Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
I’ve been doing some amateur surveying in preparation for the long-awaited driveway paving project, just to see where the property boundaries might be, and this Bosch GLR225 laser rangefinder makes it wonderfully easy to measure distances:
Bosch GLR225 Laser Rangefinder
It’s good up to 230 feet = 70 meters, which means you can measure a sizable chunk of property in one shot. It reads down to 2 inches with 1/16 inch accuracy / resolution (call it 50 mm and 1.5 mm), so one could use it for setups in the shop. It can solve right triangles, which means you can measure distances with an obstruction in the middle, and has a few other tricks. Other rangefinders evidently have more tricks, but I favor writing direct measurements on paper and making computations based those values, rather than using mysterious results direct from the field that can’t be easily verified at the desk.
I tried measuring the nominal 212 foot distance to the Hudson River from the center of the Walkway, but it reported an error. Most likely, specular reflections from water don’t work well, at least not at that distance.
You can buy retroreflective targets, but the Basement Laboratory Warehouse Wing disgorged what looks like roadside border markers, pre-bent into a useful shape:
Laser targets – normal
Seen by reflected light, they’re much more impressive:
Laser targets – flash
They came with the house, so I don’t know their provenance. What I do know is that I can’t hold the rangefinder steady enough to keep the spot on the target at much more than 100 feet. If I get around to doing much more surveying, I must conjure up a tripod mount; the base has a 1/4-20 socket in an awkward location and can measure relative to the screw centerline. Perhaps a rifle stock with a spotting scope would be handy, too, although I’d certainly acquire another black spot on my record.
If you were going to use it in the shop, you’d want a rotating pivot aligned at the intersection of the tripod socket and sensor port to get a known center point.
You can get one on eBay at a substantial discount, of course…
Back in December 2007 I printed four copies of a picture on various papers with the Canon S630 and hung them on a floor joist over my workbench, directly below a fluorescent shop light. Having just hung those screwdrivers where the pictures used to be, it’s time to see what’s happened.
The pictures, scanned on an HP C7670A (aka Scanjet 6300C) against the neutral gray of the ADF platen:
Inkjet Colors vs. Paper vs. Time
The papers, clockwise from lower left:
Glossy
Matte
Plain
Inkjet
While the scanner isn’t renown for its color fidelity, the overall results look about right; the platen really is that shade of gray and the upper-right picture has a sickly green hue.
The faded edges along the right side of the left-hand image show where the adjacent sheet overlapped: the colors didn’t fade nearly as much. The small rectangles on the lower left corners of the right-hand images show where I put clothes pins to keep the sheets from curling.
All of the images have a blue overtone; the magenta dye fades out with exposure to UV from the fluorescent fixture.
As you’d expect, the glossy paper looks best, with very crisp detail. The inkjet paper is next, followed by the matte, and the plain paper in the upper right obviously doesn’t support the ink well at all.
Of course, after five years I no longer have any of those papers and am using entirely different ink…
To show that the scanner really does matter, here’s the same set of images from a Canon LiDE 30:
Inkjet Colors – Canon LiDE30
In both cases. that’s without any color correction / gamma compensation / whatever. I should fish out my scanner calibration targets and go through the whole color calibration dance again; with any luck, the Linux color management infrastructure will be less inadequate by now.
Our Larval Engineer may have a commission to fit her Speed-Sensing Ground Effect Lighting controller to another longboard. To that end, the case now sports mouse ears to spread the force from the cooling ABS over more of the Kapton tape, in the hope the plastic won’t pull the tape off the aluminum build platform:
Longboard Case Solid Model – mouse ears
That view shows the bottom slice that will hold the battery, but the ears appear on all three layers.
