Archive for April, 2019
Hiatus
We’ll be tackling several long-delayed household projects during the next month. As a consequence, I won’t be doing my usual techie tinkering and will post shop notes only occasionally.
There’s not much to say about scraping, priming, and repainting, other than that it’s an ugly job which must get done!
If only we could train the turkeys to scrape the rail …
The Last Tee
Posted by Ed in Machine Shop, Oddities on 2019-04-26
There’s a good reason this was the last pneumatic tee fitting on the rack:
The center fitting should be a male 1/4 inch NPT connection, but it’s completely un-machined. Alas, I no longer have a 1/4 NPT die in my tool chest, so it’s not an easy fix.
The two female connections are fine, so it must have been one of those rare QC escapes.
Lowe’s marked it down to $0.47 on clearance and I still couldn’t justify buying the thing.
ANENG AN8008 / AN8009 Fuses
Posted by Ed in Electronics Workbench, Oddities on 2019-04-25
The ANENG AN8008 / AN8009 multimeters have 3.6×10 mm ceramic fuses on their inputs:
Based on past experience, at some point over the next year or five, I’ll forget to plug the hot probe back in the voltage hole before measuring a power supply:
Whereupon the fuse will blow.
So, for about five bucks, a bag of 10 A and 0.5 A axial lead fast-blow glass fuses just arrived from halfway around the planet:
They have the right body size and, in this application, fine points concerning current ratings and cartridge composition don’t make much difference. If I actually need one, I’ll snip off the leads, jam it in the holder, and move on.
Xiaomi Dafang Hacks: Hostname for OSD and Filename
Posted by Ed in Photography & Images, Software on 2019-04-24
The config/hostname.conf file (found under /system/sdcard/when the camera is running) file defines the camera’s name:
Cam4That file overrides the contents of the usual etc/hostname.conf file, somewhat to my surprise, which remains the default Ingenic-uc1_1.
The bin/hostname utility returns the hostname:
[root@Cam4 ~]# which hostname
/bin/hostname
[root@Cam4 ~]# hostname
Cam4You can automagically get the hostname in the on-screen display by modifying the OSD formatting variable in config/osd.conf:
OSD="$(/bin/hostname) %Y-%m-%d %H:%M:%S"Which works because the main OSD script sources the config file to set the variable:
It’s also helpful (at least for my purposes) to add the hostname to the image filenames. A one-line tweak in the scripts/detectionOn.sh script does the trick:
snapshot_filename=$(/bin/hostname)_$(date "$snapshot_pattern")Which produces names along these lines:
-rwxr-xr-x 1 ed root 246K Apr 23 2019 Cam4_2019-04-23_17.51.02.jpg*
Having source code makes simple changes like this … simple!
Fiskars Scissors: Preemptive Pivot Tightening
Posted by Ed in Home Ec, Machine Shop on 2019-04-23
A new-to-us Fiskars scissors arrived with a loose pivot of a type I’d never seen before:
The nut fits into the slot in the upper blade, making the nut and screw turn together. Although there’s no torque between the two, the screw had no threadlock and, well, loosening happens.
The pivot parts include a thin washer between the nut and the lower blade to reduce friction between the moving parts:
With a dot of Loctite on the screw, it’s ready for reassembly:
After which, a drop of oil made it sooo smooooth.
That was easy …
Fluorescent Ballast Caps: FAIL
Posted by Ed in Electronics Workbench, Home Ec, Machine Shop on 2019-04-22
After converting another fluorescent shoplight into an LED fixture, I tested its capacitors:
The ESR02 reports one as a 4.8 µF capacitor, the other as a “defective part” with a 4 kΩ resistance. Having a cap fail by turning into a resistor is surprising; I’m more surprised it didn’t simply burn up.
They’re visually indistinguishable, of course.
Dragonfly Eye Re-Re-Repair
Posted by Ed in Machine Shop on 2019-04-21
After not quite seven years, the acrylic caulk holding our garden dragonfly’s eyeballs in place lost its grip. Some cleaning of marbles and scuffing of copper sockets later, two rings of JB Kwik should do the trick:
It’s a family tradition, is all I can say …
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