Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
Category: Science
If you measure something often enough, it becomes science
A day later, most of the boxes were in the 10%RH to 15%RH range, with the filament spools slowly releasing their stored moisture. The PETG Orange meter jumps between 10% and 27%, with the latter more believeable.
Changing the desiccant every month, without thinking too hard, may be the simplest path to dry filament storage.
Although “chipboard” is also known as “beer mat”, it’s not intended for long-term use under sweaty mugs. After a few weeks of daily use, this is obviously out of spec:
Printed Fragment Coaster – moisture damage
The aforementioned sweaty mug lifted part of a fragment off the coaster:
Printed Fragment Coaster – delamination
The chipboard is Quickboard from Makerstock, which is basically recycled-fiber chipboard with the advantage of being through-dyed in cheerful colors. It’s described as “2 mm-thick, three-layered board” and it looks like the core delaminated from the bottom layer.
Seeing as how it’s near the end of Sweaty Mug season, I smeared Elmer’s Glue Stick PVA adhesive over the fragment, stuck it back in place, and declared victory.
Going back to the original GIMP tracing (storage being cheap, never delete anything), I missed a pixel:
Printed Fragment Set C – GIMP selection – errant pixel
Surely you can see it, particularly because you know exactly where it is. Right?
The (degenerate) path around that pixel becomes a tiny vector in LightBurn:
Printed Fragment Coaster – Set C – orphan vector
It’s easier to see there. Right?
Whereupon LightBurn dutifully punched a pinhole through the chipboard, because that’s what I asked it to do. It also punched that pinhole into the metallized paper reflector under the smashed glass fragment, but I didn’t notice it then, either.
Shrinking the GIMP selection by one pixel width, then growing it by one pixel would eliminate single-pixel selections: just another item on the to-do list while tracing fragments.
Although I’d sealed the cracks around the front door after the previous Yellowjacket encounter, a cloud of Yellowjackets revealed their queen had set up housekeeping between two plants in front of our house. I donned my beekeeper suit, sprayed the obvious entrances with wasp killer, then repeated the dose over the next several days until, as Khruschev apparently didn’t say, the survivors envied the dead.
The nest was about a foot in diameter, with the top slightly above ground level and bonded into the leaf / mulch layer:
Yellowjacket wasp nest – top overview
It had two active layers below the top (positioned upside-down here):
Yellowjacket wasp nest – side view
The bottom view gives a better idea of its extent:
Yellowjacket wasp nest – bottom overview
I know nothing of wasp nest building, but if they’re similar to honeybees, then the much larger cells in the disk were intended to raise overwintering queens to start new nests next spring:
Yellowjacket wasp nest – new cell structure
The longer capped cells sticking out beyond the others may raise the few drones required to mate with queens from other nests:
Yellowjacket wasp nest – capped cells
That’s a fly over on the left; the scavengers wasted no time getting in there for the (perhaps still poisonous) goodies.
My wasp identification skillz are weak, but this looks like an American Yellowjacket:
You’ll note the sensor’s signal wire is blue, not white, but red = 5 VDC and black = common on both sides of the splice. This is not to be sniffed at.
With the disk magnet (supplied with the sensors) oriented edgewise to the sensor, so the magnetic field is largely cancelled, the maximum separation allowing the sensor to remain On is about 7 mm:
Tour Easy LED brake sensor – edge – max ON
The minimum distance allowing it to be Off is 8 mm:
Tour Easy LED brake sensor – edge – min OFF
Orienting the disk face-on to the sensor increases the distances, because the magnetic field is not cancelled out in that direction. Similarly, positioning the magnet either above or below the plane of the sensor changes the results.
The maximum On distance is now 20 mm:
Tour Easy LED brake sensor – side – max ON
The minimum Off distance is 22 mm:
Tour Easy LED brake sensor – side – min OFF
The other magnet has a similar field strength and the other sensor responds at nearly the same distances, so they’re reasonably matched.
The LEDs are, however, not well matched: one sensor is much brighter than the other. I only have one connector, so I cannot show both in the same picture. These pictures have the same exposure (1/120 s and f/1.7), with the top sensor appearing in the previous pictures:
E-bike Brake Sensors – LED Brightness comparison
The red LEDs show a similar difference. I’m certain this doesn’t rise to the level of a warranty claim, because, hey, maybe the brighter one should be dimmer.
