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

The Machine Stops

As foretold by E. M. Forster in 1909, we have two exhibits of the machine grinding to a halt.

Amazon sent one of their prescription savings cards, followed a few days later by a note:

We recently mailed you a physical copy of your Amazon Prime Rx savings card, and are writing to inform you that the BIN listed on your Prime Rx card printed incorrectly. The correct BIN is 019363.

So I wrote the corrected number on my card, not that I will ever use it:

Amazon RX – BIN error

Although the BIN (whatever that stands for) is a numeric value, it’s not treated as a number by whoever reads it. I’d lay money down that the source code’s formatting string changed from %6d to %06d or the equivalent in whatever fancy language they use nowadays.

The Social Security Administration sent me an email telling me to check a corrected version of a statement they sent a few months ago. Unfortunately, attempting to do so while writing this post produces a heads-up notice:

We apologize for any inconvenience accessing my Social Security. We are aware of some technical difficulties and are working on them at this time. We appreciate your patience as we work to solve the problems as quickly as possible.

Attempting to sign on seems to proceed normally, until this technical difficulty popped up:

We’re Sorry…
There has been an unexpected system error.
Your login session has been terminated. For security reasons, please close all of your internet browser windows.

The first statement put my nearest Social Security office 130 miles away in Wilkes Barre, PA. The corrected statement put it back where it belongs, in the hot urban core of Poughkeepsie.

Perhaps an off-by one error in the database lookup?

As far as I can tell, the world now depends on software nobody can understand or control.

2021-12-08
Humana Unsubscribe FAIL

Quite some years ago, I had a health insurance plan with Humana, although I gave it up because the premiums seemed entirely disproportional to the benefits. They have continued to bombard me with emails telling me how wonderful they are, with an obligatory sentence at the bottom:

If you do not want us to contact you by email, you can unsubscribe from our online Humana community.

I do not know anything about this “community” of which they speak, other than that they seem to think I want to be part of it.

Clicking on the “unsubscribe” link takes me to a page at their randomly named email service, whereupon I check the “don’t send me anything” box and click the “Submit” button:

Humana Unsubscribe failure

Did you see the green text near the middle, where my email address should be? Apparently somebody misconfigured the email script to not include the actual address; the %25 gibberish seems to be encoded percent signs, so it may be one of those too-many / too-few / wrong-kind of character escapes.

Just a typo that could happen to anyone. Right?

Having once been a customer, I still have an account, but there is no way to control / shut off those messages. Not being a current customer, however, I cannot use their chat interface, which would likely not be productive. I am unwilling to wait on hold for an hour, because I know my call is not valuable to them, and their customer service rep wouldn’t be competent to solve the problem anyhow.

Fortunately, I can set up a filter to route their emails directly to trash.

2021-12-03
Walker Leg Shortening

While looking for something else, Mary came across a walker in the attic and mentioned that, if she ever had to use it, the shortest position of the adjustable legs would put the hand grips too high for comfort. Maybe they

Well, I can fix that:

Walker shortening – hole indexing

The holes are an inch apart, so I clamped the V blocks parallel to the X axis on the drill press, zeroed the X axis knob, slid the leg to get the drill bit into the last hole, clamp in place, crank the table an inch, then use a step drill to start the hole:

Walker shortening – hole drilling

The holes are just slightly larger than the 1/4 inch step on the drill, so the twist drill cuts them to size.

A tubing cutter sliced an inch off all four legs and all four frame tubes:

Walker shortening – latch relocation

The white plastic fitting in the frame tube prevents the legs from rattling, but I had to drill another hole to move the latch button, too.

With a bit of luck, we’ll never need the thing.

2021-12-02
Incandescent Bulb Lifetime: Also Better Than Average

This bulb spent the last seven-plus years of its life lighting the front bathroom:

Dead incandescent bulb – 7 years

The green corrosion around the tip seems strange, given that we don’t use the tub or shower in that bathroom, and I’m pretty sure it wasn’t the cause of the failure.

My stock of incandescent bulbs will eventually run out; I must figure out how to light the deaders in an attractive manner.

2021-11-30
Lyme Disease, Now With Bonus Babesiosis

Two weeks of doxycycline should kill off all the Borrelia bacteria responsible for Lyme disease, but a blood test shows the antibodies:

Lyme test – 2021-11-10

Those antibodies will gradually disappear during the next few months and, unfortunately, a past Lyme infection does not prevent future infections.

The tick also injected Babesia parasites which do not respond to antibiotic treatment:

Babesia test – 2021-11-10

The “titer” refers to the dilution required to produce a negative test result, with the 1:64 reference titer representing six successive 50% dilutions. My blood required ten 50% dilutions to produce a negative result for the IgG antibodies and (presumably) six 50% dilutions from a 20% base for the IgM antibodies.

