Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
The small garage door opener I tote around in the Tour Easy’s underseat bag failed after many years of exposure to the elements, so I paid a few bucks more for a cheap replacement in order to get fast delivery from a (US!) eBay supplier:
Garage door opener remote controls
For whatever it’s worth, before buying the replacement I tried:
Cleaning the battery contacts
Installing a new CR2032 battery
Programming the hitherto-unused buttons to open the door
The remote control would occasionally work, but none of the “repairs” made much difference; I suspect corrosion hidden under the components or cracked solder joints.
The eBay item description clearly, if inarticulately, specifies the compatibility requirement:
key chain remote control
compatible for purple learn button
So I trotted out to the garage and inspected the button:
Sears Garage Door Opener – purple button
Looks purple to me, but, being that type of guy, I also read the adjacent instruction sticker:
Sears Garage Door Opener – instructions
Nobody, nobody, maintains the documentation. [sigh]
I figured if they went to all the trouble of ordering a bazillion switches with purple caps, then the PCB surely holds the corresponding RF filters & firmware & whatever else that button signifies.
Seeing as how we have exactly one garage door opener and no lights or other doodads, I told the opener to obey both the 1 and 2 buttons, thereby dramatically reducing the dexterity required to open the door while pedaling up the driveway. The opener can remember an unspecified number of transmitters, so I didn’t go for all four buttons.
The light switch for our attic turns on a single ceramic socket at the top of the stairs. The bulb burned out a few days ago:
Long-lasting 100 W Incandescent Bulb
To the best of my knowledge, that bulb has been in service since we moved in almost two decades ago. Most likely, it was installed when the house was built in 1955, because it matches several new-old-stock bulbs in a battered box that Came With The House™.
To be fair, the attic light doesn’t see much service, but … it’s been a great cost-performer!
The attic temperatures range from well below 0 °F in the winter to well above 120 °F in the summer, so it’s no place for CFL or LED bulbs. I swapped in a 60 W bulb from my heap, although I doubt it’ll be good for another half-century.
An unfortunate incident put enough water inside our kitchen scale to, ummm, render it inoperative. After a day of drying proved unavailing, I had nothing to lose by disassembling it.
The central label on the back conceals two screws holding the platform to the aluminum beam:
Amazon EK3211 Scale – platform underside
The metal plate twist-locks into the plastic platform. The hot-melt glue holding it in position suggests my construction techniques aren’t all that far off the mark.
The beam cantilevers from a metal structure spreading the load across the plastic base:
Amazon EK3211 Scale – interior overview
These are “after” pictures. Suffice it to say the interior was wet, including water droplets between the LCD panel and its plastic cover. Everything came apart easily, including the LCD with its attached zebra connector, and dried out thoroughly over the next day; I parked the panel atop my monitor for some gentle heating.
After reassembly, it still didn’t work, which turned out to be due to both wires from the battery snapping off at their PCB solder joints. I didn’t think I’d handled it that roughly, but ya never know.
With the wires soldered in place, the scale lit right up again:
Amazon EK3211 Scale – display PCB switches
The display flashed CAL at one point during the proceedings, although the rather thin manual had nothing to say about recalibration and the PCB didn’t have any obvious test points / jumpers / labels to that effect.
Two days of relentless spelunking produced my test weights:
Amazon EK3211 Scale – test weights
Given the provenance of those weights, a 0.2% error might not be the scale’s fault, even if it cost barely 10 bucks.
Anyhow, the original cells crapped out after 2-½ years, when these still delivered 13 days. After 4-½ years, they’re lasting 12 days between charges.
Color me surprised, because they’re 600 mA·h NiMH cells. The originals were 2000 mA·h cells, which you’d expect would last longer, but noooo.
No reason to change them yet, which is good news.
FWIW, I recently bought some cheap brush heads from the usual low-end eBay seller. The OEM brushes have colored bristles which fade to tell you when to change brushes, although I run ’em quite a bit longer than that. The cheap replacements have never-fading colored bristles and, I suspect, all the bristles are much too stiff. The dental hygienist says I’m doing great, so it’s all good.
Sonicare brush heads – cheap vs OEM
High truth: at best, you get what you pay for.
(*) Being that type of guy has some advantages, if you’re that guy. Otherwise, it’s a nasty character flaw.
I had to replace the faucet on a kitchen sink (not our own, for reasons not relevant here) after the steel nuts & washers holding the base to the sink deck rotted completely away. Why faucet manufacturers used plain steel in that location remains a mystery; I’m sure it has something to do with cost reduction and damn the consequences after a few years.
