Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
Y’know how some folks say they don’t wear a seat belt because they want to be thrown free in a crash? Here’s how that works in actual practice.
The air bag fires as the front bumper begins to deform and your body rises off the seat. Because you’re not belted in, the bag boosts your upper torso against the roof liner, bounces your head off the sunshade and bezel, then feeds you directly into the windshield glass.
Laminated glass doesn’t disintegrate, so your skull probably won’t completely penetrate the windshield. You’ll lose some scalp, though, as you slide down the crumbling glass and wedge above the dashboard.
Even if you survive a broken neck, the ensuing brain trauma means you won’t be the same person ever again.
News flash: massive brain trauma does not make you a better person.
Before laminated windshield glass became mandatory, your head would completely penetrate the windshield. Here’s what happened in 1937, from the incomparably grisly — And Sudden Death by J. C. Furnas:
Safety Glass Windshields
I read one of the many Reader’s Digest editions of that article during my formative years. Probably the one in October 1967, if a bit of Google-fu serves me right. You can’t get reprints of it from RD any longer, it seems.
However, unbelievably, while I was composing this post, I checked eBay and found a typewritten copy of the article, signed by Furnas, with 38 minutes remaining in the auction. I was the only bidder: for nine bucks (delivered) it’s mine.
Most likely it’s a publicity / fundraising copy, because the handwritten notation on the first page reads:
With best
regards to
[name]
J. C. Furnas
Oct 20, 1947
Those SUVs reside in the junkyard along the Dutchess Rail Trail near Creek Road, where I might get a new seat to rebuild my comfy office chair this spring.
Just got two eyeglasses from a different supplier halfway around the planet, with satisfactory results.
The frames have the largest lenses I could find that weren’t totally dorky; I still want slightly taller lenses, but that’s not the style these days. Their 35 mm lenses are slightly larger than the 35 mm lenses from previous vendor, but IMHO still not quite tall enough for progressive bifocals. The closeup curves seem to start lower on the lens, which is fine.
The 20 mm nose bridge is a Good Thing and made the nosepiece adjustments much easier than before.
Metal Eyeglasses-Vincent
Dimensions
Width 137 mm
Earpiece 144 mm
Lens width 50 mm
Lens height 35 mm
Nose bridge 20 mm
I used a 60 mm Near Pupillary Distance (for the bifocal lens area), which worked fine, although 1 mm might be better.
The regular glasses have the usual options and work fine. The 1.6 “super thin” refractive index (vs 1.5 “regular” in the sunglasses) makes the lenses noticeably thinner than the sunglasses, but I’m not sure it’s worth the upcharge.
- I use my Glasses for: Progressive - Bifocal without a line
- Lens upgrades 5: Progressive Lens (no line)
- Right Sphere(SPH): -3.50
- Right Cylinder (CYL): +0.50
- Right Axis: 180
- Right Addition (near) ADD: +2.25
- Left Sphere(SPH): -3.50
- Left Cylinder (CYL): +0.75
- Left Axis: 155
- Left Addition (near) ADD: +2.25
- Pupillary Distance (PD): 62
- Near PD: 60
- Lens upgrades 3: Super Thin (1.6)
- Eye Protection and Eyeglasses 1: Anti-Scratch
- Eye Protection and Eyeglasses 2: Anti-Reflective
- Eye Protection and Eyeglasses 3: UV Coating
For the sunglasses I tried Old School with-a-line bifocals and, frankly, don’t like them much at all. The line is very distracting in sunlight, which is where I wear sunglasses. Good news: the line falls directly across the fairing on my bike, so I can see the “dashboard” on the handlebars quite clearly. Bad news: the correction is a bit much for the automobile dashboard and, unlike the no-line bifocals, I can’t tune for best picture by nodding my head.
Their 80% gray tint is significantly lighter than the previous vendor’s 80%; next time go for 90%. Good news: unlike the previous vendor, these folks have no trouble with AR/UV coatings over a tint.
- I use my Glasses for: Bifocal - Both distance and reading with a line
- Lens upgrades 4: Bifocal Lens (with line)
- Division of lenses: 70% Distance - 30% Reading
- Right Sphere(SPH): -3.50
- Right Cylinder (CYL): +0.50
- Right Axis: 180
- Right Addition (near) ADD: +2.25
- Left Sphere(SPH): -3.50
- Left Cylinder (CYL): +0.75
- Left Axis: 155
- Left Addition (near) ADD: +2.25
- Pupillary Distance (PD): 62
- Near PD: 60
- Lens upgrades 1: Standard (1.5)
- Eye Protection and Eyeglasses 1: Anti-Scratch
- Eye Protection and Eyeglasses 2: Anti-Reflective
- Eye Protection and Eyeglasses 3: UV Coating
- Tint Key: Grey 80%
- Eye Protection and Eyeglasses 4: Color Tint
So I swapped in the snow tires and did the fall oil change a few days ago. Everything went smoothly, although the oil filter, as usual, blooshed oil over the front of the engine and, despite my padding the area with rags, onto the exhaust plumbing.
