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.
Who’d’a thunk it?
We spotted this on our regular walk around the block:
The horizontal rails have a latching ramp that’s good enough in most circumstances:
Perhaps those latches released as designed under an overload. The snowplow would have been traveling toward us on that side of the road and pushed the snow against the fence panels hard enough to dislodge the rail latches from their sockets.
I suppose they can zip the fence panels back in place, one by one, without rebuilding the whole affair.
The failed WS2812 pixel remains defunct:
Attach scope probes to its data input and output pins (with the fixture face-down on the bench):
The output no longer comes from the Land of Digital Signals:
I immediately thought the broken bits occupied the first 24 bit times, when the WS2812 controller should be absorbing those bits from the incoming stream. The vertical cursors show the failed bits occupy 54 µs = 40-ish bit times at 800 kHz (or you can count them), so it’s worse than a simple logic failure.
A closer look:
At least for those bits, neither output transistor works well at all. On the other paw, the output shouldn’t even be enabled for the first 24 bits, so there’s that to consider.
Lo and behold, it also fails the Josh Sharpie Test:
You may recall it passed the leak test shortly before I assembled the test array a month ago. Evidently, just few days of operation suffices to wreck the seal, let air / moisture into the package, and kill the controller. Not a problem you’d find during a production-line test (assuming there is such a thing), but it should certain appear during the initial design & production qualification test phase (another assumption).
Weirdly, a day after taking that photo, the controller began working perfectly again and the LEDs look just like they should: there is no explaining that!
A recent OpenSCAD mailing list discussion started with an observation that the dimensions of printed parts were wildly different from the numeric values used in the OpenSCAD program that created the STL. Various folks suggested possible errors, examined the source and STL files to no avail, and were generally baffled.
Finally, a photo conclusively demonstrating the problem arrived:
Note the difference between the digital readout and the analog scale printed on the body.
Turns out it’s his first digital caliper: he simply didn’t realize you must close the jaws and press the ZERO button before making any measurements.
We’ve all been that guy. Right?
FWIW, our Larval Engineer can probably still hear me intoning “Check your zero” every time she picks up a caliper or turns on a multimeter. Perhaps she’ll think fondly of me, some day. [grin]
The Credit Union recommends we practice “Safe Computing” with this helpful advice (clicky for more dots):
The link leading to that page was on their website, but the page is on trabian.com, whoever they are. Should I trust the links on that page to return me to the credit union site or not?
Here’s their definition of “phishing”:
Having just switched to “paperless statements” at the Credit Union, a recent email prompted me to look at my statement. Let’s start by seeing where the email came from:
Huh.
It claims to be from the credit union, but does its actual address (insofar as anything concerning email can be actual) of statement2web.com sound a little phishy to you, too?
Well, let’s look at the full headers, which I can do because, yo, 1337 H4X0R. Here’s a snippet from the bottom of the stack:
Huh.
So the email started from statement2web.com and bankshotted off kbmla.com. Further up, the headers show it rattled through pobox.com and eventually arrived in my inbox. As far as I can tell, it never touched its alleged starting point of hvfcu.org at any point in its journey.
Quick: phish or no phish?
Of course, it’s a perfectly innocent message from the credit union, but it contains every single warning sign we’re supposed to notice in spam or phishing emails, complete with a clicky link!
[heavy sigh]
A few days after epoxying a replacement WS2812 RGB LED into the base of the 21HB5A and, en passant, soldering a 3.5 mm plug-and-jack into the plate lead for EZ removal, the top LED failed.
In this case, it also failed the Josh Sharpie test with bad encapsulation sealing:
Here’s a view from another angle, with a warm-white desk lamp for a bit of color:
Those patterns took a few days to appear and also showed up in some, but not all, of the previous failing LEDs.
Although I have no idea what’s going on, it’s certainly distinctive!
An envelope of RGBW LEDs, allegedly with SK2812 controllers, has arrived from a different eBay supplier, so it’s time for an upgrade.
After months of attempts and (occasionally) spectacular failures, one of the backyard squirrels managed to climb aboard the bird feeder:
The shutter closes when more than two cardinals and a titmouse perch on the wood bar, so the squirrel didn’t get anything. However, back in 2008, one of that critter’s ancestors mastered the trick:
Since then, I’ve raised the feeder about five feet and inverted a big pot over two feet of loose PVC pipe around the pole.
Given the number of squirrel-training videos on Youtube, however, it’s only a matter of time until the critters put all the tricks together!
This big branch must have landed with a mighty thump across the Maloney Road entrance to the Dutchess Rail Trail:
Yeah, some jerk ran a snowmobile up the slope around the tree, leaving a pile of dirt on the ramp. So it goes.
We took an alternate route, I emailed The Right Folks, and (most of) the tree vanished two days later; evidently, the property owner gets to deal with everything to the left of the line of trees.
The Smell of Molten Projects in the Morning 