Posts Tagged Repairs
My Sony HDR-AS30V is an action camera, but requires an external case / frame to mount it on anything. Here’s the camera inside its AKA-SF1 Skeleton Frame atop my helmet:
Four 1 mm tall ramps on the inside of the black base (the part just above the yellow sled) snap into 2.6 mm square sockets in the skeleton frame surrounding the camera. For an unknown reason(s) that surely involves applying forces I don’t remember, an opposing pair of those ramps broke off, leaving the other pair to loosely hold one end of the camera in place.
In this picture, the left ramps (one visible) are missing, leaving a square-ish gray scar that’s nearly indistinguishable from the reflection on the intact ramp on the right:
Surprisingly, the round head of a brass 0-80 machine screw fits neatly inside the square socket on the frame; they’re a bit more than 1 mm deep. The approach ramps visible below the sockets guide the latches on the base:
So I figured I could just shave off the remaining two latch ramps, drill four holes at the proper spots, and replace the plastic ramps with metal screws.
I clamped the skeleton frame to the Sherline’s tooling plate, aligned it parallel to the X axis, put the laser spot dead center in the square socket, then snapped the base onto the frame. The laser spot shows where the drill will hit:
A carbide drill did the honors:
That’s a #55 = 0.0520 hole for 50% thread, rather than the proper 3/64 = 0.0469 hole for 75% thread, because that’s the closest short carbide drill I had; an ordinary steel twist drill, even in the screw-machine length I use on the Sherline, would probably scamper away. The hole isn’t quite on the sloped bottom edge of the base, but it’s pretty close.
The first hole didn’t emerge quite in the center of its ramp scar:
Which made sense after I thought about it: the ramp tapers to nothing in the direction of the offset, so the hole actually was in the middle of the matching socket.
Threading the holes required nothing more than finger-spinning an 0-80 tap:
The feeble thread engagement didn’t matter, because those mysterious tabs-with-slots (possibly for tie-down strings?) just above the holes were a perfect fit for 0-80 brass nuts:
The screw heads extend into the sockets, hold the frame solidly in the base, and make it impossible to pull out. Although the frame still slides / snaps into the base, that seems like it will wear out the sockets in fairly short order, so I’ll unlatch the frame (with the yellow slide latch on top), open it up, ease it into position, and then latch it in place. That was the only way to remove it from the original latches, so it’s not a big deal.
I should add a drop of epoxy to each of those nuts and perhaps fill the screw slots with epoxy to keep them from abrading the plastic inside the sockets. Maybe a dab of epoxy on the heads, followed by latching the frame in place, would form four square pegs to exactly fill the sockets.
This was a straightforward repair that should not have been necessary…
The elevation tension adjustment on both our bike helmet mirror mounts have become a bit sloppy. That’s no surprise, because I expected the tiny set screw in the tiny square hole near the top to eventually wear a depression in the ABS plastic arc upon which it bears:
So I got to do something I planned pretty much from the beginning of the project: cut a snippet of phosphor bronze spring stock to go between the Elevation mount and the arc, then bend the ends bent inward so they don’t slash an errant fingertip:
Slipped in place, the ends look like they stick out anyway, but they’re really just about flush:
Tightening the set screw pushes the strip against the arc, where it provides enough resistance to prevent slipping and enough smoothness for easy adjustment.
While I had the mounts up on the repair stand, I unscrewed the mirror shaft and snugged up the Azimuth pivot screw by a micro-smidgen to tighten that motion.
Four years ago, those ABS parts popped off the much-hacked Thing-O-Matic’s platform. The M2 produces somewhat better-looking results, but that yellow plastic has a certain charm…
Plotters date back to the days before companies started using DRM to protect their monopoly positions, so refilling plotter pens requires little more than prying out the plug and squirting in more ink. Refilling the disposable liquid ink pens and the green ceramic pen suggested this would work.
I shaved down the side of a Genuine HP pen to find out why the plug didn’t pop out. It turns out the plug has a long and aggressively ribbed profile to ensure a gas-tight fit:
The easiest way to refill those is to drill an off-center 1/16 inch hole in the plug, then inject ink into the sponge with a syringe and blunt needle (and bulk ink!) from an inkjet cartridge refill kit. Angling the needle through the sponge close to the pen wall, then filling slowly, loads the sponge from the bottom up and expels the air along the way.
Inmac pens have a shallow plug, more of a flat cap, that pries out with zero drama:
Dripping the ink atop the sponge seems to work well, although that sponge is definitely over-filled.
Inmac caps push back in place with zero drama.
The pens have fiber nibs with vent channels along their sides that allow air into the reservoir, so overfilling the sponge nets you a mess when you take the cap off the nib: those same channels allow excess ink to run from the reservoir around the nib, without (much to my surprise) wetting the fiber tip.
