Archive for August, 2017
Sharing the Road on Raymond: Friend or Foe?
Posted by Ed in Photography & Images, Recumbent Bicycling on 2017-08-31
A silver Honda Accord Civic (NY HLS-3678) passed me on Raymond, just before the Vassar Main Gate roundabout, with about as much clearance as one might expect:
I noodled along Raymond at 18 mph and the car pulled ahead at the usual 30 to 40 mph. Just after the College Avenue roundabout, the car pulled off to the right, as if to park, but continued rolling slowly and I gave it plenty of clearance:
The car immediately pulled out into the lane, directly in front of the Escalade that’s been following me at a courteous distance since the Main Gate roundabout, and pulled up close behind me, which immediately put me at DEFCON 3. Basically, drivers get exactly one bite at my apple; anyone who deliberately passes me a second time is likely up to no good.
As always, I signal and take the lane going into the Collegeview Avenue roundabout, still at 18-ish mph, whereupon the driver lays on the horn rather heavily. Apparently, he intended to accelerate past me into the roundabout, but I got in the way:
I’m now cranking 20 mph. A block later, the car passes me, rather closely this time:
Maybe this is a friendly wave, but the horn thing suggests otherwise and, in any event, it’s hard to tell in real time running:
At this point, I presume he’s gesturing me to GTFO the road:
And we part company:
Raymond Avenue would be a lot more bicycle-friendly without some of the drivers …
Sharp EL-531W vs. EL-531X Calculators
Posted by Ed in Electronics Workbench, Machine Shop, Science on 2017-08-30
(Typo in the permalink: should be W vs. X. Fixing it will break all the auto-linkies. Hate it when that happens.)
When our lass first began using calculators, I put a pair of Sharp EL-531W calculators in harm’s way around the shop, where they still reside. The new EL-531X seems to have an identical key layout and internal logic (*), as well as the same under-ten-buck price, but I don’t like it nearly as much:
It’s maybe 10 mm wider and doesn’t fit readily in my hand. I’m sure the rounded-rectangle stylin’ mimics a phone, but the cheapnified keys look ugly (particularly the ones around the arrow keys at the top) and don’t feel nearly as good.
The new one fills a gap next to the lathe, where it should collect plenty of swarf.
(*) Including engineering notation with multiple-of-three exponents, which I regard as vital.
Multimeter Banana Plugs
Posted by Ed in Electronics Workbench, Machine Shop on 2017-08-29
The second banana plug on one of my multimeters failed, so I finally got around to replacing them with a dual plug from the Drawer o’ Banana Stuff:
The bulky test leads don’t quite fit through the convenient retaining ring, so the zip tie holds ’em in place.
A setscrew at the base of each banana jack tunnel crunches the test lead wire against the plug base, but, alone among the collection, this plug had one missing screw. Rather than toss it away (or, worse, back in the Drawer), I decided to Solve The Problem once and for ever:
That’s an ordinary M3 screw from the Drawer o’ Random M3 Stuff with its head hacksawed off, a slot crudely hacksawed slightly off-center into the end, then lightly filed to hide the worst damage. With a bit of luck, nobody will ever notice it …
Knockoff RAMPS 1.4 Printer Controller Hardware Kit
Posted by Ed in Electronics Workbench, Machine Shop on 2017-08-28
For 36 bucks delivered halfway around the planet, you can get a remarkable pile of gadgetry:
With a bit of persuasion, it can become a 3D printer controller based on a RepRap RAMPS 1.4 shield or serve as a generic stepper / servo motor driver with three honkin’ MOSFET power switches, two thermistor inputs, a variety of I/O bits from the Arduino Mega PCB, and a monochrome LCD with a knob.
The persuasion includes un-bending various header pins:
Correcting bowlegged pin strips:
And clipping offending pins:
The interference between the bottom of the RAMPS power connector pin and the top of the Arduino Mega coaxial power jack seems baked right into the original PCB layout, which is puzzling. If you don’t trim the pins, this is as close as the boards will get:
Well, of course, you could just jam all those headers together and bend the RAMPS PCB.
The bent pin near the Reset button connects to the PS_ON
output used to enable ATX-style power supplies. You connect the supply’s 5V_SBY
always-on output to the VCC
pin, which powers the Mega and most of the logic, but not the stepper motor outputs or the heaters.
To make that work, remove D1 from the board where it’s snuggled along the header strip:
D2, next to the fuse near the bottom of the picture, provides reverse-polarity protection for the RAMPS board.
The servo motor power comes from the 5V
pin. If you don’t need the PS_ON
output and 5V_SBY
input, then jumper the VCC
and 5V
pins together. Otherwise, you could solder-blob those pins on the bottom of the board, which means the servos are always powered.
Configuring the latest 1.1.x version of Marlin should be straightforward …
Cocooning
Each of the three Mystery Caterpillars wandered around the aquarium for a few minutes, found a spot surrounded by leaves, and tucked themselves into their cocoons.
The smallest one went first and probably got the best site:
The medium one:
The largest caterpillar munched the leaf around the new cocoon and removed some of the silk (?) wrapper. It looks like the caterpillar’s fur falls off and becomes insulation inside the wrapper.
The large one with mostly black fur managed to bind two leaves together:
The Monarch remained calm, well above the scramble:
The caterpillar’s skin (or whatever it is) remained loosely attached to the outside.
All of which puts me in mind of Della Lu:
FINAL WARNING!
PROJECTION WILL SELF-ENCLOSE.
CONTINUE?
I wonder what they’re thinking after they type Y E S
…
Praying Mantis
It’s the season for large insects, but this Praying Mantis came as a surprise:
Mary spotted it on the outside of the window screen in the front bathroom. We watched it for ten minutes as it strolled around the screen, all the while keeping at least one compound eye aimed at us.
If humans were half as tall, those things would be terrifying!
Google Pixel vs. Clip-on Lenses
Posted by Ed in Machine Shop, Photography & Images on 2017-08-25
The clip-on lenses for the (fancy) camera in my soon-to-be-obsolete Google Pixel XL don’t fit well on the case I added to improve its griptivity:
The upper half of the clip rests on the rim of the case around the bezel, with only the end of the foam pad against the glass:
That’s pretty much the only stable position.
Sticking a disk of stair-tread rubber on the foam adds just enough thickness to match the rim:
The lenses came with two clips, so I left one unmodified to fit the Pixel without the case:
Not that that happens very often, but …
The lenses are about as good as you’d expect for ten bucks from Amazon. Stacking the 0.67 “wide angle” lens on the camera enlarges the field-of-view by a third with closer focusing at maximum zoom, so the minimum FOV drops from 2 inches down to 1 inch at a reasonable distance. The 10x “macro” lens is basically useless, with a focus distance well within the Pixel’s shadow under any normal lighting; if I were that sort of guy, I’d conjure a small LED ring powered from the USB-C port.
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