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
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.
I’m finallyassembling the shelves for the last of the boxes cluttering the basement floor. Because the top of the wire shelf grid sits 4 mm below the top of the shelf rails, surely for some good reason, that pale strip is a 6 mm shim raising the grid just enough to let the boxes slide easily off without having to lift them over the rail.
It’s a pair of 3 mm thick MDF strips stuck together with tapeless sticky (a thin adhesive layer on backing paper), with the same adhesive holding the shim to the rail while I lay them down and plunk the shelf grid on top:
Wire Shelf Shim – side view
I made two sets of shims to fit the support rod spacing, with lengths carefully chosen to match two stacks from my Big Box o’ MDF Cutoffs, all 10 mm wide to fit the shelf rails:
Wire Shelf Shim – laser cutting
Admittedly, not all of the neatly rounded corners came through, due to slight variations in MDF sizing / Print-and-Cut alignment / whatever, but it’s a nearly zero waste way to turn stock into strips.
Each shelf needs 14 shims = 28 strips and I’m here to tell you if I had to bandsaw 140 little strips for each of three sets of shelves, well, I:
Probably wouldn’t ever get around to making them
Definitely would grumble about lifting those boxes, forever
The L4-L5 pair are part of an extensive human anatomic model locating all the pieces at their proper coordinates, so these two hovered about 800 mm above the XY plane. I ran them through the Grid:Tool mesh editor to center them at the XY origin, then put the bottom-most point at Z=0.
Rotating them individually in PrusaSlicer and painting only the most essential support got them to this state:
L4 L5 vertebrae – PrusaSlicer
Each one take about three hours, so I ran them individually to reduce surface blemishes and maximize the likelihood of happy outcomes. Worked like a champ.
The retina-burn orange disk is not anatomically correct, because the InterWebz apparently does not have a model for spinal cartilage:
L4 L5 vertebrae – assembled – disk detail
Instead, it’s a rounded cylinder resized into an oval, with its top and bottom surfaces formed by subtracting the vertebrae:
L4 L5 vertebrae disk – solid model
The OpenSCAD code doing the heavy lifting:
// Disk between L4 and L5 vertebrae
// Ed Nisley - KE4ZNU
// 2025-03-07
Layout = "Show"; // [Show,Build]
include <BOSL2/std.scad>
module Disk() {
color("Red")
difference() {
translate([9,-18,36])
rotate(110)
resize([33,45])
cyl(d=50,h=14,$fn=48,rounding=7,anchor=BOTTOM);
import("../Spine/human-spinal-column-including-cervical-thoracic-and-lumbar-vertebra-model_files/L4 L5 vertebrae stacked.stl",
convexity=10);
}
}
if (Layout == "Show") {
Disk();
color("White",0.3)
import("../Spine/human-spinal-column-including-cervical-thoracic-and-lumbar-vertebra-model_files/L4 L5 vertebrae stacked.stl",
convexity=10);
}
if (Layout == "Build") {
Disk();
}
All of the magic numbers come from eyeballometric measurement & successive approximation.
The Build layout left the disk floating in space, whereupon I used PrusaSlicer to reorient it edge-downward on the platform with painted-on support for minimal distortion:
L4 L5 vertebrae disk – PrusaSlicer
Two dots of E6000+ adhesive hold everything together.
All in all, it was a useful distraction. I’ve been vertically polarized for the last five days and it’s good to be … back.
Both of those “projects”, which may be too grand a term, went from “I need a thing” to having one in hand over the course of a few minutes yesterday. Neither required a great deal of thought, having previously worked out the proper speed / power settings to cut 3 mm MDF and 1 mm cork.
Other folks may lead you to believe lasers are all about fancy artwork and elaborate finished products. Being the type of guy who mostly fixes things, I’d say lasers are all about making small and generally simple parts, when and where they’re needed, to solve a problem nobody else has.
Perhaps I should devote more attention to using fancy wood with a hand-rubbed wax finish, but MDF fills my simple needs.
With a laser and a 3D printer, shop tools have definitely improved since the Bad Old Days!
The Handi-Quilter HQ Sixteen rides on two tracks along the 11 foot length of the table, with an unsupported 8 foot span between the legs on each end:
HQ Sixteen – remounted handlebars in use
Contemporary versions of the table have support struts in the middle that our OG version lacks and, as a result, our table had a distinct sag in the middle. During the course of aligning the table top into a plane surface with tapered wood shims, I discovered the floor was half an inch out of level between the table legs.