Digression: I don’t understand why the Toyota engineers felt they had to tuck the oil filter below the exhaust header, behind the front downpipe, and over the flexible coupling to the forward cat converter, with the mounting tube pointed upward. It might have something to do with their rotating the entire engine rearward to get a lower hoodline. It seems to me that angling the filter so it can’t drain and must dump its contents atop the exhaust system isn’t Good Design; I’ve been muttering about it for the last decade.
Anyway, the new filter screwed on easily, its seal ring (seemed to) seat against the block, and one final turn snugged it up just fine. The last fraction of that turn felt gritty, as though part the shell kissed the block, but I attributed that to the fact I was using a different filter style.
I added the usual 5 quarts of oil, wiped up the spills, cleaned off the exhaust pipes, declared victory, called it a day, and put away the tools. Later that evening, I checked for leaks, found nothing, and we drove to a meeting about 12 miles away. As you might expect, the van smelled strongly of hot oil: you cannot wipe all the oil off those pipes.
Oil trails on driveway
The next morning, Mary drove to an all-day class about 15 miles away and, about noon, I rolled out my bike to go grocery shopping… only to discover what you see in the picture (minus the sawdust patch) on the driveway.
This is what we call in the trade A Very Bad Sign.
There are three oil tracks:
Right-front track = outbound to evening trip
Rightmost heavy track = return
Leftmost track = outbound to morning trip
Now, the fact that there’s no huge oil slick means the drain plug is in place and properly sealed. The oil evidently leaks out only under pressure, so the filter isn’t sealed against the block. This can be due to a number of causes, the most common of which is leaving the rubber ring from the old filter stuck to the block. I checked the old filter, which was still in the trash: the seal was still in place, so that wasn’t contributing to the problem.
Regardless, the car was bleeding to death. I called Mary and she reported a dry dipstick.
So I loaded a 5-quart jug of oil into the right pannier, dumped all the tools that might possibly come in handy into the left pannier, topped both off with many rags, stopped at an auto parts store along the way for a new filter, and rode those 15 miles at a pretty good clip. When I got to the parking lot, it was easy to find the van: simply follow its trail. The van sat atop a disturbingly large slick, evidently caused by oil draining off every local minimum inside the engine compartment and under the forward half of the chassis.
The filter was still firmly screwed in place, but when I got it off and compared it with the new filter, they were different: the offending filter was slightly larger in diameter and the threaded hole was noticeable larger. Although it threaded on, the threads weren’t properly engaged, the larger diameter shell did hit the engine block, and it most certainly wasn’t sealed properly.
I installed the new filter, poured in 3 quarts to the get the oil level midway into the dipstick’s OK range, wiped off some of the oil that coated essentially every part of the engine compartment, and we drove home trailing a cloud of hot oil fumes.
As it turned out, the old filter was the same brand as the one that didn’t seal, but with different numbers and a different prefix: the correct filter is a 3614, the wrong one was 3593. Of course, the boxes and illustrations are identical, with slightly different contents. I’m sure they’re adjacent on the shelf and migrate into each other’s slot. It’s worth noting that the filter I bought while on the way to fix the problem was a different brand sporting a part number totally unrelated to 3614.
The butt end of the van was covered with oil, as though the droplets blew out under the chassis and got sucked up against the rear surface; the window was a mess. I sprayed on stout detergent and wiped it clean, but I think we must treat the poor thing to an all-over car wash with the special undercarriage scrub option.
No harm done, as nearly as I can tell, although it’s an exceedingly good thing we weren’t driving off to the grandparents!
My shop assistant bears most of the hair in the household, so it seemed entirely appropriate that she clear the clog from the shower drain. She says she’s going to take a picture of the hairball and show her friends what her parents make her do…
I pointed out that plumbers are ecstatic when they get a call for this sort of problem and will charge maybe 150 bucks to make the clog Go Away. When she’s writing the check, she can make whatever choice she wants.
For now, this is how it gets done; the snake hangs on the garage wall.
After the hinge repair described there, those old sunglasses have been working fine and I use them regularly. The screw recently worked its Loctite loose and was held in largely by blind faith.
It’s obvious why:
Sunglass hinge screw – loose
A tiny dab of JB KWIK should solve that problem for the foreseeable future:
Sunglass hinge screw – epoxy
In the highly unlikely event I must remove that screw, I’ll just refer to this picture and mill the epoxy out.
So there you have it: the bugs that killed three months.
We’ve gone a month without a bite and are only now restoring furniture to the bedroom. Each piece goes up on powder traps and gets a week in isolation to reveal any bugs before we reload the drawers with clean clothing. After vacuuming and washing there shouldn’t be any bugs left on the furniture, if the piece had any to begin with. Almost certainly that is wasted effort, but …
Maybe next year we’ll buy new chairs and a couch for the living room. For sure, they won’t have plush, overstuffed upholstry.
With any luck (and the regular use of a hot box disinsector), you won’t go through what we did.
