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.

Category: Home Ec

Things around the home & hearth

Monthly Science: Basement Humidity Step Changes

Can you tell when our dehumidifier failed?

Basement Temp Humidity – 2015-05 to 2015-07

The step change in Week 22 shows when the replacement took over. After some poking around, Amazon Prime FTW.

The square-ish pulse starting in Week 26 marks a change from 55% RH to 60%RH and back again, to see how the front panel meter compares with the low end lab-grade hygrometer in the other side of the basement near the Hobo datalogger on the water inlet; they’re all off by a bit, but well within their expected tolerances. The 5% RH height of the step suggests a good match between their incremental calibrations.

It seems dehumidifiers last a few years, no matter which Brand Name you’ve decided to trust, so there’s not much point in developing a deep emotional attachment.

For the record, the old dehumidifier sported a GE label:

GE Dehumidifier label

The new one says Frigidaire on the front, but the label says Electrolux:

Fridgidaire – Electrolux Dehumidifier label

As it turns out, Electrolux bought Frigidaire a while ago, then absorbed GE’s appliances in 2014, so they’re all one big happy family now.

The various names notwithstanding, a recall notice suggests Gree Electric actually makes all the dehumidifiers badged with Brand Names you might think represent something significant.

2015-08-01
Silhouette Glasses: Temple Re-repair

This was not the failure mode I expected:

Silhouette temple – failed repair

As failures go, that one’s survivable; slightly larger epoxy dots should do the trick:

Silhouette temple – re-repair

The other temple worked loose inside the brass tube and rotated freely, so I yanked it out, bashed the tip slightly flatter, and epoxied it back in place, along with overcoating the epoxy dots on the lens to forestall another failure.

This has obviously blown right by the point of absurdity, but …

2015-07-27
Sony 64 GB MicroSDXC Card: Speed Failure Redux

After about 1 TB of data spread over three months and maybe 100 bike rides, the second Sony SR-64UY 64 GB MicroSDXC card I bought last summer has failed… barely two weeks inside the one year warranty.

As with the first card, this one works fine except for the speed: it cannot record at 1920x1080p @ 60 fps. The only indication comes from aiming another camera at the display to capture the failure as it happens.

Just before the failure:

HDR-AS30V – MicroSDXC failure – 1

It’s taking stock of the situation:

HDR-AS30V – MicroSDXC failure – 2

Presumably, it’s patching up the abruptly terminated file:

HDR-AS30V – MicroSDXC failure – 3

Another box is on its way to Sony Media Services…

Over the last year, the price of an almost certainly genuine Sony SR-64UY Class 10 UHS-1 MicroSDXC card has dropped by 2.2 dB: $40 to $24. Now, however, the SR-64UY is the “old model”, so you can pay $30 (-1.3 dB) for an SR-64UY2 rated at 70 MB/s transfer speed (up from 40 MB/s), albeit with no change in the card’s speed class.

Huh.

Both cards failed after writing 1 TB of data (give or take maybe 20%) in 4 GB chunks over the course of 100 recording sessions. The cards still work, in the sense that they can store and accurately retrieve data, just not at the Class 4 (not Class 10) speed rating required by the HDR-AS30V at 1920x1080p @ 60 fps.

The table in the Wikipedia Secure Digital article says Class 4 = 4 MB/s, which is slightly faster than the camera produces 4 GB files in 22:43 min:sec = 3 MB/s. A Class 10 card should write at a sustained 10 MB/s, so the SR-64UY write speed has dropped by at least a factor of 3 from the spec. I’d expect the root problem to be the error correction / block remapping / spare pool handling time has grown as the number of failed blocks eats into the card’s overcapacity, but I have no inside information.

When the replacements slow down, I’ll see how they work as Raspberry Pi memory…

2015-07-10
Houses Are Trouble: Terwilliger House Windows

Imagine “updating” these windows with modern high-efficiency glass:

Terwilliger House – parallelogram windows

That’s the end wall of the 1738 Terwilliger House on the Locust Lawn site. I’m sure the woodwork doesn’t date back that far, but the glazier demonstrated genius-level mastery.

We were on a fascinating behind-the-scenes tour, marred by a visitor who knew the rules about not touching the exhibits didn’t apply to her. My parents ran a restaurant / gift shop and, to this day, my hands automatically find their way into my pockets when I enter a store, let alone a museum.

2015-07-05
Splitting Banana Skins

Over the last year or two, we’ve had several bunches of bananas that split their own skin:

Banana with split skin

Apart from the slightly dried section directly under the split, the banana is perfectly edible.

Not sure what it means, other than that we‘re probably not causing it. We don’t recall it happening in the Good Old Days.

Cavendish bananas will probably vanish in a few decades, so enjoy ’em while ya got ’em.

2015-05-16
Always Sign Your Work

Quite some years ago, I added a wire shelf to the bottom of the “pantry” closet to hold odds-and-ends. The most recent deep-cleaning cycle required removing the shelf, which required removing the mounting brackets to get the fool thing out of the closet.

The backside of one bracket shows I had a bit of trouble matching the mounting holes to the wall anchors:

Pantry wire shelf brackets – overview

The lower bracket bears some advice from my Shop Assistant:

Pantry wire shelf brackets – detail

Check thrice
Measure twice
Cut once

From what little we hear these days, she’s learned the value of always checking her work…

And she signs it, too.

2015-05-10
Kenmore 158: Large(st) Spool Holder

Large quilting projects require lots of thread, beyond the capacity of the previous spool adapter, so we came up with a different solution:

Large spool holder

These are cheap & readily available from the usual sources, but recent reviews indicate that the “metal” base has become plastic and the build quality isn’t anything to rejoice over. My feeling is that if it’s going to become a shop project anyway, I should just conjure something suitable from the heap.

The base is a random plastic project box that came with a flimsy sheet-steel top, which I replaced with a rectangle of 0.1 inch = 2.5 mm aluminum plate for more heft. The box is filled with 1.5 pounds of wheel weights, so it’s not going anywhere on its own. The silicone rubber feet probably don’t add much to the project, but why not use ’em?

The feed hook started life as copper-flashed welding filler rod, smooth to the thread and pleasant to the eye, sitting in a hole drilled into a stainless steel 10-32 screw. It’s long enough to feed the thread just above the Kenmore’s top surface. A hook works better than an eyelet: just pass the thread over the hook and you’re done.

The central shaft is a wood dowel, shaped & sanded on the (metal) lathe, held in place by another 10-32 screw. Inside the spool sits a length of “3/4 inch” CPVC pipe (ID = 0.7 inch, OD = 0.875 inch, gotta love those plumbing measurements) that’s a sloppy fit in the just-over 1 inch spool ID.

The smaller spools fit directly on the dowel, perhaps atop the CPVC sleeve.

This seems to work OK, but I’m going to trim the dowel down to just over the length of the spool, so the thread will feed without touching the wood. I thought stacking the smaller spools atop the CPVC sleeve made sense, but that turned out to not be the case.

Took about an hour to conjure with found materials and without a hint of 3D printing…

2015-05-08