Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
This from a restroom near the new high school auditorium, rebuilt at vast expense over the course of several years. You’d think for all the big bucks, somebody would remember that trim plates require a flat surface.
It’s not like I’ve never forgotten a detail in any of my designs. In this case, though, several different people surely noticed this situation and none of them were sufficiently empowered to fix the problem.
I’ve got a ten cent bet with myself that this will never get repaired. I’ll likely never know, though, as my Shop Assistant graduates this year.
Found this on the hand-cranked reel that deployed an outdoor table umbrella in DC…
Table Umbrella Cable Winch
I think you’re not supposed to:
Stand under something held by this cable
Use it for motive power (?)
Hang from it
I think they’re violating the first warning, as the cable holds the umbrella open over your head. On the other paw, it’s not a monster dead weight, so maybe it’s OK.
I’m not sure whether all unit prices must be converted to “per 100 count” or not, but it really doesn’t work out well for CFL bulbs (clicky for more dots):
CFL 2-bulb pack
That’s $549.50 per 100 bulbs, if you can’t make it out.
On the shelf below, however, a single-bulb pack priced out to $979 per 100 count, so the 2-pack is definitely a better deal!
The NYS DOT recently spiffed up Raymond Avenue in Arlington, installing three small diameter rotary intersections and rows of street lights with lenses cunningly contrived to glare directly in your eyes. Why installing black, non-reflectorized bollards two feet away from the travel lane at each crosswalk seemed like a good idea escapes me, too.
Anyhow, it seems one of those streetlights was a bit too close to the corner. The ruts across the top of the picture came from a truck that evidently clipped the pole and neatly fractured the entire aluminum (?) base casting without bending anything else.
Fractured street lamp post
Further south, this wall in Wappingers Falls shows why flat-roof building aren’t such a great idea in snow country:
Ice flow across wall
That isn’t a new problem, by the way. Last year it looked like this:
In the Mysteriously Missing Label category, we find three similar products with only one shelf label. Which one is the better deal?
Caffeine unit pricing
You might think it’d be the Wal-Mart Equate house brand. In order to find out, you’d have to haul all three offerings down the aisle and around the corner to the price scanner, which would reveal it’s the one on the far left, by a considerable margin. Oddly, that one says “Double Strength” even though it has the same 200 mg dose as the others.
In the Bizarre Units category, we have two very similar products with completely different unit-price units of measure. Seeing as how a “fluid ounce” is a unit of volume and a “pound” is a unit of weight (or, for the pedantic, force), even the dimensions aren’t compatible. Clicky for bigger pictures.
Vanilla unit pricing – 2 oz
And, just to show that wasn’t a one-off mistake that could happen to anyone, the smaller size containers continue the theme.
Vanilla unit pricing – 1 oz
Given that nothing in a Wal-Mart store happens by accident, someone was directed to remove two of those three labels and another someone deliberately chose incompatible units.
Of course, anyone I’ve ever asked has no idea why that would happen…
Having built cartridge heater mounting blocks, I autopsied the two aluminum-case power resistors I’d been using on the MK5 Thermal Core. They weren’t dead yet, but I have some spares in case the cartridge heaters don’t work out as expected.
First observation: the blue-tinted thermal compound I’d put under the resistors turned white! It has a 200 °C maximum rating, so it’s been cooked well beyond any reasonable limit. On the other paw, it was still soft and didn’t have any air bubbles; the resistors were pretty firmly glued in place.
Based on those thermal measurements, I had replaced the original parallel-connected 5 Ω resistors with series-connected 2 Ω resistors, thus reducing the power dissipation in each resistor from 28.8 W to 18 W. While that’s still far beyond the specification, every little bit of reduction helps.
In round numbers, the resistors ran at 50-75% duty cycle to maintain Thermal Core temperatures in the 200-230 °C range. I guesstimate I had 10-15 power-on hours on the resistors, but that may be a lowball estimate: time passes quickly when you’re having fun.
Anyhow, I slipped a brass tube around one resistor terminal, braced the other end on the drill press vise, and pressed the cores out.
Resistor elements
The top core literally fell out without any urging, which means that it had shrunk and separated from the housing. That means the resistor was well on its way to failing: a loose core gets hotter and deteriorates faster.
The bottom core was still firmly attached and disintegrated as I forced it out, which means it was in good condition. Paradoxically, the crumbled resistor core in the picture came from the resistor in the best shape.
Given that I ran these resistors at 63% of the original power level, the fact that one was well on its way to heat death after only (at most) a few tens of hours suggests that you shouldn’t expect much life from the stock MK5 resistors. If you haven’t already done so, electrically isolate the thermocouple bead from the Thermal Core to protect the Extruder Controller.
I’m unwilling to sacrifice a new resistor to see if that discoloration is normal, but I suspect it’s not. The ends should be the coolest part of the resistor, which means the middle is discolored, but that picture suggests the opposite, so I really don’t know.
I’d hoped the ID of the resistor bodies would match the OD of the cartridge heaters. That didn’t work out: 0.275 vs 0.250. They’re also a bit too short. If the match was closer, I could see slipping a shim in there, but having two air gaps around the heater just doesn’t make any sense at all.
The Smell of Molten Projects in the Morning 