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.

Author: Ed

Hard Drive Lifetime: Data Points
Three years ago I installed a 1.5 TB WD Elements USB drive as an external backup for the “file server” in the Basement Laboratory. The log files show that the drive started spitting out “short reads” early in October, which means the rust has begun flaking off the platters.

Repeated fsck -fyv /dev/sda1 runs produce repeated failures at various spots, so it’s not in good condition:
```
e2fsck 1.41.14 (22-Dec-2010)
Backup-1.5TB contains a file system with errors, check forced.
Pass 1: Checking inodes, blocks, and sizes
Error reading block 97649088 (Attempt to read block from filesystem resulted in short read) while getting next inode from scan.  Ignore error? yes
... snippage ...
Pass 2: Checking directory structure
Error reading block 104039017 (Attempt to read block from filesystem resulted in short read) while reading directory block.  Ignore error? yes
Force rewrite? yes
Directory inode 26009985, block #26, offset 0: directory corrupted
Salvage? yes
... snippage ...
Pass 4: Checking reference counts
Inode 25903223 ref count is 41, should be 40.  Fix? yes
... snippage ...
Backup-1.5TB: ***** FILE SYSTEM WAS MODIFIED *****

736471 inodes used (0.80%)
10173 non-contiguous files (1.4%)
9367 non-contiguous directories (1.3%)
# of inodes with ind/dind/tind blocks: 119655/12234/0
142996292 blocks used (39.04%)
0 bad blocks
3 large files

276772 regular files
459614 directories
0 character device files
0 block device files
0 fifos
10377447 links
76 symbolic links (72 fast symbolic links)
0 sockets
--------
11113909 files
```
Given that rsnapshot lashes the daily backups together with extensive hard links, so that there’s only one copy of a given file version on the drive, I don’t know what 76 symbolic links might mean.

It’s been spinning up once a day, every day, for about 40 months; call it 1200 power cycles and you’ll be close. The usual runtime is about 10 minutes, giving the poor thing barely enough time to warm up.

One data point does not a curve make.

The warranty on new WD Element drives seems to be a year; I have no idea what it was slightly over three years ago, although I’m pretty sure it wasn’t more than three years…

The various desktop boxes around here get powered up once a day, too, but I tend to replace them every few years and have never had a hard drive failure; a few system boards have crapped out, though. The boxes acting as controllers for the 3D printers and the Sherline CNC mill have a much lower duty cycle.
2013-10-23
Nerf Pistol: Red PLA Version

No, not that red PLA, just PLA plastic:

Nerf pistol – on M2 platform

A detailed look at the dart carrier and trigger:

Nerf pistol – build detail – on M2 platform

As you can tell from the stock Makergear HBP, I printed it a while ago. It’s the full-length version of that classic, not the shortened Barbie Pistol for the Thing-O-Matic which has been fending off zombies for the last three years (unsuccessfully, from what I hear).

The finished product is a bit ungainly:

Nerf pistol – loaded

That’s not the proper Nerf dart for the thing, but it’s scavenged from tag sale debris and some day I’ll pick up a pack of the skinny ones.

All the pivot points and the sear spring are 3 mm black ABS filament, mostly for contrast. They’re glued in with dabs of Oatey clear PVC cement, the kind with tetrahydrofuran in addition to the usual hellish mix of acetone and MEK.

I bring it along to my show-n-tells, just so I can say I downloaded and printed a gun long before Defense Distributed made it trendy. Haven’t gotten into any trouble yet, but I’m sure some Zero Tolerance regime will bust my ass one of these days.

It was a big hit with the adolescent males at a Squidwrench event, for some reason. [grin]

2013-10-22
Double Helix Thing

After enduring my OpenSCAD solid modeling class, The Might Thor conjured up a solid model of a Thing he wanted and asked if it was buildable. I added a pair of hemispheres to round off the tops, thinned and widened the baseplate for better adhesion, and Fired the M2:

Double Helix – on platform

I thought the overhang was aggressive, but, while it’s not perfect, it’s not nearly as awful as I expected. Perhaps tinkering with a slightly lower extrusion temperature would help.

It’s far less blocky than the stuff I build!

The OpenSCAD model is his; you get to figure it out on your own. Hint: linear_extrude a pair of circles with a twist.

