SCP Warning Label Earrings: Rattlecan Feasibility Test

Our Young Engineer provided different specs for earrings than I’d been using, which prompted a quick-n-dirty test to see how they might come out:

SCP Warning Labels - test 1
SCP Warning Labels – test 1

The images come from the SCP Wiki with tweakage for better contrast:

SCP warning signs - BW 3x3
SCP warning signs – BW 3×3

Then I traced them into LightBurn vectors suitable for engraving, added hanging holes, and fit a perimeter cutout. This being a test, I took a number of shortcuts resulting in slightly off-center engravings and ignored a number of image botches (most notably in the Inconsistent Topology figure.

A quick painting fixture kept (most of) the rattlecan paint off the edges:

SCP Warning Labels - fixture clamping
SCP Warning Labels – fixture clamping

The acrylic is old enough to have brown paper protective layers, rather than fancy plastic sheets. I peeled various combinations and shot various sides with purple:

SCP Warning Labels - purple coat
SCP Warning Labels – purple coat

Remove some, flip others over, and hit ’em with yellow:

SCP Warning Labels - yellow coat
SCP Warning Labels – yellow coat

I expected purple markings over a yellow background to look best:

SCP Warning Labels - purple over yellow
SCP Warning Labels – purple over yellow

But the inverse version seems more contrasty (ignore the off-center cutout):

SCP Warning Labels - yellow over purple
SCP Warning Labels – yellow over purple

I think the purple-on-clear version would look better with edge-lit acrylic:

SCP Warning Labels - purple over clear
SCP Warning Labels – purple over clear

The 0.15 mm line spacing seems too coarse, but trying to get a perfectly flat engraved bottom seems futile.

A second coat of paint on the engraving would definitely boost the contrast.

If you were going to do this for real, you’d definitely recreate the images with vectors right from the start, using the original images as inspiration.

All in all, I like ’em, but there’s some improvement required before anybody else does!

Copying Action Camera Video Files: Now With Arrays

Using Bash arrays is an exercise in masochism, but I got to recycle most of the oddities from the previous script, so it wasn’t a dead loss.

The cameras use individually unique / screwy / different filesystem layouts, so the script must have individual code to both copy the file and decapitalize the file extensions. This prevents using a single tidy function, although laying out the code in case statements keyed by the camera name helps identify what’s going on.

My previous approach identified the MicroSD cards by their UUIDs, which worked perfectly right up until the camera reformats the card while recovering from a filesystem crash and installs a randomly generated UUID. Because there’s no practical way to modify an existing UUID on a VFAT drive, I’m switching to the volume label as needed:

#-- action cameras and USB video storage
UUID=B40C6DD40C6D9262	/mnt/video	ntfs	user,noauto,uid=ed	0	0
UUID=B257-AE02		/mnt/Fly6	vfat	user,noauto,uid=ed	0	0
#UUID=0000-0001		/mnt/M20	vfat	user,noauto,uid=ed	0	0
UUID=3339-3338		/mnt/M20	vfat	user,noauto,uid=ed	0	0
LABEL=AS30V		/mnt/AS30V	exfat	user,noauto,uid=ed	0	0
LABEL=C100-0001		/mnt/C100_1	vfat	user,noauto,uid=ed	0	0
LABEL=C100-0002		/mnt/C100_2	vfat	user,noauto,uid=ed	0	0
UUID=0050-0001		/mnt/M50	vfat	user,noauto,uid=ed	0	0

In particular, note the two UUIDs for the M20 camera: there’s a crash and reformat in between those two lines. The two C100 cameras started out with labels because the M20 taught me the error of my ways.

The script simply iterates through a list array of the cameras and tries to mount the corresponding MicroSD card for each one: the mount points are cleverly chosen to match the camera names in the array. Should the mount succeeds, an asynchronous rsync then slurps the files onto the bulk video drive.

With all the rsync operations running, the script waits for all of them to complete before continuing. I don’t see much point in trying to identify which rsync just finished and fix up its files while the others continue to run, so the script simply stalls in a loop until everything is finished.

All in all, the script scratches my itch and, if naught else, can serve as a Bad Example™ of how to get the job done.

A picture to keep WordPress from reminding me that readers respond positively to illustrated posts:

A pleasant day for a ride - 2023-06-01
A pleasant day for a ride – 2023-06-01

Ride on!