The plunger is basically a pin that eventually deforms the top of the switch membrane. Tee’s DSC-H1 had an exposed switch, although this picture shows that membrane was still in reasonably good condition:
Shutter Switch Closeup
My DSC-H5 has a thin black protective disk atop the switch, but the disk wasn’t particularly protective and developed a dimple that held the contacts closed even with the shutter button released (which is why I’m tearing the camera apart in the first place):
DSC-H5 Shutter Switch – dimpled protector
The C-clip around the plunger is now plastic, rather than metal, making it less likely to erode the thin plastic shaft. Pulling the clip off while holding the button down releases all the parts:
DSC-H5 Shutter Button – components
A few measurements from an intact shutter button, which may come in handy if you don’t have one:
DSC-H5 Shutter Button – plunger measurements
Mount three-jaw chuck on the Sherline table, laser-align chuck to spindle, grab shutter button by its shaft in a Jacobs chuck, grab shutter button in three-jaw chuck, release from Jacobs chuck:
DSC-H5 Shutter Button – in Sherline chuck
That’s not particularly precise, but it’s close enough for this purpose. I used manual jogging while testing the fit with a paper shim until all three jaws had the same clearance, then tightened the jaws.
I nicked the plunger at its base with a flush-cutting diagonal cutter, snapped off the plunger, and drilled a #56 hole through the button:
DSC-H5 Shutter Button – cap drilling
For reasons that made sense at the time, I repaired Tee’s DSC-H1 with a 1-72 brass screw. This time, I used an 0-80 (which I learned as ought-eighty, if you’re wondering about the indefinite article) screw and nut, because the screw head fit neatly into the bezel recess and I had a better idea of how to smooth out the threads.
This being plastic, I used the chuck to hold the tap in the proper alignment, then turned the tap through by finger pressure. This trial fit showed it worked:
DSC-H5 Shutter Button – 0-80 screw
Milling the nut down to a 2.8 mm cylinder required the usual manual CNC, with repeated iterations of this chunk of code in the MDI panel:
The 2.8 in the first line is the current OD and the 3.11 is the measured diameter of the 1/8 inch end mill. I started from a 5.0 mm OD that just kissed the nut, then worked inward by 0.2 mm at a time for very shallow 0.1 mm cuts:
DSC-H5 Shutter Button – 0-80 nut milling
The alert reader will notice, as did I, that the head isn’t quite centered: the cut trimmed the left side and left the right untouched, with an offset far larger than the centering error. As nearly as I can tell, the heads of those screws aren’t exactly centered on their threaded shafts, but the final result fixed that… and the overall error is a few tenths of a millimeter = maybe 10 mils, tops, so it’s no big deal.
With all that in hand, I applied a very very thin layer of epoxy to fill the threads below the now-cylindrical nut and convert the screw into a rod:
DSC-H5 Shutter Button – 0-80 plunger
My original intent was to use the screw head as-is atop the PET shield (per those instructions) on the switch membrane, but after reassembling enough of the camera to try that out, it didn’t work correctly: the half-pressed switch didn’t activate reliably before the full-pressed switch tripped.
The PET shield I used came from the side of a 1 liter soda bottle and turned out to be 0.27 mm thick:
DSC-H5 Shutter Switch – cover removed
I think the PET shield would work with the original plunger shape concentrating the force in the middle of the shield, but the nice flat screw head spreads the force out over a wider area. As a result, the force required to close the half-pressed switch contacts was roughly the same as that required to close the full-pressed contacts; remember the nub on the bottom of the black plastic tray concentrates the force in the middle of the full-pressed switch membrane.
So I removed the PET shield, added a dot of epoxy to fill the screw slot and compensate for the missing shield thickness, then filed a flat to make a nice pad:
DSC-H5 Shutter Button – epoxy on plunger
Reassembling the camera once more showed it worked exactly the way it should. In fact, the button seems more stable than the OEM version, probably because the slightly enlarged plunger shaft fits better in the bezel. Too bad about those scuffs on that nice shiny button dome, though:
DSC-H5 – repaired shutter button
Tossing the leftover parts seems entirely appropriate…
The half-pressed shutter switch position on my Sony DSC-H5 recently stopped working, which seems to be one of two common failures. The other, a broken switch shaft, happened to Tee’s camera, as described there, and I figured I should preemptively fix that while I was inside my camera.
This being a common failure, several folks have described how to dismantle the camera; I followed that guide’s English version.