2013-10-21
Toyota Sienna: New Rear Shocks
After the last annual inspection, the Nice Man told me that the rear shocks were rusted out and, although they still worked and he couldn’t fail the van, he wished he could. After 13 years and 88 k miles, yeah, they looked pretty grim:

Sienna OEM rear shocks – removed

The loose steel snippet came from the bottom of the outer shield; it had completely rusted off and dropped free around the lower mount. I suppose that was what got his attention.

Anyhow, the removal went astonishingly well:
- Back the van out of the garage until the wheels line up with drop to the driveway apron
- Pop inside dress covers over the struts
- Remove top jam nuts, cushion, cups
- Remove bottom bolt from wheel carrier (easily!)
- Spritz penetrating on rubber bushing
- Compress shock, twist until bushing slides free
And the installation was equally smooth:
- Install shock on wheel carrier
- Torque bottom bolt (29 ft·lb)
- Aim strut at hole in body
- Cut restraining wire, guide strut through hole
- Install OEM bottom cup, new cushion & cup, new nylock nut
- Tighten to same length as OEM nut
- Install dress covers
The OEM cup fits snugly into the body hole to center the strut, so it seemed like a Good Idea to reuse it. Despite the rust stain inside the body, it was in reasonable condition.

You’re supposed to jack the van up while fiddling around underneath, but the driveway slopes down from the garage enough to provide access. I did chock the wheels, of course, but not jacking the van and putting it on stands looked like a major safety win right there.

The bottom view, which shows the effect of a dozen New York State winters on ordinary steel:

Sienna replacement rear shocks – bottom

The top view, which shows that the bushings did leak a bit of water over the last decade:

Sienna replacement rear shocks – top

Done!

I suppose, just for completeness, I should do the front shocks, but those aren’t nearly as easy and I’d have to start by buying a spring compressor.
2013-10-20
Cooper’s Hawks

High atop that tree again:

Coopers Hawks in evergreen treetop

The bird on the right seems larger and may be the female of a mated pair, but it’s hard to tell at this distance. They could be siblings from the most recent nest in the area, but hawks aren’t chummy birds.

Search for hawk and you’ll find many more pix; I think they’re photogenic.

Go, hawks, go!

It’s taken at the usual 12x zoom with the 1.7 teleadapter on the Sony DSC-H5. I can’t justify the kilobucks required for a large-sensor SLR with nice long glass, but it’d definitely improve the picture quality around here. [sigh]

2013-10-19
LED Bulb Lifespan vs. Warranty

I picked up a $35 LED bulb that’s allegedly equivalent to a 75 W incandescent, replacing a 100 W equivalent compact fluorescent bulb that an X10 relay switch couldn’t turn off cleanly, for a torchiere floor lamp. ‘Nuff said about early CFL failures.

It has both upward and downward facing LED chips that light up the diffuser and ceiling in equal measure. Both strings are visible from the side due to the heavy molded plastic lens around the chips:

LED Bulb

Some interesting bits from the package:

Home Depot LED Bulb Warranty

A 22.8 year lifespan at three hours per day works out to 24.983×10³ hours. I wish I could have heard the arguments about whether they could claim a 23 year lifespan…

At the same duty cycle, the 5 year warranty covers 5.479×10³ hours. Huh.

The URL at the bottom leads to some general info, but nothing you didn’t know already.

It works well enough, but at $35 it’s really a capital investment that I suspect will never actually pay for itself…

2013-10-18
Dutchess County Rail Trail Ride

The DCRT folks held a “soft opening” last week at the bridge over Rt 55 completing the rail trail from Hopewell Junction to the Walkway Over the Hudson; the Hudson Valley Rail Trail continues westward to Lloyd. I hadn’t actually planned to ride the whole thing, but Monday was a lovely day and, hey, why not?

So here’s what a pleasant, mostly off-road 36 mile ride looks like:

KE4ZNU Rail Trail Ride – 2013-10-14

Hadn’t realized it was Columbus Day until well into the ride, which accounted for a Hudson River crossing at 3 mph embedded in a solid 1.5 mile scrum. Being no fool, I returned over the Poughkeepsie (a.k.a. Mid Hudson) Bridge.

2013-10-17