About 0.2 ml of ink fills the reservoir to saturation, 0.1 ml leaves it wet, and 0.05 ml seems to work well. The 1.0 ml syringes I’m using require about 0.05 ml to fill the (blunt!) needle shaft & hub, plus the syringe tip below the 0.0 ml index, so measuring the ink by drops might make practical sense.
The old physician’s trick of expelling that air by inverting the syringe and pressing the plunger until liquid squirts from the needle is so not happening…
I’ve had zero success refilling fossilized pens, probably because the OEM ink slowly evaporating from the nib clogs all the gaps between the fibers with pigment or coagulated solvent. Preemptively refilling good pens when they first show signs of running dry generally works well.
Given the number of New Old Stock pens I have that are still in their original wrappers, this is more of a “Does it work?” exercise than a necessity.
But, y’know, maybe becoming the last plotter pen refiller on the planet will be my ticket to fame & fortune! For sure, we’ve all seen over-hyped Internet startups with worse business plans and (the admittedly few) typewriter repair shops occupy a stable niche.
As I rolled into the Stewart’s Shop on a milk-and-eggs run, a plume of smoke spiraled out of the cigarette butt station near the door, way off on the left side:
A closer look:
By the time I unhitched myself from the bike and reached the door, two smoke jets squirted from the top and a pall of breathtakingly foul smoke filled the parking lot. I mooched a big cup of water from the folks behind the counter and pulled off the container’s lid, which let in enough oxygen to ignite a full-up fire in the heap of cigarette packs, plastic wrappers, butts, lottery tickets, receipts, and other combustible junk atop the sand bucket in the base of the butt dump. Sprinkling the water over the blaze knocked it back; I replaced the lid and declared victory.
I always take a shower after returning home from a ride, but, this time, we also ran all my bike clothing through the washer right away.
Verily, it is written: Kissing a smoker is like licking an ashtray.
The ceramic-tip green pen I’ve been using finally ran dry and, having nothing to lose, I tried refilling it.
Grabbing the metal ferrule in the drill press chuck provided enough traction to twist / pull it off, revealing the pen nib assembly inside:
A pin vise provided enough traction to remove the nib, which had the expected fiber cylinder extending into the ink reservoir:
I injected 0.5 ml of yellow ink from my lifetime supply of bulk inkjet ink (*), then tried to inject 0.5 ml of cyan, which promptly overflowed. In retrospect, allowing a few minutes for the new ink to seep into whatever’s inside the reservoir would be prudent.
After wiping the mess off the pen and reassembling it in reverse order, it works just like new:
During the course of the first plot, the trace went from green to deep blue-green to a different green, which suggests the yellow ink took a while to make its presence known. No problem; whatever comes out of that tip is all good with me.
The stain around the rim of the pen body above the flange suggests a cap that might come off with sufficient persuasion. If it’s firmly fused to the flange, which would make perfect sense, injecting ink through a small hole drilled in the end might produce better results than ripping the nib out yet again.
(*) This leftover came from the never-sufficiently-to-be-damned HP2000C inkjet printer. ‘Nuff said.
The replacement for the second failed Sony SR-64UY MicroSD card arrived:
The previous cards were made in Korea, but this one came from Taiwan with a different serial number format:
The tiny letters on the front identify it as an SR-64UX, but I haven’t been able to find any definitive Sony source describing the various cards; their catalog page listing cards for digital still cameras may be as good as it gets. This one seems to have a higher read speed, for whatever little good that may do.
It stored and regurgitated the usual deluge of video files with no problem, which is only to be expected. This time around, I checked the MD5 sums, rather than unleashing
diff on the huge files:
cd /media/ed/9C33-6BBD/ for f in * ; do find /mnt/video/ -name $f | xargs md5sum $f ; done 11e31c9ba3befbef6dd3630bb68064d6 MAH00539.MP4 11e31c9ba3befbef6dd3630bb68064d6 /mnt/video/2015-07-05/MAH00539.MP4 ... snippage ...
It now sits in the fancy plastic display case that the HDR-AS30V camera came in until the previous replacement card fails.
Can you tell when our dehumidifier failed?
The step change in Week 22 shows when the replacement took over. After some poking around, Amazon Prime FTW.
The square-ish pulse starting in Week 26 marks a change from 55% RH to 60%RH and back again, to see how the front panel meter compares with the low end lab-grade hygrometer in the other side of the basement near the Hobo datalogger on the water inlet; they’re all off by a bit, but well within their expected tolerances. The 5% RH height of the step suggests a good match between their incremental calibrations.
It seems dehumidifiers last a few years, no matter which Brand Name you’ve decided to trust, so there’s not much point in developing a deep emotional attachment.
For the record, the old dehumidifier sported a GE label:
As it turns out, Electrolux bought Frigidaire a while ago, then absorbed GE’s appliances in 2014, so they’re all one big happy family now.