Posts Tagged Repairs

LibreOffice Impress vs. NFS Network Shares vs. Caching

Whenever I put together a presentation, LibreOffice Impress gradually grinds to a halt with images in the slide thumbnails repeatedly updating and never stabilizing; eventually, LO crashes and sends a crash report to whoever’s watching. This may be due to my enthusiastic use of images to get my point(s) across, although I’m just not gonna back down from that position:

LibreOffice Impress - Thumbnail thrashing
LibreOffice Impress – Thumbnail thrashing

That’s a screenshot of a small thumbnail, enlarged for visibility, so it doesn’t look that crappy in real life.

Perhaps the problem arises because I insert the images as links, rather than embedding them to create a monolithic presentation file roughly the size of all outdoors?

Searching with the obvious keywords produces tantalizing hints concerning LO’s file locks clashing with NFS network share locking, which seems appropriate for my situation with all the files living on the grandiosely named file server (a headless Optiplex) in the basement.

The suggestions include making sure the NFS locking daemon is active, but I have NFC about how that might work in practice. The lockd daemon is running, for whatever that’s worth.

Seeing as how I’m the only one editing my LO presentations, disabling LO’s locks has little downside and requires tweaking one character in one line inside /usr/bin/libreoffice:

# file locking now enabled by default
SAL_ENABLE_FILE_LOCKING=0
export SAL_ENABLE_FILE_LOCKING
<<< blank line to show off underscores above >>>

After a brief bout of good behavior, Impress resumed thrashing and stalling.

Copying the entire presentation + images to the SSD inside my desktop PC didn’t improve the situation.

More searches on less obvious keywords suggested disabling the Impress “background cache”, whatever that might be:

Tools → Options → Impress → General → Settings

Then un-check the ☐ Use background cache item, which may be the last vestige of the now-vanished memory usage and graphics cache size settings from previous versions.

In any event, disabling the cache had no effect, so it’s likely a problem deep inside LibreOffice where I cannot venture.

It autosaves every ten minutes and I must restart it maybe once an hour: survivable, but suboptimal.

There seems to be an improvement from Version 6.0.7 (Ubuntu 18.04 LTS) to Version 6.2.8 (Manjaro rolling release), although it’s too soon to tell whether it’s a fix or just different symptoms.

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Subaru Forester Rear Wiper Disassembly

You’re supposed to just rotate the wiper blade holder and have it pop out of the mount on the end of the arm:

Subaru Forester - rear wiper blade mount
Subaru Forester – rear wiper blade mount

The blade holder has two opposed pegs fitting into those curved notches to the right of the hook for the holder’s pivot, with the intent of preventing it from rotating too far and sliding out. I was unwilling to apply sufficient force to disengage those pegs, as the penalty for breaking the wrong piece of plastic seemed very high. Apparently, the pegs should ride up over the slightly lower edge of their notch, bending the holder’s sides outward as they do.

So I jammed a little screwdriver beside one of the pegs, managed to encourage it out of its notch, repeated the treatment on the other side, and the blade holder popped right out.

The front wiper arms have J-hooks on their ends and disengage easily, at least after you realize the flat panel on the blade holder is actually a latch you’re suppose to pull up-and-out to release the hook. This goes more easily when assisted with the aforementioned small screwdriver.

The blades were in good shape after five years, mostly because the Forester spends most of its time in the garage. A trio of silicone wipers should last the rest of its life, with the OEM wipers tucked into the spare tire well Just In Case.

Back in the day, one could replace just the blades, not the entire holder, but I suppose this is progress.

