Tag: Rants

And kvetching, too

Software

Canon LiDE 120 Scanner vs. Sane vs. Networking: FAIL

The Canon LiDE 120 scanner on Mary’s desk gets considerable use by both of us, until a recent update of something killed network access to it. The usual searches revealed comments suggesting the sane scanner program has deliberately disabled network access to USB scanners which use the net back end, apparently to prevent loops when one instance shares a networked USB scanner already shared by another instance.

I have no clue how all that works, nor why the change has apparently taken half a dozen years to reach our scanner.

The workaround required downgrading sane on the “server” PC (the one with the Canon scanner) to the most recent version that doesn’t enforce the prohibition:

sudo pacman -U /var/cache/pacman/pkg/sane-1.1.1-2-x86_64.pkg.tar.zst

And preventing further upgrades with a stanza in /etc/pacman.conf:

IgnorePkg = sane

The pamac GUI interface now shows sane as eligible for an upgrade, then reports that it won’t do the deed. That’s survivable.

At some point, not updating the sane package will cause other problems. Perhaps by then we’ll have moved the hulking Epson ET-3830 printer/scanner upstairs and can recycle the Canon scanner.

Oddities

Stonework Pillar: Brace for Impact

Sometimes fake stones fall off on their own accord, but this is impact damage:

Fake Stone Pillar - Impact Damage
Fake Stone Pillar – Impact Damage

Judging from the displaced stones near the top of the picture, that pillar got hit rather firmly by something heavy.

One wonders what the front of the pickup (it’s gotta be a hulking pickup) looked like and how much that repair cost.

I’d bet substantial money on the culprit driving away without offering to pick up the pillar repair bill.

Machine Shop, Science

LED Shoplight Conversion: First Failure

Having started replacing the fluorescent shop lights with LED tubes back in 2016, this was only a matter of time:

Shop Light - failing LEDs
Shop Light – failing LEDs

The next morning the dead section lit up again, albeit with a dim ring at its right end. I think one LED in that string failed open and darkened the whole string, then failed short under the voltage stress, and is now quietly simmering in there with slightly higher than usual current.

The lights over the workbench weren’t in the first wave of conversions, so they may be only four years old.

For sure, they have yet to approach their 50000 hour lifetime …

Oddities, Science

Gas Price Signage: FAIL

The big price displays at the Mobil station on the corner have always behaved oddly, but these replacements began failing within a week of their installation:

Mobil price sign - north face
Mobil price sign – north face

That doesn’t look too bad, until you notice the number of dead LEDs in both red displays.

The south face is in worse shape:

Mobil price sign - south face
Mobil price sign – south face

The green LEDs seem to be failing less rapidly than the reds, but I don’t hold out much hope for them.

The previous display had seven-segment digits made of smooth bars, rather than discrete LEDs. This one appeared after the segments failed at what must have been more than full brightness; the red LEDs were distracting by day and blinding by night.

Maybe they got the LEDs from the same folks selling traffic signals to NYS DOT? The signals around here continue to fail the same way, so I suppose DOT doesn’t replace them until somebody enough people complain.

Oddities

Grand Prize User Interface FAIL

Found in an apartment building lobby:

Apartment lobby call box
Apartment lobby call box

The LCD gibberish comes from an interaction with the camera shutter. It scrolls a lengthy set of instructions, but the peeling labels demonstrate ain’t nobody got time for that.

You were supposed to figure out how to use this thing with no instructions other than the scrolling display. In particular, the multi-multi-function keypad has no labels.

I suspect most folks just haul out their phones and call the tenant.

Electronics Workbench, Home Ec

Flypower Wall Wart: FAIL

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
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
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
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
Flypower LED wart – components

Those caps over there on the left rear don’t look healthy, do they?

Flypower LED wart - failed caps
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.

The identical supply for the identical LED strips on the other side of the kitchen continues to work fine and feel only warm-ish, so I’ll let it be.

Home Ec, Machine Shop

Shoulder PT Pulley: Last 10% Manufacturing

Mary’s PT requires a Shoulder Pulley, so I got one that seemed better constructed than the cheapest Amazon crap. In particular, this view suggested the pulley ran on a bearing:

Slim Panda Shoulder Pulley - detail view
Slim Panda Shoulder Pulley – detail view

Which turned out to be the case, but, also as expected, the whole thing required a bit of finishing before being put in service.

It’s intended to hang from a strap trapped between an interior door and its frame. The strap was intended to attach to the block (a.k.a. “Thickened base”) through a breathtakingly awkward pair of low-end carabiners:

Slim Panda Shoulder Pulley - carabiners
Slim Panda Shoulder Pulley – carabiners

Which I immediately replaced with a simple, silent, sufficiently strong black nylon cable tie:

Shoulder PT Pulley - block hardware
Shoulder PT Pulley – block hardware

Rather than let the metal block clunk against the door, it now sports a pair of cork-surfaced bumper plates:

Shoulder PT Pulley - side plates installed
Shoulder PT Pulley – side plates installed

A doodle of the block dimensions:

Shoulder Pulley - dimension doodle
Shoulder Pulley – dimension doodle

Which turned into a simple LightBurn layout:

Shoulder PT Pulley Side Plates - LB layout
Shoulder PT Pulley Side Plates – LB layout

The blue construction lines represent the actual block & pulley, with the red cut lines offset 2 mm to the outside to ensure the metal stays within the bumpers. It’s possible to pick the block up and whack the pulley against the door, so don’t do that.

Cut out two pieces of 3 mm MDF, two pieces from a cork coaster (covered with blue tape and cut with the paper backing up), peel-n-stick the cork to the MDF, put double-sided foam tape on the block, peel-n-stick the bumpers, then hang on the attic door.

Now it works the way it should!

The LightBurn SVG layout as a GitHub Gist:

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view raw Shoulder PT Pulley Side Plates - LB layout.svg hosted with ❤ by GitHub