Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.
Tag: Improvements
Making the world a better place, one piece at a time
The trap boxes come in 7 quart and 3.5 quart sizes, although we expect either will comfortably accommodate a single vole.
They’re made of polypropylene plastic eminently suited for laser cuttery, so I borrowed the holes from the cardboard box setup:
Vole Box – hole cutting
The clamps on the knife bars held the angle block and boxes in pretty much the same position, so I didn’t realign anything after figuring out a pair of magnets would hold the lid to the angle:
Vole Box – lid fixture magnets
The box side is slightly sloped, so I probably should have angled the block to tilt the lid, but this isn’t a precision job:
Vole Box – lid fixture
The white smudges on the lid come from vaporized polypropylene:
Vole Box – fume deposits
The body count thus far is just one field mouse, but the season is yet young.
Trace the outlines and lay smooth curves around them with Inkscape:
Remote profiles – Inkscape curves
They needed a slight lengthening to account for the gauge pin diameter & deflection, but this isn’t a precision project.
Do the same with a scan of the front face, import the curves into OpenSCAD, extrude them, create a solid model of the remote from their mutual intersection, then add a cylinder to punch the depression for the steel plate:
Floor Lamp Remote Holder – solid model – bottom
The chonky model corners stick out too far compared to the stylin’ curves on the real remote, but I made the holder shorter than the remote specifically to avoid fussing with such details.
Floor Lamp Remote Holder – solid model – Show view
I briefly considered a circumferential clamp around the pipe before coming to my senses and making the pipe diameter 2 mm larger to accommodate a strip of double-sided foam tape.
The magnet gets a ferocious grip on the plate and I defined the result to be All Good™.
The OpenSCAD source code and SVG paths as a GitHub Gist:
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Paper sheets must lay flat in storage, but it’s impossible to extract a single sheet from a tall pile. So I converted some moving boxes into stackable trays, each holding about a ream of paper:
Letter Paper Tray – installed
The starting point is a stackable Universal Box from boxes.py, with one end reshaped to become a tray. One Home Depot Large moving box provides enough 4.0 mm cardboard to make four trays, with one side of the box left over for future projects:
Letter Paper Storage Racks – LightBurn screenshot
The gray rectangle in the middle is the LightBurn workspace grid representing the 700×500 mm laser platform:
Letter Paper Tray – laser cutting
Contrary to the screenshot, I move all the layouts off to the side leaving the platform grid clear. The blue rectangles around the layouts represent the various box flaps / sides, so I can:
Click a layout (which is grouped with the surrounding rectangle)
Click Ctrl-D to duplicate it
Hit P to put the duplicate at the middle of the platform grid
Lay the corresponding cardboard sheet from that box part on the platform
Align the layout with the cardboard using the camera
Fire The Laser
Copious application of hot melt glue gloms all the pieces together.
I added support beams under the cardboard bottom plate:
Letter Paper Tray – bottom
A 2 mm arch in the top of those strips puts a camber into the sheet to counteract the natural sag from carrying five pounds of paper. The four trays at the far left lack that camber and cry out for a Mulligan.
Some day the Basement Shop™ won’t smell like a campfire.
Making 200×200 mm layered paper “pictures” involved cutting the square blanks from 8½×11 Letter sheets, putting those blanks in a fixture to hold them flat, then cutting the layer patterns:
Layered Paper cutting fixture – in use
That worked well enough, but it occurred to me that I should cut the patterns directly into the Letter sheet, with a couple of tabs on each edge holding the square to the sheet so it didn’t fall free.
A cardboard prototype showed this would actually work, at least after I fixed the tab width to keep them from just evaporating:
Pyrotechnics – metallized paper fixture
The top and bottom strips of tape hold cardboard bars that flatten the slightly curled metallic paper. The tape on the sides holds the cardboard flat to the knife bars across the laser platform.
A few adjustments later, I had an MDF version:
Letter paper fixture – cardboard vs MDF
Which fits atop the bars even better:
Letter paper fixture – on knife bars
Cutting colored paper definitely makes for cheerful chaff!
The two bar magnets hold the fixture in place on the steel platform rim. The aluminum knife bars stand slightly proud of the steel, so there’s a 1.4 mm chipboard shim glued under the fixture to put it flat on the bars.