However, should you discover a row of bites across your body, the actions you take during the next few days will determine the level of catastrophe during your next year. The problem will not go away by ignoring it; if you get a breeding population going in your house / apartment / condo, you will definitely need a commercial pest-control service.
If you think tossing out some furniture to get rid of a few bugs is expensive: just wait.
Now, having seen what we’ve been living through, you might ask yourself
Wouldn’t It Be Nice If there was some way to be absolutely sure that mumble does not happen to me?
There isn’t, but you can stack the odds in your favor by disinsecting everything that enters your house. In particular, when you return from a trip, you must treat your luggage with the same casual regard as you apply to any lump of highly radioactive waste.
Because all bed bug stages die when exposed to temperatures over 45°C (113°F, which I round to 120°F), the simplest way to ensure that you’re not bringing any passengers home is to heat your luggage / packages / clothing / whatever to an internal temperature around 120°F, then let it soak for maybe an hour to ensure all the occupants get the message.
What you need is a box that gets hot on the inside, but not hot enough to set your luggage on fire. As with all things sold for bed bug problems, the commercial solution seems grossly overpriced for what looks like an uninsulated ripstop nylon bag containing a rack, a heater, and a fan.
It should come as no surprise that I built something that’s bigger, uglier, and harder to use… but it produces data and you can do science. And, with liberal use of my parts heap, the overall price is maybe 10 dB down from the commercial version…
Hot box exterior
I figured that this widget is going to be a major part of our lives from now on, so a foldable / storable heater wasn’t particularly useful. In point of fact, we’ve been using it heavily and I don’t expect that to stop any time soon.
Inside, I used lengths of wire shelving to support the thing-to-be-baked. After we’ve used it a bit more, I’ll conjure up permanent supports for the second level shelving (stacked on the right of the exterior picture); right now, they’re supported on wood blocks as needed.
Hot box interiorHot Box – Dimension sketch
The interior dimensions work out to 34x22x24 inches: it’s made from a single 4×8 foot sheet of insulating board. Here’s my working sketch showing how the parts lay out and fit together. (clicky the pic for more dots).
The only waste is the 1-inch strip along the right edge; the slab I bought came with a molding imperfection, so discarding that edge was OK.
I cut the sheet into four 2×4 foot strips, cut a 13-inch strip off each plank, then trimmed the 1 inch waste. That seemed less prone to catastrophic blundering than (trying to) make a pair of 8-foot cuts and whack each resulting strip in quarters. An ordinary razor utility knife worked fine, although I found that making two passes along each cut produced cleaner results than trying to do it all in one.
I assembled it with the heavy / shiny aluminum foil side inward, although I doubt it makes any difference. Cover all the edges with tape, tape all the joints both inside and outside, and it becomes a nice rigid box when you’re done. Pay attention to getting the sides at right angles; I used a framing square.
The board allegedly has an insulating mojo of:
R = 6.5 ft2 • h • °F/Btu
Figuring a surface area of 32 ft2 and a temperature differential of 120 – 60 = 60°F, the box should require 295 BTU/hr = 87 W to maintain that temperature.
Which, as it turns out, is pretty close to how it worked out:
Hot Box – Temp vs Time – First light
The lower curve shows a 60 W bulb with a 10 W 120 VAC fan heats the interior to a bit over 100°F in 100 minutes, where it looks to be stabilizing. That was the first test and showed that I was on the right track.
The second test, with a pair of 60 W bulbs and the fan produced the two upper curves: one for air, the other inside some cloth jammed inside a plastic bucket to simulate a (tiny) suitcase. The combined 130 W heats the box over 150°F in two hours, with the somewhat insulated bucket trailing neatly behind as you’d expect.
Without opening the box, I connected the bulbs and fan to a Variac plugged into my Kill-A-Watt meter and dialed it for 100 W total dissipation. The temperature fell to slightly over 130°F in 80 minutes and looks like it would stabilize near there.
Ambient temperature was 67°F, so
R = 32 ft2 • 67°F / (341 BTU/hr) = 6.3
Close enough, I’d say. Given those few data points, it looks like the temperature sensitivity around 130°F is 0.7°F / W. [Update: typo in the equation. Doesn’t change the answer much at all.]
I swapped in a 100 W bulb, removed the Variac, and heated the cushions from my office chair.
Hot Box – Chair cushions
One thermocouple is hanging in mid-air, the other is wedged inside one of the cushions. After nearly 5 hours the cushion is up to killing temperature and I turned the heater off. The air temperature drops rapidly, but the cushion stays over 120°F for another two hours.
The light bulb is just a proof of concept, because it’s entirely too hot: if the fan fails, your luggage ignites. I plan to build a rather subdued heater with a surface temperature around 140°F and a controller that monitors several sensors to ensure the contents reach killing temperatures and stay there long enough.
But that’s a project for another day…
[Update: If you’re arriving from a link, start at the overview to get The Whole Story.]
The Smell of Molten Projects in the Morning 