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.

Tag: Repairs

If it used to work, it can work again

Scrubbing Old Hard Drives
The shelf that collects old hard drives filled up, so I’ve been wiping the data before recycling them. This takes a while, but we know what happens when your hardware falls into unexpected hands. The routine goes a little something like this…

Set the drive’s jumper to Master, plug the drive into the USB adapter, plug the adapter directly into a USB port on the PC (because outboard hubs tend to be flaky), make sure there’s no valuable data, unmount.
```
time sudo dd if=/dev/urandom of=/dev/sdc bs=4096
[sudo] password for ed: 
dd: error writing ‘/dev/sdc’: No space left on device
73259047+0 records in
73259046+0 records out
300069052416 bytes (300 GB) copied, 22276.7 s, 13.5 MB/s

real	371m19.003s
user	0m22.884s
sys		370m34.906s 
```
Good old dd works for me; the only trick is not obliterating the system’s main hard drive with a simple finger fumble. Numbers from /dev/urandom suffice for this purpose; that’s where most of the packaged programs get their data, too. I do hardcore style, just because.

Ordinary desktop drives, at least those from long ago, can write at a bit over 12 MB/s → 40 GB/h on the average, with the higher peak rates that generally appear in the drive descriptions remaining an occasional sight. They won’t go much faster, even when plugged directly into the system board, but it’s not as if I sit there waiting until it’s done. USB 2.0 “high speed” transfers can hit 60 MB/s, including all the overhead, so that’s not the limiting factor; I’d expect the adapter’s firmware to throttle the data long before the bus strangles.

Use gparted to write a fresh partition table with a single NTFS (because the next user will probably run Windows) partition labeled Scrubbed spanning the entire drive.

Then stack the drive neatly on the outbound heap:

Scrubbed hard drives

That cardboard box isn’t quite as full of unscrubbed drives as it was a few weeks ago.

The stack in the back contains all those worthless 30 to 80 GB 5400 RPM drives from old Dells, plus a few 1.5 and 2.0 (!) GB drives from who knows where. I have a plan for those platters…
2015-10-23
NSA Zipper Pull Tab: Recovered!

The NSA pull tab went missing from my belt pack on the way back from a Squidwrench meeting and, despite diligent searching, remained missing for a several weeks. It reappeared from far under the Forester’s front seat, still attached to the severely eroded YKK zipper pull tab:

Eroded YKK Zipper Tab

A stout jump ring from the heap should avoid that problem for the foreseeable future:

NSA Zipper Pull – restored

Dang, I missed that thing…

2015-10-20
Realigning Tweezer Tips

It’s been a while since the last time I repointed the tweezer collection, but eventually they get to the, ah, point where you can’t pick up a hair:

Misaligned tweezer jaws

In the midst of shaping the tip of another tweezer:

Tweezer jaw tips

The jaws meet at the point, but those end bevels definitely need more attention!

All in all, a pleasant half hour of Quality Shop Time:

Realigned tweezers

2015-10-18
Beckman DM73 Circuitmate Multimeter: Ground Clip

Among the many treasures Mad Phil left me was a Beckman DM73 CircuitMate multimeter (manual at the Boat Anchor Manual Archive):

Beckman DM73 – new ground clip

Although it’s rated to 500 V, it violates the fundamental principle of high-voltage electronics debugging:

Always keep one hand in your pocket!

The scorched and truncated probe tip on the “ground wire” shows Phil slipped at least once:

Beckman DM73 – probe tip

After far too long, I sacrificed a black multimeter probe from the heap, soldered an alligator clip on the end, and, henceforth, will use it appropriately. Mostly, I never do any high-voltage work, but you never know.

I suppose I should splice that nice black probe onto the end of the Beckman wire for low-voltage work…

2015-10-14
Leitz Trinovid Eye Tube Lube

We’ve had this/these Leitz Trinovid 8×20 binocular(s) approximately forever:

Leitz Trinovid binoculars

The logo indicates we bought them before Leitz became Leica in 1986…

Recently, the eye cups became difficult to pull out. The problem seemed to lie in the seal around the exterior of each tube, rather than with the internal mechanism, so I eased the tiniest possible drop of clock oil into each gap, spun the tubes, cycled them in-and-out, and wiped off essentially all of the oil as it spread over the exterior of the tubes.

The eye cups work fine again!

Frankly, I felt a like a Visigoth upgrading the Large Hadron Collider, but I trusted those old-school Leitz engineers would protect their optics from everything happening outside the sealed tubes.

The new Leica Trinovids carry 8×42 optics, with 8×20 glass in the Ultravid Compact Field Optics line. They’re definitely spendy, but probably less in constant dollars than the ones we have; in any event, they’re definitely a a buy-and-hold investment.

2015-10-12
Road Conditions: October 2015 Summary

It took a while, but the owners of Janet Drive did a commendable job of resurfacing the giant potholes that were consuming the parking lot entrance:

Janet Dr at 708 Dutchess Turnpike entrance – 2015-10-05

That patch covers all the holes, has a smooth surface, and neatly joins the adjacent pavement without huge bumps. It’s entirely possible to do good repairs, if you just hire the right contractor.

Which doesn’t happen if you’re NYSDOT, unfortunately, as they regards a few random hand-tamped blobs on a section of Rt 44 (and Bike Rt 44, for whatever that’s worth) as entirely adequate:

Rt 44 – 695 at Quest Diagnostics – 2015-10-05 – no progress

The sinkhole on Rt 376 that we must dodge maybe four times every week continues to grow:

Rt 376 2015-10-05 – Northbound milepost 1110 – sinkhole

Somebody who should know better suggested the NYSDOT crew just ran out of asphalt after patching all around the sinkhole that I’d reported back in July, but …

The NYSDOT Bicycle and Pedestrian Coordinator (yeah, she exists) assured me the engineers were studying the signal timing and would contact me directly:

Burnett at Rt 55 2015-08-31 – Yellow 8 s after green with cars

That hasn’t happened after four months, so I’d say NYSDOT uses the word “study” to mean “stonewall”.

There are more examples, but, to make a long gripe short, I’ve (once again) proven to my own satisfaction that there’s no point in reporting bicycle-related maintenance problems to NYSDOT: it only annoys them and they retaliate by making things worse.

We just keep riding…

2015-10-08
Debranded HP w2408 Monitor Cap

Quite some time ago, I picked up a nice monitor that turned out to be a debranded (all OEM labels removed or covered) HP w2408. It eventually became erratic, refusing to turn on or return from power-save mode, so I took it apart. All the caps looked good and seemed to have low ESR, except for the big one in the middle of the power supply board:

HP 2408 monitor power supply – HV cap

It’s 30 mm in diameter, with 10 mm lead spacing, and stands a squat 26 mm tall, ignoring a millimeter or two of bulge in its should-be-flat black cap:

HP 2408 monitor power supply – HV cap bulge

Having never seen one of that size before, I sent a note and picture to folks who sell re-capping kits for monitors, in the hope that they’ll have a lead.

Otherwise, it’s e-trash…

2015-10-07