The Bash script as a GitHub Gist:

# This uses too many bashisms for dash
source /etc/os-release
echo 'Running on' $PRETTY_NAME
if [[ "$PRETTY_NAME" == *Manjaro* ]] ; then
dm='sudo dmesg'
elif [[ "$PRETTY_NAME" == *Ubuntu* ]] ; then
echo 'New distro to me:' $PRETTY_NAME
echo ' ... which rename command is valid?'
echo Check for good SD card spin-up
$dm | tail -50
echo ... Ctrl-C to bail out and fix / Enter to proceed
read junk
thisdate=$(date --rfc-3339=date)
echo Date: $thisdate
# MicroSD / readers / USB drive defined in fstab
# ... with UUID or PARTID as appropriate
echo Mounting bulk video drive
sudo mount /mnt/video
if [ $? -ne 0 ]; then
echo '** Cannot mount video storage drive'
# Show starting space available
df -h /mnt/video
# list the cameras
declare -a cams=( AS30V Fly6 M20 M50 C100_1 C100_2 )
declare -A targets=( \
[AS30V]=/mnt/video/AS30V/$thisdate \
[Fly6]=/mnt/video/Fly6/DCIM \
[M20]=/mnt/video/M20/$thisdate \
[M50]=/mnt/video/M50/$thisdate \
[C100_1]=/mnt/video/C100_1/$thisdate \
[C100_2]=/mnt/video/C100_2/$thisdate \
declare -A PIDs
declare -A Copied
echo Iterating through cameras: ${cams[*]}
for cam in ${cams[*]} ; do
printf "\nProcessing: $cam\n"
sudo mount $mpt
if [ $? -eq 0 ]; then
echo " Start $cam transfer from $mpt"
echo " Make target directory: $target"
mkdir $target
case $cam in
( AS30V )
rsync -ahu --progress --exclude "*THM" $mpt/MP_ROOT/100ANV01/ $target &
( Fly6 )
rsync -ahu --progress $mpt /mnt/video &
( M20 )
n=$( ls $mpt/DCIM/Photo/* 2> /dev/null | wc -l )
if [ $n -gt 0 ] ; then
echo " copy M20 photos first"
rsync -ahu --progress $mpt/DCIM/Photo/ $target
echo " cmd: rsync -ahu --progress $mpt/DCIM/Movie/ $target"
rsync -ahu --progress $mpt/DCIM/Movie/ $target &
( M50 )
n=$( ls $mpt/DCIM/PHOTO/* 2> /dev/null | wc -l )
if [ $n -gt 0 ] ; then
echo " copy M50 photos first"
rsync -ahu --progress $mpt/DCIM/PHOTO/ $target
rsync -ahu --progress $mpt/DCIM/MOVIE/ $target &
( C100_1 | C100_2 )
n=$( ls $mpt/DCIM/Photo/* 2> /dev/null | wc -l )
if [ $n -gt 0 ] ; then
echo " copy $cam photos first"
rsync -ahu --progress $mpt/DCIM/Photo/ $target
rsync -ahu --progress $mpt/DCIM/Movie/ $target &
( * )
printf "\n**** Did not find $cam in list!\n"
echo " PID for $cam: " "${PIDs[$cam]}"
(( Running++ ))
echo " skipping $cam"
printf "\n----- Waiting for all rsync terminations\n"
echo PIDs: "${PIDs[*]}"
if [ $Running -eq 0 ] ; then
echo No rsyncs started, force error
while [ $Running -gt 0 ] ; do
echo " waiting: $Running"
wait -n -p PID
rcsum=$(( rcsum+$rc ))
echo RC for $PID: $rc
(( Running-- ))
echo All rsyncs finished
if [ $rcsum -eq 0 ] ; then
echo '----- Final cleanups'
for cam in ${cams[*]} ; do
if [ "${Copied[$cam]}" -eq 1 ] ; then
echo Cleanup for: $cam
echo Target dir: $target
case $cam in
( Fly6 )
find $target -name \*AVI -print0 | xargs -0 $ren -v -f 's/AVI/avi/'
rm -rf $mpt/DCIM/*
( AS30V )
find $target -name \*MP4 -print0 | xargs -0 $ren -v -f 's/MP4/mp4/'
rm $mpt/MP_ROOT/100ANV01/*
( M50 )
find $target -name \*MP4 -print0 | xargs -0 $ren -v -f 's/MP4/mp4/'
rm $mpt/DCIM/MOVIE/*
n=$( ls $mpt/DCIM/PHOTO/* 2> /dev/null | wc -l )
if [ $n -gt 0 ] ; then
echo placeholder $cam
rm $mpt/DCIM/PHOTO/*
( * )
find $target -name \*MP4 -print0 | xargs -0 $ren -v -f 's/MP4/mp4/'
find $target -name \*JPG -print0 | xargs -0 $ren -v -f 's/JPG/jpg/'
rm $mpt/DCIM/Movie/*
n=$( ls $mpt/DCIM/Photo/* 2> /dev/null | wc -l )
if [ $n -gt 0 ] ; then
echo placeholder $cam
rm $mpt/DCIM/Photo/*
sudo umount $mpt
echo No cleanup for: $cam
echo '----- Space remaining on video drive'
df -h /mnt/video
sudo umount /mnt/video
echo Done!
echo Whoopsie! Total RC: $rcsum

Earring Laser Fixture

Cutting or engraving patterns on earrings should go more smoothly with a fixture:

Earring fixture - demo install
Earring fixture – demo install

That’s a serving suggestion, using the Biohazard test pieces, which also helped align the top and bottom layers while gluing:

Earring fixture - clamping
Earring fixture – clamping

That used all my little clamps: obviously I need more!