As I understand the situation, IgM antibodies appear promptly upon infection and IgG antibodies follow along later, so my reaction to the Babesia infestation was ramping up after two weeks.

In the Bad Old Days™, quinine was the go-to treatment for parasitic infections, but it has a host of horrific side effects at the dosage required for traction against actual diseases; tonic water ain’t gonna get you where you need to go.

The new hotness is atovaquone, arriving as 100 ml of a yellow liquid with the consistency of latex paint, (allegedly) the taste of “tutti fruitti“, and a price (modulo your drug plan) making inkjet printer ink look downright affordable. You might expect to get a 5 ml measuring spoon along the the bottle, but suffice it to say it’s an exceedingly good thing I’m well stocked for printer cartridge refilling.

All of the diseases and drugs list “fatigue” / “drowsiness” / “malaise” as symptoms / side effects and I’m here to tell you knocking off a couple of hours in the recliner during the day does nothing at all to disturb another nine hours in the sack overnight.

A few weeks of low productivity in the Basement Shop™ will definitely count as a successful outcome.

Protip: We need permethrin spray. Lots permethrin spray.

2021-11-24
CFL Lifetime: Better Than Average

Although compact fluorescent lamps have fallen out of favor, I’m burning through a box of the things donated by a friend who upgraded to LEDs and figured I could put them to good use. In general, complex electronic doodads (like CFL or even LED lamps) used in hostile situations (like an ordinary downlight fixture) seem to fail too quickly to justify the power savings; searching for “cfl fail” will produce some evidence from around here.

One of the downlights in the Basement Office just killed this specimen:

Dead CFL – detail

Much to my surprise, however, it survived for more than five years:

Dead CFL – over 5 years

The previous CFL bulb in that fixture lasted only two years, so their average lifetime is entirely too short.

A taller bulb does a better job of lighting up that corner, although it started with enough power-on hours to suggest it won’t survive for another five years:

Dead CFL – replacement

The ghostly humps above the overexposed glare are the long CFL tubes reflected inside the Pixel’s camera optics.

I didn’t see much point in nailing a ceiling to too-low floor joists.

2021-11-18
Shopvac QSP Motor Commutator Cleaning

The Greatest Shopvac emitted an intense smell of electrical death while inhaling fuzzballs from the Basement Shop stairs, prompting me to tear it down. For the record, it’s a Genuine Shop·Vac QSP 10 (Quiet Super Power):

Shopvac QSP – label

Removing the handle and upper plate reveals a slab of (presumably) sound-deadening foam over the motor cooling fan. As far as I can tell, the last job this vacuum had before the previous owner discarded it was inhaling drywall dust without a filter:

Shopvac QSP – upper sound baffle

Flipping the motor assembly over and removing the bottom plate revealed a pair of equally solidified foam slabs baffling the main exhaust path:

Shopvac QSP – sound baffle foam

They eventually became Clean Enough™ after protracted rinsing, so maybe the thing now runs as quietly as the name would lead you to believe, if you believed in names.

Disconnecting and extracting the motor revealed the razor-sharp impeller disk. A shop rag prevents lacerations while torquing off the nut holding it to the shaft:

Shopvac QSP – impeller nut

Rust on the washer below the impeller, along with the layer of caked white cement, suggested water accompanied the drywall dust:

Shopvac QSP – impeller washer

Gentle suasion from the Designated Prydriver eventually eased the washer off the shaft and freed the motor:

Shopvac QSP – motor brush layout

It’s an old-school series-wound brushed universal motor. The plastic plate in the middle of the picture has a helical spring pressing the carbon brush against the commutator:

Shopvac QSP – motor brush detail

The rotor turned … reluctantly with the brushes in place and spun freely without them, suggesting the horrible smell of electrical death came from arcing across the gunk accumulated on the commutator:

Shopvac QSP – commutator as found

Many iterations of diligent scrubbing with denatured alcohol on cotton swabs and old t-shirt snippets got rid of the crud, although that commutator will never look all shiny-clean again:

Shopvac QSP – commutator cleaned

At least the brushes aren’t glued to it!

Reassembly is in reverse order, although I took the liberty of splicing a few inches of wire into the switch leads, because I’m not working under factory conditions with all the proper assembly fixtures:

Shopvac QSP – extended wires

The motor passed the smoke test and no longer smells like death, so it’s at least as good as it ever was.

It may run quieter with clean foam baffles, but I still turn off my power ears or don hearing protection when I fire up any shop vacuum.

2021-11-11