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Archive for May, 2010

Monthly Aphorism: On Cleaning

  • If you have to move it to clean behind it, don’t move it.

Dad knew that most dirt wasn’t particularly harmful, so he didn’t worry about it. If you had occasion to move something for whatever reason, that was the appropriate time to break out the vacuum cleaner (or shovel) and deal with whatever you find, but there was never a reason to go looking for trouble.

Of course, I feel the same way. Equally of course, this drives my esteemed wife crazy…

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New Tires for the Van: Overtightened Lug Nuts

The shop spec says the lug nut torque shall be 104 newton·meter or an equally odd 77 lb·ft. Let’s not get into quibbles about the differences between lb·ft and ft·lb here, OK?

Anyhow, based on the wildly differing and grossly excessive tire pressures left by the guys who installed the new tires, I figured the lug nuts would be over-torqued… as, indeed, they were. My bending-beam torque wrench goes up to 140 n·m and didn’t even come close to breaking those puppies loose.

So I deployed a manly breaker bar and applied most of my weight to the far end. A back of the envelope guesstimate says they were well over 200 n·m, with a few grunt outliers.

Yes, the breakaway torque can be higher than the tightening torque, but they were far beyond even that level.

Lubed the threads, tightened to spec, and it’s all good. I’ll check them next week just to be sure, but sheesh if we had to fix a flat on the road, it would have gotten ugly.

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Do You Feel Lucky Today?

Drugs by Nostrum

Drugs by Nostrum

Just got a new shipment of dope from our usual mail-order med supplier. The new dope comes in a livid red capsule, a disconcerting change from the previous green.

So, being an educated and somewhat wary consumer, I check the label to see what’s new. It seems my supplier is dealing from a new manufacturer!

Hitherto, I’d only encountered the word nostrum in phrases preceded by words like quack. The dictionary definition, at least for some values of dictionary, seems to back that up:

Noun

Nevertheless, Nostrum Pharmaceuticals appears to be a legit concern.

There’s a reason why big companies spend all that money to come up with names that are equally meaningless in all known languages…

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Turning Off Gnome Desktop Tooltips

This probably isn’t applicable to the Latest and Greatest, but for the Ubuntu 8.04 version used by EMC…

gconftool -s --type=bool /apps/panel/global/tooltips -enabled false

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How Not To Say Thank You

Just got a nice thank-you email from the mumble organization after filling out a survey form…

Thank you for taking the mumble Survey survey. Your input is very valuable to us in designing our program.
<Delete or replace with a closing such as “Sincerely,”>
<Delete or replace with an image of a signature>
<Delete or replace with a text representation of a signature (e.g. “John Smith”), the title corresponding to signature (e.g. “President”), and the site name>

OK, I appreciate their intent, but … it’s still a bit off-putting.

Hint: always include yourself on the email list, perhaps as a BCC, when you’re setting up a new bulk response. Sometimes what you see on the proofreading screen isn’t what goes out over the wire.

And I’m pretty sure that the “Survey survey” was put out by their Department of Redundancy Department…

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NiMH Automatic Charger: Use the Real Battery Capacity

Tenergy NiMH Charger

Tenergy NiMH Charger

This Tenergy automatic NiMH charger is typical of the breed: pick a charging current to match the cell / pack capacity, then stand back and let it determine full charge.

The instruction sheet reads thusly:

  • For battery pack between 1100 mah and 2100 mah, please use the low level switch — charging rate: 0.9 A
  • For battery pack over 2100 mah, please use the high level switch — charging rate: 1.8 A

Pop quiz: what charging current should you use for a battery pack made from nominal 2300 mAh cells?

I thought so, too, but consider this graph (the full post is there):

Tenergy RTU Pack A Tests - Aug 2009

Tenergy RTU Pack A Tests - Aug 2009

The actual capacity is more like 1600 mAh, not 2300 mAh. Do you set the charge current based on the wildly overoptimistic cell rating or the actual measured capacity?

As you might expect: charge based on the actual measured capacity, because that’s what the battery can handle.

The higher rate actually worked with new cells, but as the packs aged the charger would sometimes grossly overheat them. Bad for the packs, not to mention a bit scary.

The lower rate worked perfectly, although it took me a while to figure that out.

For what it’s worth, this is the charger I hacked a magnetic grapple onto the thermocouple. Much more convenient and considerably more durable than ptui tape.

Memo to Self: One careful measurement is worth a dozen optimistic ratings.

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Kmail to Evolution: Converting Maildir to Mbox

A bit of searching produces this useful PHP routine, which almost worked. Two tweaks got it all the way there:

  • force the correct time zone
  • quote the write-mode parameter in fopen

The changes, with line numbers in parens (line 347 was line 345 before the first change, OK?):

76:  // force timezone
77:  date_default_timezone_set("America/New_York");
347: $this->mboxhnd = fopen($this->mboxfn,'w');

After that, run the script as directed to convert the entire maildir tree in one fell swoop.

cp -a /from-wherever/Mail/ /tmp
cd /tmp
php maildir2mbox.php Mail
ll mboxfiles

The output files appear in the mboxfiles directory adjacent to the top-level maildir directory. Don’t use the -e parameter, which would add a .mbox suffix to each file.

Evolution’s import “feature” is a major pain, as you must import the converted files One. MBOX. File. At. A. Time. Sheesh.

Rather than that, just slide the whole mboxfiles structure into place. Some case changes were in order for my setup, which may be due to historic considerations:

  • Drafts
  • Inbox
  • Outbox
  • sent-mail -> Sent
  • Spam (will become Junk in Evo)
  • Templates (not that I use any)

Then put the mboxfiles directory somewhere on the NFS server and fiddle the Evolution directory structure:

cp -ap mboxfiles /mnt/nfs-place/mail/
cd ~/.evolution/mail
mv local local.base
ln -s /mnt/nfs-place/mail/ local

Evolution will build all its indexes when it first sees the new files, so it’s all good.

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