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

Xubuntu 12.04: Some Steps Forward, Some Steps Back
The continuing saga of trying to run a Linux desktop with two monitors (one rotated in portrait mode), separate X sessions, two trackballs, and a Wacom graphics tablet continue with Xubuntu 12.04. KDE continues to not work quite right with dual monitors, Gnome seems to be dead in the water, Unity wants to be a touch-screen UI when it grows up, and Linux Mint introduces yet another not-quite-baked UI. The breathtaking churn in Linux infrastructure continues, rendering everything I’d figured out with respect to FDI / HAL / udev configuration lagely irrelevant.

For lack of a better alternative, I’ve installed Xubuntu, which is now a deprecated (available, but unsupported) version of Ubuntu. Configuring separate X sessions on two monitors requires the proprietary nVidia driver. The XFCE display configurator falls over dead when confronted with two screens and the xrandr extension seems unworkable. Fortunately, I’d left a bit of commented-out cruft in the xorg.conf file that worked in Xubuntu 10.10 and could copy the whole file over with only one change:
```
Section "Screen"
    Identifier     "Portrait"
    Device         "GF9400_1"
    Monitor        "Dell2005FP"
    DefaultDepth    24
    Option         "TwinView" "0"
    Option         "metamodes" "DFP-1: 1680x1050 +0+0"
    Option         "NoLogo" "Off"
#    Option         "RandRRotation" "On"
    Option         "Rotate" "CCW"
    SubSection     "Display"
        Depth       24
    EndSubSection
EndSection
```
Configuring two trackballs with the XFCE utility remains surprisingly easy: the Kensington is left-handed and the Logitech is right-handed.

Swapping buttons 2 and 3 on the Wacom stylus poses a bit more of a challenge. Doing it on a per-session basis seems straightforward:
```
xsetwacom set "Wacom Graphire3 6x8 stylus" button 2 3
xsetwacom set "Wacom Graphire3 6x8 stylus" button 3 2
```
You’d put those into a script and tell XFCE to auto-run it when you sign in, but that doesn’t handle hotplugging. I don’t hotplug the tablet, but random static glitches knock the USB hub into a tailspin and cause the same effect, so I jammed the lines that used to be in xorg.conf into /usr/share/X11/xorg.conf.d/50-wacom.conf:
```
Section "InputClass"
        Identifier "Wacom class"
        MatchProduct "Wacom|WACOM|Hanwang|PTK-540WL|ISD-V4"
        MatchDevicePath "/dev/input/event*"
        Driver "wacom"
        Option "Button2" "3"
        Option "Button3" "2"
EndSection
```
I’m certain there’s a different location for those that fits in with whatever the overall design might be these days, but I’m kinda tired of figuring this stuff out.

The Wacom drivers in Ubuntu 12.04 no longer permit restricting the tablet’s range to a single X session (xsetwacom set ... MapToOutput "HEAD-0" assumes you’re using xinerama with a single X session across two monitors), which sprawls the tablet’s limited resolution across both screens and leaves a big unusable rectangle in the lower third of the left side. This is not progress in a positive direction, but there’s no workaround.

That workaround for the upstart Pachinko machine also applies to this box. The minute-long pause while NFS hauls itself to its feet isn’t attractive: you see VT 1 with the bare white-on-black command-line login prompt, but if you actually log in, things get very ugly, very quickly.

Restoring the usual verbose Unix-oid startup messages requires tweaking /etc/default/grub to set noquiet nosplash, then running update-grub.

Search the blog with the obvious keywords to get my earlier posts on all these topics…
2012-10-19
Tour Easy + BOB YAK Trailer = More Cargo Hauling

A trailer load of 62 pounds of sweet potatoes from the Vassar Farms plot:

Tour Easy – BOB Yak – sweet potatoes

Followed by 42 pounds of apples from Prospect Hill, a PYO orchard across the Hudson:

Tour Easy – BOB Yak – with 42 pounds of apples

Folks haul heavier loads than those across the continent and around the world, but … a dozen miles or so is enough for me!

