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.
A moth came within arm’s reach during a ride along the Dutchess County Rail Trail:
Squinting at some earlier frames that show only a tiny moving dot, the moth disappears every five frames: one wingbeat requires either 5/60 or 10/60 s = 12 or 6 strokes/second.
We continued our respective missions without incident…
The moth came much closer to the camera than it looks. I should calibrate the images with known objects at known distances, but that seems like a lot of work.
Back in high school, I designed and built a slide rule exposure calculator to improve my macro photographs:
The base consists of three layers of thin cardboard glued together with Elmer’s Glue. The three slides have three layers of thinner white cardboard glued together, with offsets forming tongue-and-groove interlocks, topped with yellow paper for that true slide rule look:
Judging from the seams, I covered the hand-drawn scales with “invisible” matte-surface Scotch Tape. Worked well, if you ask me, and still looks pretty good:
The reverse side carries instructions under a layer of packing tape (which hasn’t survived the test of time nearly as well), for anyone needing help:
A closer look at the instructions:
The slides still move, albeit stiffly, and it might be usable.
I vaguely recall extension tubes on an early SLR, but memory fades after that. Getting the exposure settings close to the right value evidently posed something of a challenge and, given the cost of 35 mm film + development, it made sense to be careful.
Fortunately, even today’s low-end cameras make macro photography, at least for my simple needs, easy enough, with the camera handling the exposure calculations all by itself:
I’m definitely not on the level of a professional insect photographer!
Randy’s observation to Amy in Neal Stephenson’s Cryptonomicon comes to mind:
“… One of the most frightening things about your true nerd, for many people, is not that he’s socially inept — everybody’s been there — but rather his complete lack of embarrassment about it.”
“Which is kind of pathetic.”
“It was pathetic when they were in high school,” Randy says. “Now it’s something else. Something very different from pathetic.”
“What, then?”
“I don’t know. There is no word for it. You’ll see.”
The converted OttLite hit the floor again and, this time, the shell around the lamp popped free. Given that I didn’t know how to take it apart before, this is new news.
There’s a small snap latch inside the bottom / inner surface:
And two guide notches + latch nubs inside the top / outer surface:
So, if you had to get it apart by hand, a spudger-like tool applied to the bottom / inside of the shell and a bit of tugging should do the trick.
It snapped back together without incident, but I really must figure out a bigger base for the damn thing.
Mad Phil gave me his Brother PT-1090 labeler, which I’ve been using rather often of late. The white tape cartridge (the TZ flavor) ran out, giving me the opportunity to pry it apart:
Surprisingly, a few small pins molded into the cover, plus a few obvious latches, hold it together without a trace of glue or thermal welding.
A detail of the little factory that assembles the label from several parts:
Colored paper tape unwinds from the lower right and the top plastic layer from the lower left. Tape with thermal dye unspools from the upper left, the printhead (in the printer) heat-transfers pixels to the plastic tape in the opening right of center along the top, and the roller at the top right joins the just-printed plastic layer to the slightly sticky front surface of the paper tape. The used imaging tape respools in the gray cylinder near the middle.
For those concerned with privacy, that gray spool of used imaging tape contains everything you’ve printed in order:
I thought the thermal dye was part of the transparent tape cover layer, but in retrospect that doesn’t make sense: the printed tape would turn black in hot environments like, say, your car. So the printer must transfer the dye from a separate tape.
The knockoff “ESD” tape cartridges from Amazon seem to have a slightly different tape path, probably to work around Brother’s patents. I’ll pry one of those apart in due course.
For obscure reasons, the Silly Season brought Sanders, Trump, and Clinton fille to the City of Poughkeepsie within the span of eight days. We know enough to stay far away from such events, but one of the contestants came to us!
A siren heralded flashing lights off to the left, coming up the hill from the bridge over the Mighty Wappingers Creek:
The police car jammed to a stop in the middle of the Red Oaks Mill intersection, directly in front of the cars (and bikes) that had just begun moving after the light turned green:
During the next minute, the officer managed to clear most of the traffic from the left-turn storage lanes perpendicular to us, after which two motorcycle officers led the procession:
Two ordinary SUVs with flashing light bars followed:
Two stretched SUVs with side window and marker flashers:
One blatantly inconspicuous black sedan running dark:
Two black patrol cars and a white patrol car, all with flashing lights:
The officer jumped into his car and rejoined the procession at the end:
According to my back-of-the-envelope, the motorcade moved through the intersection at a steady 20 mph.
Given where all the folks who merit such an escort were supposed to be at the time, I don’t know why they brought The Personage through the Red Oaks Mill intersection in that direction; the City of Poughkeepsie is to our rear, due north of Red Oaks Mill. Perhaps they’re following a randomly chosen route to confuse the unprepared, even though it’s longer and requires more traffic control?
Rumors from a Reliable Source indicate that not all trains travel on steel rails.
I suppose you eventually get used to having a couple of quiet people standing in every room with you.
