Archive for category Home Ec

Amazon Unit Price Anomalies

Backstory: we get Kirkland almond butter from Amazon, because it has consistently good quality at a reasonable price. Kirkland being the Costco house brand, we’re obviously buying it from someone arbitraging the Costco price. The nearest Costco is over an hour away, so spending $60 for a membership (*) just to get almond butter doesn’t make sense.

However, I’ve discovered Amazon’s “buy it again” prompting generally doesn’t offer the best deal, so I start each purchase cycle with a general search. The current results proved interesting (clicky for more dots):

Amazon - unit pricing FAIL

Amazon – unit pricing FAIL

Let’s go through this slowly.

The first result shows the “unit pricing” isn’t done automatically, because it’s completely wrong:

Amazon - unit pricing puzzle

Amazon – unit pricing puzzle

I can figure half of $27.52 isn’t $9.17, but dividing $27.52 by three really is. Dividing by two, the actual size, says the correct “unit price” is $13.76 each. Oddly, searching a day later showed the price went up to $28.69, with the same incorrect divide-by-three unit pricing error.

The “Amazon’s Choice” result simply means a bunch of people bought from that listing, not that Amazon has an actual involvement apart from raking in their take. There’s no unit pricing, but each jar works out to $13.59.

The last result confirms Amazon’s unit pricing bogosity by (correctly!) dividing $26.23 by two, but then claiming the unit price is “per ounce”.

Weirdly, everybody selling the two-pack prices it that way:

Amazon - unit pricing consistent FAIL

Amazon – unit pricing consistent FAIL

We’re surely not looking at half a dozen heads of the same hydra, so this bogosity derives from the commingled UPC (ASIN, whatever) warehouse stock technique giving Amazon a way to avoid responsibility for counterfeits. Somebody (presumably at Amazon) selected the calculation to produce the unit price, but fat-fingered “per ounce” rather than “per each”, and now vendors just bid for that UPC without sweating the details.

You’d (well, I’d) think a bit of Amazon’s much-vaunted machine learning would go a long way toward sorting this out, but it doesn’t.

Word: any sufficiently advanced stupidity is indistinguishable from malice.

(*) Right now, it’s $8.79 direct from Costco online and their 5% non-member surcharge seems survivable.



American Standard Kitchen Faucet: Ceramic Valve Cores

The  ceramic valve core from our kitchen faucet certainly qualifies for a spot on the bottom flange of the I-beam across our basement serving as a display case / collection area for shop curiosities, mementos, and the like. I am, if nothing else, a creature of fixed habits, because the spot where the core belonged already had one:

American Standard Ceramic Faucet Valve Cores - old vs new

American Standard Ceramic Faucet Valve Cores – old vs new

The core on the left dates back to the 2016 replacement, so they’ve apparently decided plastic will work fine for the handle socket.

Having the ceramic core fail after two years suggests the manufacturing process needs attention, though. I can still wring the slabs together, though, and they’d need a drop of oil to serve as bearing surfaces.




Adulting 101

The library runs courses teaching useful skills:

Adulting 101 - Car Maintenance

Adulting 101 – Car Maintenance

The classes cover the basics of home finance, cooking, sewing, and suchlike.

I could have used a few Adulting courses, back in the day.

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Halogen Desk Lamp Conversion: Preliminaries

A discarded 20 W halogen desk lamp arrived in the Basement Laboratory for rebuilding:

Halogen Desk Lamp - head layout

Halogen Desk Lamp – head layout

An incandescent bulb doesn’t care about AC or DC, so a simple transformer also serves as a counterweight in the base:

Halogen Desk Lamp - 12 V 20 W transformer

Halogen Desk Lamp – 12 V 20 W transformer

I might replace it with some steel sheets, although I have no immediate need for a bare transformer.

A case adds 19¢ to each 10 W 300 mA LED driver:

Halogen Desk Lamp - 10 W LED driver innards

Halogen Desk Lamp – 10 W LED driver innards

Nice strain relief on those line-voltage wires, eh?

A simple test setup with three 3 W COB LED panels:

Halogen Desk Lamp - 3x3W COB LED test

Halogen Desk Lamp – 3x3W COB LED test

I clamped them to the aluminum sheet for heatsinking before I lit ’em up. The circles traced directly from the lamp’s hardware give some idea of the eventual layout.

I have more-intense LEDs, but spreading the light over a larger area should work better for the intended purpose. These are pleasant warm-white LEDs, too.

The fourth LED raised the forward voltage beyond the supply’s 42 V maximum, causing the supply to blink on and off.

Much to my surprise, the driver has plenty of 60 Hz ripple:

COB LED 3x3W - 10 W driver - 100 mA-div 10 V-div

COB LED 3x3W – 10 W driver – 100 mA-div 10 V-div

The top trace averages 280 mA and the bottom trace 32 V, so the LEDs run at 9 W = 3 W apiece, as they should.

