I grooved the metal pin running through the handle:
A brass tube from the Little Tray o’ Cutoffs and some epoxy should hold things together forevermore:
The rainbow colors come from an instantly aborted attempt to silver-solder the parts together. The fact that I even tried a stunt like that shows I’m definitely not the brightest bulb in the chandelier these days.
For completeness, all of the surviving UPS sealed lead-acid batteries compared with a new battery:
They’re all discharged at 4 A, far higher than the nominal “20 hour” rate of 450 mA = 9 A·hr / 20 hr, but an order of magnitude closer to the rated UPS output of a few hundred watts which would call for a few tens of amps.
The new battery delivers 73 W·hr under those conditions, perhaps 50% more than the 50-ish W·hr from the used batteries, and with a much higher overall terminal voltage during the discharge.
Nothing unexpected, but now we know …
Having recently emptied the OXO pepper grinder we (mistakenly?) bought as a salt mill, I took it apart for a deep rinsing and cleanup:
It turns out the somewhat corroded square shaft is aluminum, neither the cheap steel I expected nor the stainless steel it should be. Perhaps OXO cost-reduced the shaft, discovered aluminum is a poor choice in a saline environment, and changed the packaging to compensate?
Removing / installing the Jesus clip requires careful whacking with a hollow-tip punch against the shaft, with the whole affair laid flat on shop towels, the handle held down to prevent rotation, and the wrap-around body capturing the escaping clip.
Shaft corrosion as of Summer 2020:
Soaking the body in hot water got rid of salt crusts and filled the shell with water. There being no way to completely dry the thing, I parked it in the sun for a day, refilled it, and was unsurprised when the (dried) salt turned into an assortment of moist crystals.
We obviously need a real salt mill …
Having just replaced Rev 1 of the amber running light with Rev 3 (about which, more later) on Mary’s Tour Easy, both the front and rear lights began blinking erratically. Given that they have completely independent circuitry, this strongly suggests a power problem.
Herewith, the headlight circuit voltage:
The voltage should be a constant 6 or 6.3 V, depending on which description you most recently read. That is the case with only one light attached, so the problem occurs only when running both lights.
The four pulses come from the amber LED’s Morse code “b” (dah-dit-dit-dit) with a 85 ms dits; the first dah pulse should be three times longer than the dits and definitely isn’t. The rear light’s red LED stays on continuously, except for two dark dits, so it draws a constant current and does not produce any changes in this trace.
Both lights have 2.0 Ω sense resistors setting the LED current to 400 mA, which corresponds to 250 mA each from the Bafang controller’s 6.3 V headlight circuit. The headlight circuit’s total of 500 mA should work fine, although the “spec” seems to be basically whatever the OEM headlight requires.
The Rev 1 amber light ran the LED at 360 mA with a supply current around 450 mA. That light and the rear light on the back ran fine, so the supply seems to have a hard maximum current limit at (a bit less than?) 500 mA.
The least-awful solution seems to be backing off both LED currents to 360 mA to keep the total supply current well under 500 mA.
The UPS coddling the M2 printer began complaining about a bad battery, so I ran (nearly) all the UPS batteries through the tester:
The two blue flubs in the lower left come from the failed battery, with the dotted trace after charging to 13.7 V and letting the current drop to 20 mA.
The red and green traces come from two other UPS batteries installed in 2016, with the dotted traces after charging similarly. The orange-ish trace is from the battery in a Cyberpower UPS bought in 2016, so it looks like all batteries of that vintage fade equally.
Except for another pair of batteries in another UPS that had discharged stone cold dead; it may have been shut down and unplugged during a power outage and they never quite recovered.
After five years, it’s time to refresh the fleet …
The Bondhus Lifetime Guarantee works, as a replacement wrench just arrived:
A close look at the aligned tips suggests the defective wrench blank was mis-chucked in the machine cutting the ball end:
All’s well that ends well: thank you, Bondhus!
The lesser kitchen faucet began dribbling and required replacement, as there are no user serviceable parts within. One of the 3D printed adapters I built during the previous iteration had disintegrated:
The new faucet came with a somewhat different baseplate and I managed to conjure a firm, sealed mount from the various parts without further construction.
The nicely curved brass snout is the third in my collection. Surely they’ll come in handy for something!
While I was in a plumbing state of mind, I again replaced the spout O-rings in the never-sufficiently-to-be-damned American Standard Elite (hah!) faucet, as it was also dribbling.
This time, I used oxalic acid to remove the assorted scale and crud inside the spout. It seemed to be more effective than the usual white vinegar, although nothing seems to preserve the O-rings.
The Smell of Molten Projects in the Morning 