The bottom layer (red) is MDF for strength and the top layer (orange) is chipboard because that’s all it needs:

Earring fixture - LB layout
Earring fixture – LB layout

The little tab along the top ensures alignment using the jump ring cutout. The central hole will let me cut through the earring, should that be necessary.

The two strips over on the left get glued on the bottom, spaced to align along one of the aluminum knife blade rails, as with the craft stick fixture. With that lined up, any two of the four targets will serve to align the template with the fixture using LightBurn’s Print-and-Cut tool, as with the craft stick template.

Now, to make some smoke!

The LightBurn SVG layout as a GitHub Gist:

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Going About Their Daily Affairs

The fox caught what looks like a small groundhog for supper:

IM_00307 - Fox with supper - 2023-05-25
IM_00307 – Fox with supper – 2023-05-25

The tom turkeys have been forming and re-forming their groups:

IM_00178 - Turkey parade - 2023-05-24
IM_00178 – Turkey parade – 2023-05-24

The gray cat may have spotted breakfast out there in the yard:

IM_00112 - Gray Cat - 2023-05-23
IM_00112 – Gray Cat – 2023-05-23

We haven’t seen a raccoon stand up like this before, so something must be very interesting out there:

IM_00089 - Standing raccoon - 2023-05-27
IM_00089 – Standing raccoon – 2023-05-27

Off to its far right, Mary had fertilized a new pepper planting, which evidently smelled good enough to motivate vigorous digging. None of the plants sustained damage, despite being tossed around, but dexterous paws were surely involved!

Punching the Exercise Ticket

An unfortunate confluence of weather, schedule, and enthusiasm led to mowing all the yard in one session:

Mowing pattern - 2023-05-27
Mowing pattern – 2023-05-27

I managed to remember to pause the tracker during a break in the middle, so it’s really just shy of three wall-clock hours from start to finish. It’s amazing how much work you (well, I) can get out of 100 mg of caffeine.

Despite what you see here, the path on what’s euphemistically called “our lawn” show a much more organized solution to the problem of covering our property with non-overlapping foot-and-a-half stripes. As with my leaf-shredding track, I neither venture into the road nor mow the neighboring yards.

Bonus: slept like a stone that night …

Biohazard Earrings

More desk clearing revealed a sketch for another trinket:

Biohazard symbol
Biohazard symbol

That’s built directly from the original specs to get the spacing and symmetries correct. The freebies I could find all suffered from various degrees of bad design & layout.

A chipboard coaster provided some reassurance:

Biohazard coaster
Biohazard coaster

Shrunken down to 25 mm OD, the tips become vanishingly small:

Biohazard earring - vinyl sample
Biohazard earring – vinyl sample

It’s the same laser-safe polyurethane vinyl as the SD card reader, this time applied to 3 mm black acrylic. The “gold” ring is just parked in place, as this one wasn’t presentation-quality.

Contrary to the usual transfer-tape method of applying PSA vinyl, I stuck the sheet to the acrylic before cutting, then weeded it directly off the acrylic:

Biohazard earring - vinyl weeding
Biohazard earring – vinyl weeding

Kiss-cutting the vinyl with dot mode ate into the acrylic, but the soon-to-be-weeded areas protected the surroundings and the result came out looking pretty good. To me, anyhow.

Flushed with success, I tried some almost certainly not laser safe glow-in-the-dark tape:

Biohazard earring - GITD weeding fail
Biohazard earring – GITD weeding fail

The mess in the upper left is the tape’s double-sided adhesive intended to hold the glowy layer in place forever. Of course it weeded poorly!

Seen in its natural environment, however, weeding may not be necessary:

Biohazard earring - GITD tape glow
Biohazard earring – GITD tape glow

Engraving the rebated rim leaves quite a bit of debris & scorch marks around the perimeter. A mask layer atop the GITD tape seems like a Good Idea™.

The LightBurn SVG layout as a GitHub Gist:

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Engraved Popsicle Sticks

Having found a handful of popsicle sticks on my desk, I had to finish this up:

Popsicle stick markers - engraving
Popsicle stick markers – engraving

The fixture has the same layout as the craft stick version, sized to fit the smaller sticks. They’re a bit thicker than the chipboard sheet, but match up well enough for the purpose.

Even though the sticks don’t have much room for cutout letters, I had to try it anyway:

Popsicle stick markers - finished
Popsicle stick markers – finished

Aligning the template to the fixture uses LightBurn’s Print-and-Cut tool, which seems easier than nailing the fixture to the laser platform.

I suppose if they ever make actual popsicles with wood handles, they can tell who gets which one.

For whatever it’s worth, the larger craft stick markers in the garden remain in good shape.