Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
Spotted this one in a rest stop along I-84. I suppose it’s perfectly safe, but those anchoring hooks really don’t inspire much confidence, even if the only way you could jounce that crane sideways would involve flipping the flatbed. Right?
Yes, it was hanging over the other side just as far.
Come to think of it, the tractor that towed this assembly wasn’t present. Perhaps someone discovered / was informed it really isn’t a Good Idea / legal to haul an excavator at 65 mph in this configuration?
Saw this at breakfast early one morning in DC on our April vacation:
Panera Bread alarm panel – bad clock
Here’s the key part, amped up for readability:
Panera Bread alarm panel – clock detail
I’m sure the manager’s three-ring binder has a whole section about the alarm system, its care & feeding, and the importance thereof. I’d guess there’s a dead battery in there somewhere and a power failure in the recent past.
This ooops obviously doesn’t matter, right up to the point where they have a break-in and the alarm system timestamps the event incorrectly.
The camera peered through a pair of window panes across the entranceway, as I didn’t want to get too conspicuous… we were, after all, in DC.
We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness. Prudence, indeed, will dictate that Governments long established should not be changed for light and transient causes; and accordingly all experience hath shewn, that mankind are more disposed to suffer, while evils are sufferable, than to right themselves by abolishing the forms to which they are accustomed. But when a long train of abuses and usurpations, pursuing invariably the same Object evinces a design to reduce them under absolute Despotism, it is their right, it is their duty, to throw off such Government, and to provide new Guards for their future security.
We read the original document in DC a few months ago, while doing the touristy thing. These days, that means submitting to a search on the way into each museum; Mary lost her forgotten-in-the-bottom-of-her-purse Swiss Army Knife to the Smithsonian guards.
We left town feeling that something has gone badly wrong in the last decade or so.
That comment prompted me to rummage around for one of my favorite photos: a much younger version of my Shop Assistant helping us shred leaves in the front yard.
Shop Assistant in Autumn leaf pile
She thinks it’s entirely right & proper to:
don safety goggles while doing anything even remotely eye-unsafe
wear a dust mask to mow the lawn
jam 30 dB foam plugs into her ears during thrash metal concerts
As the scrawled notation says: printed at 50 mm/s with 100 mm/s moves. The only cleanup: remove the scaffolding and slice off the Reversal zittage.
If the truth be known, that was actually the third knot. The first suffered a spectacular failure: one corner of the filament spool snagged on the wall behind the printer and jammed the filament:
Large Knot – failed
The filament drive pulled all the slack out of the bundle, broke off three of the six internal guide posts (admittedly, they’re just hot-melt glued in place), and dragged a nasty kink halfway down the feeder tube. Obviously the stepper was shedding steps during that whole process, but it came rather close to doing the Ouroboros thing.
While that went down, I was puttering around in the far reaches of the Basement Laboratory, attempting to clean up a bit of the clutter, and checking in on the printer every now and again. Seemed like a good idea at the time, is all I can say.
Perhaps the Lords of Cosmic Jest simply decided this was an appropriate object to mess with. The vertices of the hexagonal filament spool stick out perhaps 10 mm from the printer’s backside and every one has cleared the wall on countless previous rotations. I moved the entire affair a bit further from the wall and maybe it’ll be all good from now on.
The supply voltage for that picture came from a bench supply and, having confirmed that the initial slope of the current waveform matched the voltage, I twiddled the knob while watching the slope change.
As expected, lower voltage = lower slope and higher voltage = higher slope. That worked fine, right up until a firecracker popped about a foot in front of my face, launched a missile over my left shoulder, and filled the Basement Laboratory with the pungent smell of electrical death.
Detonated electrolytic cap
While wiring up a hairball test circuit for that Pololu driver, I’d put a pair of electrolytic caps on the +5 and +12 V supply lines, seeing as how solderless breadboards aren’t all that great for power distribution. The brown fur growing just to the upper right of the heatsink is what’s left of a 16 V cap that had 25 V applied for a few seconds: I’d wired in the bench supply in place of the breadboard’s fixed +12 V output and forgot all about the caps.
The cap body departed for the far reaches of the Basement Laboratory, leaving behind shredded cardboard and unrolled plastic strips. I’m sure it’ll turn up some day.
Nothing else took any damage, but for a few minutes I thought I’d killed Eks’ AM503 current probe, which pokes in from the lower right.
The black lump just above the probe is an ordinary AC current transformer that didn’t work well at all: the 1/rev frequency was just too low.
If you don’t always wear glasses at the workbench, start now.
The Smell of Molten Projects in the Morning 