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MPCNC Drag Knife Holder: Lock Screw

While calibrating the MPCNC’s probe camera offset for the drag knife holder, this happened:

Drag Knife - vertical escape
Drag Knife – vertical escape

Well, at least it’s centered on the target:

Drag Knife - vertical escape - detail
Drag Knife – vertical escape – detail

This happened a few times before, because my fingers don’t fit neatly inside the drag knife holder to tighten the lock ring:

Drag Knife - LM12UU ground shaft - assembled
Drag Knife – LM12UU ground shaft – assembled

[Update: The lock ring keeps the holder at a fixed position inside the 12 mm shaft and doesn’t affect the blade directly. When the ring works loose, the threaded holder can rotate to expose more blade and, in this case, stab deeper into the target. ]

So I turned & knurled an aluminum ring, then tapped a 3×0.5 mm hole for a lock screw plucked from the Drawer o’ Random M3 Screws:

Drag Knife - lock screw - side
Drag Knife – lock screw – side

A view looking along the screw shows a bit more detail around the spring:

Drag Knife - lock screw - front
Drag Knife – lock screw – front

The general idea is to set the blade extension, then tighten the lock screw to hold it in place, without relying on the original brass lock ring, shown here while cutting a boss for the spring:

Drag Knife - turning spring recess
Drag Knife – turning spring recess

The lock screw’s knurled handle just barely kisses the NPCNC’s black tool holder ring, so my guesstimated measurements were a bit off. Clamping the knife holder one itsy higher in the tool holder solved the problem.

I cranked on 300 g of spring preload and, squashed like that, the spring’s rate is now 75 g/mm. Cutting at Z=-1 mm should suffice for laminated paper slide rule decks.

The original sizing doodle:

Drag Knife Holder - lock screw ring doodle
Drag Knife Holder – lock screw ring doodle

The short 18 mm section clears the inside of the LM12UU bearing, although it could be a millimeter shorter. The 19 mm section comes from the 3/4 inch aluminum rod I used, skim-cut to clean it up.

If I ever remake this thing, it needs a major re-think to get all the dimensions flying in formation again.

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Baofeng Bike Helmet Headset Wiring Repair

The audio output wire from the Baofeng UV-5R to my bike helmet headset adapter broke after a year and a half, far longer than I expected:

Baofeng - broken spkr wire
Baofeng – broken spkr wire

It’s the green one, over on the left, pulled out of the heatstink tubing that should have provided some strain relief, having broken at the solder joint to the resistor.

A quick & easy fix, after which I reapplied even more tape to hold everything in place.

Maybe it’ll last two years this time around …

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Photo Lamp Mount: Moah Plastic!

One of the cold shoe mounts I made for the photo lamps cracked:

Photo Lamp Mount - fractured
Photo Lamp Mount – fractured

It’s done in PETG with my more-or-less standard two perimeter threads and 15% 3D honeycomb infill, which is Good Enough™ for most of my parts. In this case, there’s obviously not nearly enough plastic in there!

Redoing it with three perimeters and 50% infill should improve the situation, even though it looks identical on the outside:

Photo Lamp Mount - reinstalled
Photo Lamp Mount – reinstalled

I didn’t replace the other mount. If it breaks, it’ll get the same 50% infill as this one. If this one breaks, I’ll try 75%.

An easy fix!

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Huion H610Pro (V2) Tablet vs. xsetwacom

For unknown reasons, likely having to do with ordinary system updates, both the Huion H610Pro (V2) tablet’s device name and the display output’s name have changed. This came to light when I discovered the tablet’s stylus was no longer constrained to the landscape display, which worked fine when I set it up barely a month ago.

Running the setup command manually:

xsetwacom --verbose set "HUION Huion Tablet Pen stylus" MapToOutput "DP-1"
... Display is '(null)'.
... 'set' requested for 'HUION Huion Tablet Pen stylus'.
 <<< snippage >>>
... Checking device 'HUION Huion Tablet stylus' (11).
... Checking device 'HUION Huion Tablet eraser' (19).
Cannot find device 'HUION Huion Tablet Pen stylus'.

Apparently, the device formerly known as HUION Huion Tablet Pen stylus is now called HUION Huion Tablet stylus.

