Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
An odd smell in the Basement Laboratory Chemical Warehouse led to this discovery:
Leaking aerosol can
It’s a can of spray-on topical anesthetic That Came With The House™, so it’s almost certainly four decades old and, other than being moved to that shelf, hasn’t been touched in the last quarter century.
Surprisingly, the orange-brown goo wiped off the shelf almost completely. The similarly old box of stain remover on the left was a dead loss.
‘Tis the season of leaf shredding and yard cleanup, with a generous helping of home chores and maintenance on the side, so I’ll be posting intermittently for a while.
Just before midnight, the garage door opened, but, being early-to-bed folks, it wasn’t either of us. I pulled my fingernails out of the ceiling, padded out to the garage, verified there was nobody (not even a critter more substantial than a spider) inside, closed the door with the hardwired control button on the wall, and went back to bed. An hour later, the door opened again, then tried to take a bite out of me when I walked under it.
I pulled the opener’s plug, yanked its emergency release latch, lowered the door, and returned to bed; it was not a restful night.
The key to the diagnosis came from the little yellow LED on the back of the opener, just above the purple LEARN button:
Craftsman Garage Opener – indicator LED
In addition to indicating various programming states, it also lights when the opener’s radio receives a transmission from one of the remote controls. The LED was flickering continuously, showing that something was hosing the receiver with RF.
We have three remotes: one in the car, one on my bike, and one in the back room overlooking the garage. None of them worked reliably, suggesting the RF interference was clobbering their transmissions.
Disabling the remotes by removing their batteries (which were all good) also stopped the interference. Reinstalling the batteries one-by-one identified the rogue opener:
Craftsman Garage Opener – remote innards
The slip of paper let me isolate the battery terminal and stick a milliammeter in the circuit, which showed the remote was drawing about 1.5 mA continuously. I thought one of the pushbutton switches had gone flaky, but swapping an unused one for the main door switch had no effect.
I lost track of which remote it was, but it lived in the car or the back room for all its life, so it hasn’t suffered extreme environmental stress. I have no idea why it would fail late one night, although I admit to not monitoring the LED on a regular basis. For whatever it’s worth, in the weeks leading up to the failure, activating the opener sometimes required two pokes at the remote, but nothing bad enough to prompt any further investigation.
A new cheap knockoff remote arrived in few days and it’s all good.
Protip: different openers, even from the same company, use different RF frequencies. For Craftsman openers, the color of the LEARN button is the key to the frequency; purple = 139.53753 MHz.
Zenni ships their glasses in a snap-close case with a fuzzy insert on the bottom, but after you unpack the cleaning cloth and suchlike, the glasses rattle against the hard plastic top.
Make trial fit prototype from thin cardboard and trace it onto a sheet of craft foam:
Eyeglass case foam padding – outline
The pen, much favored by quiltists, has a white ceramic lead that washes out of dark fabrics. You can find a corresponding dark-lead pen, but I can use an ordinary pencil.
Use different colors for different glasses:
Eyeglass case foam padding – installed
Then walk ninja-style again.
Protip: slip an address label atop the foam so a nice person can reunite you with your glasses, should they slip out of your pocket in the unlikely event you sit down anywhere other than in your house.
Start by removing the tiny screw and the nose pad:
Zenni glasses nosepad – socket
Apply a metal bending pliers (with the concave jaw around bottom of the socket), twist until it lines up properly, then reinstall the pad:
Zenni glasses nosepad – aligned
No big deal if you happen to have the pliers. Bonus: apply Parafilm to prevent scratching the lenses, OK?
For what it’s worth, the latest set of four spectacles with high-index (not polycarbonate) progressive lenses in metal frames cost a bit over $200 delivered. The last time around, two specs cost a bit more than half that.
On the other paw, I’ve been repairing Mary’s collection of full-frontal retailglasses for quite a while, because she’s frustrated with making multiple trips to have The Nice Man repeatedly apply final tweakage.