The opening is 10 mm smaller than the Letter sheet to support it all around. The recess is 1 mm larger than the sheet to allow for slight size variations, with an MDF ring flattening the sheet:
Letter paper fixture – sheet in place
The four targets in the corners correspond to targets in the LightBurn template suitable for Print and Cut alignment:
Letter sheet template – LightBurn layout
The alert reader will note the fixture targets on the MDF fixture sit juuuust slightly to the right of where they are in the template. It turns out the targets cannot be grouped with anything else (or even each other), because when you select a target on the template for Print and Cut the center of the selection must match the location of the physical target on the fixture.
However, it’s convenient to have the rest of the template grouped into a single lump, so it’s painfully easy to select and move only the template while leaving the targets behind. It seems while setting up to mark & cut the template, I managed to click-n-drag the group a few millimeters to the left.
I eventually used Print and Cut to align the template and target with the corners of that MDF frame, re-engrave the targets at the correct locations, and scribble over the misplaced targets. If I don’t tell anybody, they’ll never know.
We deployed low-effort vole trap boxes a few weeks ago, only to discover no voles checked in, most likely due to wintertime gardens consisting of bare earth. I had weighted the boxes with convenient rocks that pretty much crushed them flat during rainstorms.
So I converted a few dozen square feet of cardboard into better-looking boxes and transferred the traps:
Vole Finger Box – large
That one has a rat trap inside.
Smaller boxes hold mouse traps:
Vole Finger Box – small
Two pairs of 4 mm holes on the bottom flanges fit some spare irrigation pipe holddowns to, yes, hold them down, with those rotten planks keeping their lids in place.
They’re lightly customized “Electronics Boxes” held together by hot-melt glue. The jawbreaker URLs will get you started:
The object of the game being to tilt the LED strip lights at (maybe) 30° to put more light higher on the wall and further out on the ceiling, with the overriding constraint of no visible holes. Given their eventual home atop the window moulding along the front wall of the Living Sewing Room, these seemed adequate:
LED Bar Lamp Mount – solid model
The hole on the angled part fits an M4 brass insert and the recessed holes capture the washer-like head of a sharp-point lath screw.
Two pairs applied to the lights sitting atop the Fabric Cabinets served to verify the fit:
LED strip light – moulding mount – on cabinet
They’re held firmly by the aluminum extrusion and don’t need a bigger footprint to remain stable.
So I made another six, stuck on ⅞ inch strips of aluminized Mylar (cut from a bag in much better condition), and drilled holes where they can’t be seen:
LED strip light – moulding mount – installed
It’s almost too bright in there with 3 × 40 W of LED lights washing the wall and ceiling:
LED strip light – moulding mount – lit
I don’t like the cold 6000 K color temperature, but Mary doesn’t mind it. They fill the Sewing Table with shadowless / glareless light, although that kind of light makes the place look like a store.
I think moving the strip lower and away from the wall could hide the entire mount from view.
Contrary to what I expected, the Mylar reflectors must be at least an inch tall to avoid Baily’s Beads seen from across the room:
LED strip light – short reflector
With all that in mind, we’ll run these for a while to shake out any other improvements.
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This is a quick-and-ugly test to see how well aluminized Mylar will work as a reflective shade for some LED light bars eventually washing the Living / Sewing room ceiling with enough light to brighten the Sewing Table:
LED strip light – Mylar reflector – ugly fit
The key question: how well adhesive adheres Mylar to the pleasantly warm aluminum extrusion serving as the heatsink for 40 W of LEDs:
LED strip light – Mylar reflector – adhesive strips
Perhaps surprisingly, those ½ inch strips come from an A4 sheet by way of a paper cutter.
The LED bars will be directly visible, so bouncing the direct light against the wall reduces glare and puts it to good use.
The Mylar strips are 1 inch wide, cut with a utility knife against a straightedge, although ⅞ inch seems adequate. The last LED over on the right sits at the endcap, so I will (try to) tuck the Mylar ends under the caps for a cleaner fit.
The bars have two 4 foot strips of LEDs in series, with a lump of circuitry buried in the aluminum extrusion that seems be a bridge rectifier and a small electrolytic capacitor. There’s not nearly enough capacitance to knock down the 120 Hz flicker and I have an uneasy expectation of stroboscopic effects on the sewing machines.
The Smell of Molten Projects in the Morning 