Fine, I can live with that. Try again:

xsetwacom --verbose set "HUION Huion Tablet stylus" MapToOutput "DP-1"
... Display is '(null)'.
... 'set' requested for 'HUION Huion Tablet stylus'.
 <<< snippage >>>
... Checking device 'HUION Huion Tablet stylus' (11).
... Checking device 'HUION Huion Tablet eraser' (19).
... Device 'HUION Huion Tablet stylus' (11) found.
... Found output 'VGA-1' (disconnnected)
... Found output 'DP-1' (disconnnected)
... Found output 'HDMI-1' (disconnnected)
... Found output 'DP-2' (connected)
... CRTC (2560x0) 1440x2560
... Found output 'HDMI-2' (disconnnected)
... Found output 'DP-1-8' (connected)
... CRTC (0x0) 2560x1440
... Found output 'DP-1-1' (disconnnected)
Unable to find output 'DP-1'. Output may not be connected.

Apparently, the video output formerly known as DP-1 has fissioned into DP-1-1 and DP-1-8, with only the latter connected. Weirdly, nothing happened to DP-2.

Once more, into the bleach:

xsetwacom --verbose set "HUION Huion Tablet stylus" MapToOutput "DP-1-8"
... Display is '(null)'.
... 'set' requested for 'HUION Huion Tablet stylus'.
 <<< snippage >>>
... Checking device 'HUION Huion Tablet stylus' (11).
... Checking device 'HUION Huion Tablet eraser' (19).
... Device 'HUION Huion Tablet stylus' (11) found.
... Found output 'VGA-1' (disconnnected)
... Found output 'DP-1' (disconnnected)
... Found output 'HDMI-1' (disconnnected)
... Found output 'DP-2' (connected)
... CRTC (2560x0) 1440x2560
... Found output 'HDMI-2' (disconnnected)
... Found output 'DP-1-8' (connected)
... CRTC (0x0) 2560x1440
... Setting CRTC DP-1-8
... Remapping to output area 2560x1440 @ 0,0.
... Transformation matrix:
... 	[ 0.640000 0.000000 0.000000 ]
... 	[ 0.000000 0.562500 0.000000 ]
... 	[ 0.000000 0.000000 1.000000 ]

Well, that worked.

Actually, I had to constrain the stylus to DP-2, then jam it back on DP-1-8, to spread the tablet’s horizontal extent over the entire monitor. Updating the startup script started the tablet properly the next morning.

The new device name certainly makes more sense and, perhaps, the X output connection now recognizes the landscape monitor’s ability to pass its DisplayPort video stream along to a second monitor.

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Blackburn Flea Bike Headlight

A Blackburn Flea bike headlight and its USB charger emerged from the packs on our Young Engineer’s Tour Easy, but the battery was completely defunct. With nothing to lose, I applied a small screwdriver to crack the case:

Blackburn Flea - opening case
Blackburn Flea – opening case

The battery is a single cylindrical lithium cell:

Blackburn Flea - battery
Blackburn Flea – battery

The USB charger seemed defunct, as it produced only a few dozen millivolts when connected and plugged into its wall wart. Cracking its case revealed a tiny buck power supply with no obvious damage, but also no output.

So I manually charged the cell:

Blackburn Flea - external recharge
Blackburn Flea – external recharge

Definitely not recommended practice, but a bench supply set to 4.1 V and current-limited to 100 mA gets the job done: the current stays at 100 mA while the voltage rises to 4.1 V, then the current drops to just about zero over the next few hours with cell held at 4.1 V.

Unfortunately, the cell really was defunct, even after a few cycles, so I conjured a not-dead-yet lithium cell from the heap:

Blackburn Flea - measurement setup
Blackburn Flea – measurement setup

Given a good supply, the Flea still works perfectly:

Blackburn Headlight - Kyocera Li-ion - 50 mA-div
Blackburn Headlight – Kyocera Li-ion – 50 mA-div

The yellow trace shows the battery holding at 4 V while the LED current runs at 150 mA (3 div × 50 mA/div). You wouldn’t want to run ordinary 5 mm LEDs at nearly 40 mA, but Blackburn surely specified good parts.

Replacing the Flea’s internal cell seems impossible, given its peculiar form factor, and grafting the PCB to an external cell makes no sense, given that it’d then need a custom bike mount.

So another chunk of electronics goes in the e-waste box.

Ride on!

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