One benefit of the inevitable news coverage: a few more people now know how to pronounce “Poughkeepsie”.
Just because I hadn’t done so for quite a while, I rode Grand Avenue from Beechwood north to the rail trail. The rotted asphalt at the Westbound Arterial (a.k.a. Maple St, at that point) intersection makes it easy to spot the quadrupole sensor loop:
After half a minute, with no traffic pulling up behind me, I eased the bike over the central wire:
Which is exactly as awkward as it seems:
Much to my surprise, the sensor tripped:
That’s about 50 s from the time I rolled over the first of the two sensor loops, which is fast enough for me. It’s unusual to find a sensor loop that detects a bike, though.
A bit over 6 s seconds later, I’ve cleared the intersection:
The rear camera shows that the light remains green:
And it stays green:
About 11 s after turning green, a car approaches the sensor loop:
I think that reset the signal timing, so that light remained green for nearly 23 s:
It turned red after 26 s:
As nearly as I can tell, the minimum green time for this intersection is 12 s.
So life is good: the sensor loop detects a bicycle and the signal remains green for long enough to a bike to clear the intersection. If only all intersections worked that way!
Compare that with the minimum 7 s for the Burnett Blvd intersection and you (well, I) wonder why crossing six lanes requires 5 s less than crossing three lanes. Perhaps different standards apply to this single-direction cross-traffic flow that make it much more difficult than Burnett’s bidirectional cross traffic?
Mary wanted a rigid cap for a Clover seam ripper that came with a small plastic sheath, so I called one from the vasty digital deep:
The solid model looks about like you’d expect, with a brim around the bottom to paste it on the platform:
I added a slightly tapered entry to work around the usual tolerance problems:
The taper comes from a hull wrapped around eight small spheres:
That’s surprisingly easy to accomplish, at least after you get used to this sort of thing:
hull() { // entry taper
for (i=[-1,1] , j=[-1,1])
translate([i*(HandleEntry[0]/2 - StemRadius),j*(HandleEntry[1]/2 - StemRadius),0])
sphere(r=StemRadius,$fn=4*4);
for (i=[-1,1] , j=[-1,1])
translate([i*(HandleStem[0]/2 - StemRadius),j*(HandleStem[1]/2 - StemRadius),HandleEntry[2] - StemRadius])
sphere(r=StemRadius,$fn=4*4);
}
The side walls are two threads thick and, at least in PETG, entirely too rigid to slide on easily. I think a single-thread wall with a narrow ridge would provide more spring; if this one gets too annoying, I’ll try that.
The OpenSCAD source code as a GitHub gist:
| // Clover seam ripper cap | |
| // Ed Nisley KE4ZNU – April 2016 | |
| //- Extrusion parameters – must match reality! | |
| // Build with a 5 mm brim to keep it glued to the platform | |
| ThreadThick = 0.25; | |
| ThreadWidth = 0.40; | |
| Protrusion = 0.1; | |
| //—— | |
| // Dimensions | |
| StemRadius = 0.50; // corner radius | |
| HandleStem = [6.1, 7.1, 9.0]; | |
| HandleEntry = HandleStem + [1.0,1.0,-4.0]; // Z is -(straight part of stem) | |
| Cap = [8.5,11.0,45.0]; // XY exterior, Z interior | |
| //———————- | |
| //- Build it | |
| difference() { | |
| union() { | |
| translate([0,0,Cap[2]/2]) // main body column | |
| cube(Cap,center=true); | |
| translate([-Cap[0]/2,0,Cap[2]]) // rounded cap | |
| rotate([0,90,0]) | |
| cylinder(d=Cap[1],h=Cap[0],$fn=8*4); | |
| translate([Cap[0]/2 – Protrusion,0,(Cap[2] + Cap[1]/2)/2]) // text | |
| rotate([0,90,0]) | |
| linear_extrude(height=ThreadWidth,convexity=10) | |
| text("Mary Nisley",halign="center",valign="center",size=0.5*Cap[1],font="Arial"); | |
| } | |
| hull() // stem + blade clearance | |
| for (i=[-1,1] , j=[-1,1]) | |
| translate([i*(HandleStem[0]/2 – StemRadius),j*(HandleStem[1]/2 – StemRadius),-Protrusion]) | |
| cylinder(r=StemRadius,h=Cap[2] + Protrusion,$fn=4*4); | |
| hull() { // entry taper | |
| for (i=[-1,1] , j=[-1,1]) | |
| translate([i*(HandleEntry[0]/2 – StemRadius),j*(HandleEntry[1]/2 – StemRadius),0]) | |
| sphere(r=StemRadius,$fn=4*4); | |
| for (i=[-1,1] , j=[-1,1]) | |
| translate([i*(HandleStem[0]/2 – StemRadius),j*(HandleStem[1]/2 – StemRadius),HandleEntry[2] – StemRadius]) | |
| sphere(r=StemRadius,$fn=4*4); | |
| } | |
| } |
The Smell of Molten Projects in the Morning 