And, yes, those are rather large sweet potatoes. The biggest one, a Korean Purple, weighed 6 pounds:

6 pound sweet potato

2012-10-18
Screwdriver Rack

A while back I picked up one of Harbor Freight’s cheap screwdrivers sets; the largest two drivers far exceed my simple needs, but the smaller screwdrivers work surprisingly well. I couldn’t figure out where to store the things, as they’re used often enough to remain ready to hand, while being too bulky for any of the drawers. Emboldened by my success with those shoe latch springs, I decided to bend some coat hanger wire into simple clips that grab the screwdrivers around their waists:

Screwdriver clip – rear view

The first step forms a loop where the mounting screw will go; squeezing the wire around the pin with pliers made a reasonably good imitation of a screw hole:

Screwdriver clip – screw bend

The next two bends shape the wire to the arms; I eventually figured out that bending the wire ends to a mutual right angle worked out better than the acute angle you see here:

Screwdriver clip – second bend

Bending both wires at a right angle formed the arms:

Screwdriver clip – arm bend

Two more bends in each arm finished off the clip:

Screwdriver clip – entry bends

I chopped up a coat hanger with smaller diameter wire to make clips for the smallest screwdrivers with narrower handles.

Repeat that a dozen times, drill pilot holes into a ready-to-use bit of scrap lumber, screw the clips with 3/4 inch flat-head screws, add four more holes on the right for finishing nails to hold the red screwdrivers (which have suitable holes in their handles), screw the whole affair to the bottom of the floor joist, and it’s all good:

Screwdriver rack on floor joist

After running the first half dozen screws with great effort, I fetched the beeswax and the rest slid right into place.

The larger driver handles stick up inconveniently far behind the fluorescent lamp fixture that’s barely visible along the top, but (I’m pretty sure) I won’t use those nearly enough for that to be a problem.

I suppose I should dip the raw ends of the wires in goop to avoid harpooning myself; I think I’ll mostly handle the screwdrivers by their shafts, so maybe that won’t be a problem, either.

Memo to Self: Use the beeswax!

2012-10-17
Splinting an Umbrella Strut
One of the ribs in the six-passenger umbrella we keep in the van snagged on something and snapped its fitting on the spreader strut:

Umbrella strut – broken connector

This being wonderful engineering plastic that cannot be solvent-bonded, epoxy is the only adhesive that will work. However, those joints undergo tremendous stress in a deployed umbrella, so a bare epoxy joint won’t have enough strength for the job. What to do?

Wonder of wonders, when I got the umbrella into the Basement Laboratory Repair Wing, I discovered:
- The not-quite-round strut fitting stub slipped right into a short brass tube from the heap and
- Just enough of the fitting remained on the rib to anchor the tubing
A silicone tape wrap kept most of the epoxy inside while it cured:

Umbrella strut – epoxy curing

Clearing off a few blobs made it all good:

Umbrella strut – brass tubing splint

We don’t play golf, but such a big umbrella keeps most of the rain off two people; it’s a tchotchke from back when Mary worked at IBM (hence the color scheme). We call it our “six-passenger” umbrella because it looks about that big when we deploy it…
2012-10-16
Monthly Picture: Laboratory Study of the Grasshopper

My father drew this in his Sophomore Biology Laboratory Notebook:

Laboratory Study of the Grasshopper

Can you imagine the attention span required to draw that with no obvious errors? The next four pages contain a hand-written discussion of the grasshopper, with two corrections; he filled the entire notebook using a pen and four colors of fluid ink.

Here’s a closer look at the grasshopper (clicky for more dots):

The Grasshopper

I cannot imagine assigning that task to present-day students…

Things were different in 1927, when he was 17 years old. They were about to get really different; 15 years later he was in the South Pacific.

2012-10-15
Grace Under Pressure

We toured the USS Albacore (AGSS 569) in Portland NH and found this placard in the forward Escape Trunk (which doubled as the normal hatch during the sub’s nautical lifetime):

Escape Trunk Operating Procedure

One of my relatives is a submariner who seems calm & collected enough to remember that entire checklist in an emergency.

The heads bore similar placards, along the lines of the classic scene in 2001: A Space Odyssey.

The camera lens they used for their virtual tour pictures would lead you to believe there was actually enough space inside the sub to inhale. That was not the case and I was very glad to have only half a dozen other people touring the sub with us.

Our hotel room (on the top floor of Wentworth by the Sea, egad) had a good view of the Portsmouth Naval Shipard (also see Wikipedia) across the Piscataqua River, where the USS Miami (SSN 775) remains discreetly under cover.

2012-10-14
The Value of Childhood Rhymes

Saw this in Lowell MA outside the Bootts Cotton Mill Apartments:

DO NOT ENTER – unusual date

The way I learned it:

Thirty days hath September,
April, June, and November.
All the rest have thirty-one,
Except February, which is all messed up.

Maybe the River Walk reopens on the Twelfth of Never?

2012-10-13