Now that the whole thing has settled into place, I measured the shim thicknesses and made tidy blocks to replace them:
HQ Sixteen – table shims – finished
The OpenSCAD code has an array with the thickness and the number of blocks:
Yes, I call them “blocks” here and wrote “shims” in the code. A foolish consistency, etc.
The model is a chamfered block with a chunk removed to leave a tongue of the appropriate thickness:
HQ Sixteen – table shims – solid model
Building them with the label against the platform produces a nice nubbly surface:
HQ Sixteen – table shims – PrusaSlicer – bottom
The labels print first and look lonely out there by themselves:
HQ Sixteen – table shims – legends
The rest of the first layer fills in around the labels:
HQ Sixteen – table shims – first layer
Putting the labels on the bottom makes the wipe tower only two layers tall and eliminates filament changes above those layers. Those eight blocks still took a little over three hours, because there’s a lot of perimeter wrapped around not much interior.
Having had the foresight to draw a sketch showing where each block would go, I slid one next to its wood shim, yanked the shim out, and declared victory:
HQ Sixteen – table shims – installed
The tension rod welded under the table rail prevents even more sag, but the struts under the new version of the table show other folks were unhappy with the sag of this one. Another leg or two seems appropriate.
With the table leveled and the surface aligned, the HQ Sixteen glides easily in all directions. The result isn’t perfect and Mary keeps the anchor block at hand, but the machine now displays much less enthusiasm for rolling toward the middle of the table.
The OpenSCAD source code as a GitHub Gist:
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Installing the new ball-mount laser stylus on the HQ Sixteen’s electronics pod required nothing more than two strips of good foam tape:
HQ Sixteen – Stylus Laser – installed – overview
In actual use, you would:
Lay down a “pantograph” pattern on a paper strip along the rear track under the machine’s carriage
Position the needle at the appropriate spot on the quilt
Aim the laser at the corresponding point on the pattern
Start the machine!
Move the laser spot along the pattern while the machine stitches that pattern in the quilt
Mary thinks free-motion quilting is easier and I’m not in a position to argue the point.
Anyhow, the key feature of my ball mount is that it’s completely out of the way:
HQ Sixteen – Stylus Laser – installed – front
Which looks comfortingly like the original solid model:
HQ Sixteen – Stylus Laser Mount – solid model – show
Minus the vivid red death ray and pew! pew! pew!
Power comes from a barrel jack in the back intended for the original stylus laser; all small lasers, unless otherwise noted, run from 5 VDC. The jack is 3.5×1.3 mm, but the Drawer o’ Weird Barrel Plugs disgorged a matching right-angle plug. Unsurprisingly, such things are readily available these days.
Splice the laser leads to the plug and cover the evidence with a braided loom + heatshrink tubing:
HQ Sixteen – Stylus Laser – installed – rear
I considered a switch, but the anticipated low duty cycle suggested just unplugging it, so that’s that.
Start by conjuring a lathe chuck fixture for a 1 inch ball from my OpenSCAD model and printing it in PETG-CF:
HQ Sixteen – Stylus Laser – center drilling
Run a few drills through the ball up to 15/32 inch = 0.469 inch = 11.9 mm:
HQ Sixteen – Stylus Laser – final drilling
Which looks terrifying and was no big deal.
The laser module didn’t quite fit until I peeled off the label, as setting up a boring bar seemed like too much hassle for too little gain. The ball is slick polypropylene and the laser module is chromed plastic, which means there’s not much friction involved and a stiff fit is a Good Thing™.
I did not realize the hazy white patches barely visible inside the ball were voids / bubbles:
HQ Sixteen – Stylus Laser – drilled ball
Next time I’ll (try to) orient the patches toward the tailstock in hopes of simply drilling through them to leave solid plastic around the rim.
Ramming the laser in place makes it look like it grew there;
HQ Sixteen – Stylus Laser – laser test fit
The alert reader will note the lens projects a line, due to my not ordering any dot modules back when I got a bunch of these things. After all, who wants a plain dot when you can light up a line or even a crosshair?
The Smell of Molten Projects in the Morning 