Archive for December, 2013
This resembles the 32 GB Micro SD card checkout, with the exception that, for some unknown reason, the available space doesn’t match up with the actual space occupied by the file. It also turns out that
rsync deletes the incomplete file, rather than leaving a stub, which makes perfect sense, but was still a bit disappointing after two hours.
I had two identical Sandisk Cruzer Fit Flash Drives, one of which appears here:
Those squares are an inch on a side, so it’s a bit larger than the Micro SD card. Adding a lanyard loop on the plastic cap or a string between cap and drive seems like a great idea, because that little thing is certain to get lost.
The snippets here represent a compendium of Things Done that happened over the course of two days; I didn’t save all the logs. The process started with the same 32 GB file of entropy I used for the Micro SD card:
df -B1 /mnt/part2 Filesystem 1B-blocks Used Available Use% Mounted on /dev/sdc1 31512350720 180424704 31331926016 1% /mnt/part2 ----------------------- time rsync --progress /mnt/part/Testdata/Testdata.bin /mnt/part2 Testdata.bin 31298191360 99% 14.18kB/s 0:39:38 rsync: writefd_unbuffered failed to write 4 bytes to socket [sender]: Broken pipe (32) rsync: write failed on "/mnt/part2/Testdata.bin": No space left on device (28) rsync error: error in file IO (code 11) at receiver.c(322) [receiver=3.0.9] rsync: connection unexpectedly closed (28 bytes received so far) [sender] rsync error: error in rsync protocol data stream (code 12) at io.c(605) [sender=3.0.9] real 126m20.505s user 3m6.393s sys 2m17.492s ----------------------- time dd bs=8K count=20000000 if=/mnt/part/Testdata/Testdata.bin of=/mnt/part2/Test1.bin dd: writing ‘/mnt/part2/Test1.bin’: No space left on device 3820963+0 records in 3820962+0 records out 31301320704 bytes (31 GB) copied, 7455.97 s, 4.2 MB/s real 124m15.970s user 0m1.607s sys 1m17.546s ----------------------- truncate -s 31301320704 /mnt/part/Testdata/Testdata.bin ----------------------- ll /mnt/part/Testdata/Testdata.bin -rw-r--r-- 1 ed ed 31301320704 Dec 24 18:13 /mnt/part/Testdata/Testdata.bin ----------------------- time diff /mnt/part/Testdata/Testdata.bin /mnt/part3/Test1.bin real 26m37.081s user 0m4.400s sys 0m52.723s
Notice that the write speed runs around 4 MB/s, which is a lot slower than you might expect from a USB 2.0 device; as with a hard drive, the interface doesn’t limit the throughput! The read speed, on the other paw, trots along at about 20 MB/s.
One of these will go to Mary’s folks as an online daily backup device; their PC will soon run a version of the rsnapshot scripts that back up our basement file server. It’s not off-site backup and it’s not proof against catastrophic hardware failure, but it should be good enough.
Most of the things I design don’t have moving parts, so I printed emmitt’s Gear Bearing as a fondletoy:
Setting the clearance to 0.5 produced a free fit with absolutely no cleanup or run-in required; the center hole is a sliding fit for a 6 mm hex wrench.
I should do another one with knurling around the outside…
The picture has strongly desaturated reds, which reveals the top surface a bit more clearly.
Mary’s compadres sometimes send her pictures of garden vegetables and quilting projects. Those pictures usually pass through Microsoft Outlook (or its ilk) and emerge in
winmail.dat files that aren’t particularly useful in a Linux context. That page gives a good overview of the problem and how to resolve it; I’m just documenting the process here, so I can find it again.
Start by installing both
convmv. I think the latter isn’t needed in our situation, because most folks use flat ASCII file names that come through just fine.
Save the attachment in, say
/tmp and unleash
tnef on it:
cd /tmp tnef --file=winmail.dat
That unpacks all the attachments into
/tmp, where one may have one’s way with them.
It’s not worth my effort to bolt that into the email programs and then maintain that mess across updates, so we’ll do it by hand as needed.
Microsoft certainly had a good reason for inventing Yet Another Encapsulation Format, although I wonder why good old ZIP wouldn’t have worked nearly as well…
Spotted this in a greenhouse:
Just like fire extinguishers and bike helmets, you never know when you’ll need to use this thing in a hurry… then it’s too late to clean out all the crap that accumulates on any flat (or concave) spot.
Not that I’m completely innocent, of course.
The DSC-H5 had been outdoors for a few hours, hiking with us at 25 °F, so the lens fogged instantly when we walked through the greenhouse door.
The new-to-me Optiplex 980 has a tool-free clamp securing the PCI card brackets to the chassis, with a nice plastic dress cover that really finishes off that side of the case. Alas, it’s secured by five small heat-staked plastic pegs that I managed to shear off as part of a finger fumble that you’ll recognize when it happens to you and which I need not further discuss:
So I drilled two slightly undersized holes for the tiniest screws in the Little Box o’ Tiny Screws:
The two end plates sticking up are the only square parts of the cover, so that thing is actually clamped by the right-side plate and sheer will power. I ran the drill down 3 mm from the top of the post at the slowest manual jog speed from the Joggy Thing and I did not break through the top and did not hit that lathe bit under the cover.
The screw threads and a dab of epoxy hold them in place:
I’d like to say the finished repair looked like this:
But, alas, the eagle-eyed reader will note that the screws are gone, replaced by two dabs of clear acrylic caulk; those faint threads and epoxy were no match for the snap of that latching lever and the slight distortion caused by the spring fingers applying force to the brackets.
Ah, well, it’s close enough…
Measure with a micrometer. Mark with chalk. Cut with an axe.
While pondering the problem of having the Sherline’s Z-axis anti-backlash nut unscrew at the top of its travel, I excavated the gauge block set and measured the gap between it and the bearing preload nut:
Turns out that it’s 0.1340 inches, determined by bracketing the sliver above that 0.1300 block with feeler gauges. I don’t believe that last zero, either, as the Basement Shop was about 10 °F below the block’s 68 °F calibration temperature. [grin]
The actual size of that gap makes absolutely no difference whatsoever, but fooling around with the gauge blocks gave me an excuse to renew my acquaintance with them and, en passant, massage some oil over their long-neglected bodies:
I used La Perle Clock Oil, which isn’t Official Gauge Block Oil, but doesn’t go bad on the shelf. Verily, this bottle may be the last of its kind, as it’s no longer available from any of the usual sources; it appears I bought it back in 2000.
The blocks are in good shape, probably because they don’t often see the light. FWIW, I have experimentally determined that my body oil doesn’t etch fingerprints into steel.
The block set, which is similar to a current box o’ blocks from Enco, claims “Workshop Grade”, but the ±0.00050 inch = 1.27 μm tolerance shown in the top row of the labels is much worse than even grade B’s sub-micron tolerance. That newer box claims “Economy” accuracy with the same spec, so I suppose somebody kvetched about mis-using the terms.
Ah, well, they’re far better than any measurements I’ve needed in a while and entirely suitable for verifying my other instruments.