Now, for some metalworking …


Pi-Hole with DNS-over-HTTPS

With none other than Troy Hunt recommending Pi-Hole, I got a Round Tuit:

unzip -d /tmp
sudo dcfldd status=progress bs=1M of=/dev/sde if=/tmp/2018-06-27-raspbian-stretch-lite.img

Raspbian now arrives with ssh disabled, so the first boot requires a keyboard and display:

Pi-Hole first boot wiring

Pi-Hole first boot wiring

Then do some configuration required to get a fresh Raspberry Pi ready for remote access:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install screen iotop
sudo raspi-config   # enable ssh
ssh-keygen -t rsa
cd ~/.ssh
cp -a /my/public/key authorized_keys
chmod go-rwx authorized_keys
sudo nano /etc/ssh/sshd_config  # unusual port, no root login, etc
sudo service ssh restart

As the good folks at Pi-Hole say, “Piping to bash is controversial, as it prevents you from reading code that is about to run on your system.” I took a look, it’s beyond my comprehension, so just get it done:

curl -sSL | bash

Configure Pi-Hole:

  • Static IP:
  • DNS using, say, Cloudflare’s
  • DHCP turned off, which is the default

Configure the router’s DHCP to hand out the Pi-Hole’s IP, with, say, as a backup.

Boot a few random PCs and whatnot to verify it works as expected, which it did the second time around, thus this particular post.

Install the Cloudflare Argo Tunnel dæmon, approximately according to suggestions:

mkdir Downloads
cd Downloads/
tar zxvf cloudflared-stable-linux-arm.tgz
sudo mkdir /opt/cloudflare
sudo cp cloudflared /opt/cloudflare/

Start the daemon from within a screen session, also as suggested:

sudo /opt/cloudflare/cloudflared proxy-dns --port 54 --upstream --upstream
INFO[0000] Adding DNS upstream                           url=""
INFO[0000] Adding DNS upstream                           url=""
INFO[0000] Starting metrics server                       addr=""
INFO[0000] Starting DNS over HTTPS proxy server          addr="dns://localhost:54"

Contrary to the suggestions, you can configure Pi-Hole to use the DoH tunnel (or whatever it’s called) by tweaking its upstream DNS configuration:

Pi-Hole - Cloudflare DNS config

Pi-Hole – Cloudflare DNS config

Then set up systemd to start the daemon automagically:

sudo nano /etc/systemd/system/dnsproxy.service

Because I put the daemon in /opt/cloudflare, that file differs slightly from the suggestion:

Description=CloudFlare DNS over HTTPS Proxy

ExecStart=/opt/cloudflare/cloudflared proxy-dns --port 54 --upstream --upstream$

And then It Just Worked.

Controversies over the ethics of ad and tracker blocking will go nowhere here, as I’ve cleaned out enough Windows machines to have absolutely no sympathy with the unholy spawn of adtech (not just the company, which I didn’t know existed until just now, but, yeah, them too).


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Monthly Science: Cheese Slicer Epoxy vs. Water, Continuing

The epoxy coating on our cheap aluminum (?) cheese slicer continues to corrode (clicky for more dots):

Cheese slicer - epoxy failure - front

Cheese slicer – epoxy failure – front

The back side:

Cheese slicer - epoxy failure - rear

Cheese slicer – epoxy failure – rear

The epoxy coating remains intact, although I expect it’ll break through as the corrosion products swell underneath.

For whatever it’s worth, I applied the epoxy almost exactly one year ago.

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Maximum Strength Homeopathic HGH: Not

Spotted at an exhibition for Olde Fartes:

Somaderm homeopathic HGH

Somaderm homeopathic HGH

I think they just blew up the bottle label to human size, with no attention to the resulting pixelation.

One can find Somaderm on the Interwebs, which leads to the “Active Ingredients” list:

Somaderm homeopathic HGH - Active Ingredients

Somaderm homeopathic HGH – Active Ingredients

Looking up their NDC number helps translate the bullshit Latinesque nomenclature:

  • Glandula Suprarenalis Suis = boar adrenal glands
  • Thyroidinum = cow thyroid glands
  • Somatropin = human growth hormone

They’re exceedingly proud of that NDC number, touting “SOMADERM Gel is the only transdermal, FDA registered product”. Indeed, it’s registered, about which the FDC has this to say:

Assigned NDC numbers are not in any way an indication of FDA approval of the product.



With that in mind, consider the dilutions:

  • Glandula Suprarenalis Suis = 1 part per million
  • Thyroidinum = 10 part per billion
  • Somatropin = 1×10-30 = there are no words

Homeopathic “drugs” never list the starting concentration or amounts in the product, but diluting something by a factor of ten-to-the-thirty ensures not one single molecule of the original compound will make it into the bottle. This, of course, means the HGH is at “maximum strength”, in the homeopathic way of magical thinking.

You’ll surely find some molecules of pig brain and maybe even a few molecules of cow glands, but I suspect they’re not buying the “active” ingredients in shipping container lots. In round numbers, one pig adrenal, one cow thyroid, and one drop of actual HGH would supply their needs well into the future.

I would like to see how they dilute those ingredients, because I doubt they have legions of trained homeopaths succussing bottles against elastic surfaces.

Of course, such dilution requires careful attention to detail, lest a stray molecule make its way into the final product, which surely justifies the punch line:

Somaderm homeopathic HGH - Price

Somaderm homeopathic HGH – Price

There is also a $150 “Membership Price”, suggesting a multi-level marketing scam running in parallel. Some rummaging on their website reveals cryptic phrases confirming the suspicion: “Be the change that will inspire others to follow” and “Information on how to become a distributor“.

Ya gotta admire ’em for not even blinking.

A note on commenting: there is zero evidence of efficacy¸ so don’t even try to advocate homeopathy. If it worked, it’d be medicine, not a MLM scam.