Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
The replacement probe has a woven metal jacket that’s allegedly more rugged than the original plastic, but I think the main difference comes from the additional strain relief at the end of the probe:
Kitchen thermometer – new probe
That still looks abrupt to me, so I wrapped a silicone tape snippet around the joint:
Kitchen thermometer – new strain relief
Probably not food-safe, definitely butt-ugly, but I don’t want to replace the probe again for a long time.
FWIW, although the probe description says it’s compatible with Taylor 1970N thermometers and doesn’t mention the 1478 we have, the 2.5 mm plug fits (no suprise there) and the display shows appropriate temperatures; it seems no less accurate than the original probe.
We’ve been doing a lot of roasting and bought a not-dirt-cheap Taylor 1478 digital kitchen thermometer with a long probe wire to monitor the meat temperature. As soon as I unpacked it, I knew this would eventually happen:
Kitchen thermometer – nicked probe wire
The cable lasted just long enough to ensure the thermometer warranty expired; it’s a deliberate design flaw if I’ve ever seen one.
The thermistor inside the probe seems to be 100 kΩ at ordinary temperatures, although I’d be completely unsurprised to find that Taylor uses a slightly nonstandard resistance. Because nonstandard, of course.
Anyhow, replacement probes (*) are readily available from the usual Amazon suppliers, feature stainless steel braid sheathing and cost about as much as a whole new thermometer (albeit those still have cheap plastic insulation). With a replacement on order, I hauled the failed probe to the shop for an autopsy and possible resurrection…
Although I hoped that hammering out the crimp would release the thermistor, it was not to be. In retrospect, pulling on the probe wire probably killed it, but I didn’t know that at the time.
A spring intended to stabilize tubing while bending worked just fine to un-bend the probe:
Kitchen thermometer – unbending
But, alas, the thermistor still didn’t emerge from the more-or-less straightened probe.
Some deft work with a Dremel cutoff wheel sliced enough off the stainless steel tube that I could splice the wires:
Kitchen thermometer – probe cutting
More cutoff wheel work smoothed the edges of that raw cut end, although the result wasn’t anything to show off.
The spliced and insulated probe definitely don’t win any awards, either:
Kitchen thermometer – probe rebuild
I doubt that the heatshrink tubing or silicone wrap underneath it would be suitable for roasts in the kitchen, but that’s moot: the probe remained intermittent.
If the new probe is also intermittent, then I’ll suspect the crappy 2.5 mm jack in the side of the thermometer…
(*) It’s not clear that a replacement probe for a 1470N thermometer will work with a 1478 thermometer. I’m gambling that Taylor wouldn’t be so stupidannoying deliberately obtuse as to use different probe thermistors, but that’s surely a bad bet. There’s no reason to believe Taylor actually makes any of this stuff, which means different models may come from entirely different designers / factories with entirely different supply chains.
While looking for something else, I found the old Trust Multimedia Mouse and discovered its nice grippy rubber surfaces had become adhesive slime. Graduated efforts with water, rubbing alcohol, and denatured alcohol being unavailing, I finally hit it with xylene and that did the trick:
Degummed Trust Mouse
Of course, xylene also wiped away the fancy button markings and irretrievably scarred the surface, but at least I can pick the mouse up without having it stick to my hand. Not that I pick it up that often, obviously.
Several other gadgets have a similar grippy finish, so now I know what to do when it turns gummy: throw the gadgets out…
Another of Mary’s glasses snapped at the temple joint:
Broken eyeglass temple spring
This one has a spring inside the joint that latches the temple on either side of that square inner corner. Obviously, there’s no way to reconnect the broken stub with the spring retracted inside the brazed temple box, so:
File off the corner
Fill the socket with epoxy
Ease the stub in place
Wipe off the excess epoxy
Align on the workbench
Let it cure overnight
At least the hinge folds again, even if the spring doesn’t work:
Broken eyeglass temple spring – epoxied
She promises to scrap out her oldest glasses after the next eye exam…
A friend reported that three of the four heating blankets he’s bought over the last several years have failed, so he sent the lot to me for teardown and maybe repair.
Looking inside one controller showed some obviously bad solder joints:
Blanket controller – bad joints
Hitting the joints with the soldering iron improved their outlook on life, but the controller remained dead; they weren’t really bad joints, they just looked that way.
If the “lot number” labels on the controllers mean anything, they’ve tried three different triac mounts over the years:
A through-hole triac screwed to the board with no heatsink
An SMD triac using the PCB copper as a heatsink
A through-hole triac with a big aluminum heatsink
That’s in order of ascending lot number, suggesting the triac caused some reliability problems.
I’m still trying to figure out how to probe the circuitry without killing myself. An isolation transformer comes to mind, because the blanket dissipates only 85 W.
I’m not sure how many folks will drop 1.1 large in response to that mailing, but surely it doesn’t take very many to break even. Whew!
If I’m parsing the New York Times signup page correctly, an annual daily subscription delivered here in the hinterlands will set you back a mere $691, direct from the Official Source.
The rules for disposing of latex paint around here require that it be “dried with sawdust”, whatever that means. Over the years we’ve accumulated quite a lot of latex paint, in addition to a rich stockpile that Came With The House™, and I simply don’t have that much sawdust.
Since they don’t seem to object to dried latex paint, I made a drying tub by stapling aluminum flashing around a stand that used to hold a water heater off the basement floor, lined it with heavy plastic, and started pouring latex paint into it:
Paint drying tub
After a year of intermittently dumping paint, that solid latex cookie must be two inches thick and I suppose it’s time to toss the first batch.
For what it’s worth, I discovered that storing paint cans upside down doesn’t guarantee that the paint remains fresh. This can had a solid latex cookie against the lid, with plenty of corrosion to go around:
Paint can stored upside-down – interior
The coagulated paint above the latex cookie was as horrible as you might expect.
The Smell of Molten Projects in the Morning 