The DSC-H5 differs slightly from that description. After I got the thing apart, it became obvious that there’s no need to remove the LCD panel, the main control board, and most of the ribbon cables if you have a Philips #0 or #00 screwdriver with a very thin shaft. There’s no way to describe this operation, so take it apart his way, then you’ll see what I mean: the guts can come out as one big lump.
In any event, all the camera controls eventually emerge from the body:
DSC-H5 Control Assembly
Looking back into the camera body reveals the bottom of the shutter button, captured by a static discharge contact and the gray plastic frame of the Focus / Break button caps:
DSC-H5 Shutter Button – interior view
Removing the pushbutton frame and pushing the left button bezel latch with a small flat-blade screwdriver extracts the shutter button; it falls out of the inverted body. This is one of the few intact DSC-H[1-9] shutter buttons you’ll ever see:
DSC-H5 Shutter Button – bottom view
Those rectangular protrusions lock into the slots in the black plastic cap that appears almost silver in this front view that shows the dimple in the switch membrane:
DSC-H5 Shutter Button Switch – depressed surface
You must remove the cap to release the flex PCB with the shutter switches. Two heat-staked pins retain the cap; a scalpel neatly slices off the melted plastic:
DSC-H5 Shutter Switch – cover removed
Nota bene: the DSC-H1 button bezel I repaired earlier does not have features that lock into the cap over the switch assembly, which means you can remove and replace it without disassembling the camera. You cannot remove or install the DSC-H5 button without taking the camera apart. I suppose this counts as a continuous product improvement, but …
The shutter switch has two parts:
The full-press switch that takes the picture (the white dot on the blue flex, shown above)
The half-press switch that triggers the focus & exposure is in a black plastic tray (seen edge-on above the white dot)
The bottom of the half-press tray has a small nub that activates the full-press switch, so the force required to activate the half-press switch must be considerably less than the force that activates the full-press switch. This turns out to be a critical part of the repair…
A closeup of the half-press switch with the protective cover sheet (the “damn confetti” of the disassembly instruction) and the dimple that held the contacts together with the button released:
DSC-H5 Shutter Switch – dimpled protector
A closeup of the switch through a snippet of PET plastic shows the switch membrane itself is in fine shape:
DSC-H5 Shutter Switch – cover removed
However, the new plastic shield did not work out well, for reasons having to do with the new button plunger. That’s the next step: rebuild the plunger…
Those aren’t alarm pushbuttons. These are alarm pushbuttons:
Submarine Albacore – alarm pushbuttons
They’re in the USS Albacore and obviously intended for use by someone in a hurry: the tactile shapes tell your fingers everything they need to know. If I understand the ship’s history, the Collision Alarm switch contacts closed only during tests, although they did have a close call with the sub towing the (unpowered) Albacore from the Philly boneyard to its final resting site.
According to the information we saw, the control board was refitted / replaced / redone to remove classified hardware, so the woodgrain Formica background may not be original. On the other hand, this was a sub intended for extensive experimentation, so maybe they used a cheap and easily machined material.
We stopped at Lowell MA to visit the New England Quilt Museum (photography prohibited) and the Boott Cotton Mills Museum (photography encouraged). The NPS, among others, managed to salvage the buildings and restore some of the machinery, to the extent that one room on one floor of one building has some running cotton mills:
Boott Cotton Mill Museum
A bit more detail:
Boott Cotton Mill Museum – line detail
The original mills used water power, as did much of New England’s industry, but moments after Watt worked the bugs out of that newfangled steam engine, water power was history. The museum uses a huge old electric motor, mounted on the ceiling, to drive the line shafts above the mills; the vibration shakes the entire building and they hand out ear plugs at the door, despite having only half a dozen mills operating at any time. The working environment, horrific though it was, attracted employees (largely young women) from across the region; it was a better deal than they had on the family farm.
Employees were, of course, prohibited from using cotton to plug their ears…
They sell the cloth in the museum shop and we’ll eventually have some kitchen towels.
The Smell of Molten Projects in the Morning 