Of course, the new faucet didn’t sit quite flat on the sink deck, due to the raised rim around the perimeter. Installing it like that would prevent the (hard plastic) gasket from sealing against the deck, with the inevitable water leak below the sink; we started this project by scrapping a water-soaked shelf under the sink due to the previous faucet’s wrecked seal. Sliding the oval base forward enough to clear the rim would expose the two holes on each side, with similar results.
You can see the problem if you squint hard enough:
Kitchen Sink Faucet – gasket mask
I decided raising the back of the base by maybe two millimeters wouldn’t be particularly visible, particularly if I filled the space with silicone snot (almost) matching the gasket to provide a solid foundation.
The blue tape masks the sink surface around the gasket to prevent silicone mishaps and simplify cleanup. I held the gasket in place, traced around it with new Xacto knife blade, and peeled the inside out just like I knew what I was doing.
Generous beads of snot around all the holes and across the back will provide a firm base and a good seal:
Kitchen Sink Faucet – gasket in place
With that in place, I aligned the faucet over the gasket, gently tightened the nuts holding the base to the deck, and waited a day for the silicone to start curing before completing the plumbing. It’ll take a while to finish, due to the limited area exposed around the edges.
The water lines now have shutoff ball valves, which the next person to work on it will surely appreciate.
Our ancient Kenmore clothes dryer (Model 110.96282100 for maximal SEO goodness) developed symptoms suggesting the heater and overtemperature cutouts were in fine shape: it continued to turn and heat, but didn’t completely dry the clothes. In addition, it emitted a horrible whine that sounded like a bad bearing.
The wiring diagram pasted on the back panel shows how it works (clicky for more dots):
The motor ran just fine, so Thermal Fuse 2 had never blown at 196 °F.
The Operating Thermostat (along the bottom edge of the diagram) switches the 240 VAC heater off when the clothes temperature (actually, the drum exhaust temperature) exceeds 155 °F. It’s in series with the non-resettable 350 °F thermal cutoff and the resettable 250 °F high limit thermostat, both of which were intact, as shown by the fact that the heater still worked.
We generally run the dryer in Auto mode, with the Temperature Selector in the middle position. The Selector varies the resistance in series with the Operating Thermostat heater (near the middle of the diagram), controlled by Timer Switch 1: increasing resistance reduces the heater current and requires hotter clothes before the Thermostat trips. For the first part of the cycle, the BK-BU contact closes to allow the Selector to affect the current. The BK-V contact also closes during the last part of the cycle, cutting out the Selector and letting the Thermostat hold the clothes at 155 °F by cycling the drum heater.
So I installed a new Operating Thermostat (plus the accompanying thermal fuse I didn’t need):
Kenmore clothes dryer – operating thermostat
You can do that from the back of the dryer without dismantling it, by removing the rear cover.
For whatever it’s worth, the replacement Operating Thermostat heater has a 74 kΩ resistance, not the 5.6 to 8.4 kΩ range shown on the wiring diagram. Preliminary testing suggests it does what it’s supposed to, so maybe they’ve improved (and, surely, cheapnified) its guts to work with 1% of the original power. More likely, the Temperature Selector now doesn’t do anything, as its (minimum) 10 kΩ resistance on the High setting doesn’t amount to squat compared with the new thermostat heater, but we don’t have enough experience to say anything definite.
In an attempt to fix the whine, I took the whole thing apart to replace the idler wheels supporting the drum, the drum drive belt, and the belt tensioner pulley. The interior of the dryer is filled with sharp edges and hatred, so expect some bloodshed.
Removing and installing the triangular wheel retainers requires a small flat-blade screwdriver and considerable muttering. Here’s the old wheel to the left of the motor, before replacement:
Kenmore clothes dryer – tub support wheel
After reassembling the dryer, the heater worked fine.
The whine also worked fine, much to my dismay.
So I took it all apart again, removed the plate covering the duct from the drum exhaust port to the blower wheel on the motor, removed a generous handful of lint from the middle of the blower wheel, extracted a pile of debris from the bottom of the duct below the wheel, vacuumed everything in sight, reassembled the dryer, and it now sounds great.
Along the way, a small square brass (?) rod fell out of the debris, sporting one shiny end, well-worn to a diagonal slope. I think the rod got trapped between the duct and the back of the blower wheel, where it would produce the whine only when the motor got up to speed (thus, sounding OK while hand-turning the motor). The accumulated debris & lint held it in place, so flipping the dryer on its face and rotating the motor in both directions had no effect: turning the dryer upright simply let it fall back into the same position.
No pictures, alas. We did the second teardown in a white-hot frenzy to Get It Done and swept the brass rod away with all the other debris.
The Smell of Molten Projects in the Morning 