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
They’re a pair of plumb bobs I’ve had forever, with ten feet of 100 pound Kevlar line in place of their original (and well-worn) string. The key parameter is the 1 mm diameter to fit the holes in the bobs, with the 20 pound working strength being grossly overqualified.
Because it’s braided line, the bobs no longer spin merrily when deployed, which is a major win.
They hibernate in pill bottles during their downtime, where the line doesn’t get nearly as tangled as you might imagine.
Admittedly, I don’t deploy plumb bobs all that often, but in recent months I have needed to know what was directly below something else often enough to remind me to get this done.
The WordPress AI image for this post is, as usual, disturbing:
Plumb Bobs – WP AI image
I like the perfectly rendered gibberish text. Is that a bizarre spade drill in the lower left? So many pills!
Although it may not be obvious from the picture, unlike my cardboard insert, the acrylic insert does not fill the tabletop hole to the immediate right of the machine:
Custom Inserts are U-shaped, designed to fit around all 3 sides of your sewing machine
Shortly after the insert arrived I hacked a temporary filler, for which no pictures survive, to keep pins / tools / whatever from falling to their doom. This turned out to be a blessing in disguise, because she wanted the machine positioned an inch to the right of its intended spot to leave enough space for a finger to reach the bobbin hatch latch.
I then promised to replace the ugly cardboard filler with a less awful acrylic filler and finally got it done:
Juki TL-2000Q in Gidget II table – insert filler
The stack of cardboard prototypes show iterative fit-and-finish improvements, with the odd shape on the top serving to measure the machine’s 25 mm corner radius by comparison with known circles.
The insert filler is made from smoked gray acrylic, because I have yet to unpack the acrylic stockpile and may not, in fact, have any clear 6 mm acrylic, so we’ll regard this as a final prototype pending further developments. It did, however, confirm the laser survived the move, which was pretty much the whole point.
The end of the machine is not a straight line. Part of the iteration was measuring the curve’s chord height to calculate the circle’s radius, which turned out to be 760 mm:
Juki Insert Filler – end chord circle
With that in hand, a few Boolean operations produced the filler shape:
Juki Insert Filler
A pair of silicone bumper feet stuck to the side of the Juki hold the left edge of the filler at the proper level.
For the record, the smoked acrylic came from a fragment of a Genuine IBM Printer stand I’ve had in the scrap pile since The Good Old Days:
By a quirk of fate, the Chamberlain garage door opener in our new house has the same “purple learn button” as the Sears opener in our old house, so I introduced it to our remotes and they work just fine.
I then replaced the four-button remote in my bike pack with a new single-button remote to reduce the dexterity required to hit the button:
Garage Opener – one button
Alas, the opener only responded when the remote was immediately outside the aluminum garage door. Checking the battery (because sometimes “new” does not mean what you think it means) reminded me we live in an age when hardware is free compared with bookkeeping:
Garage Opener – interior
Maybe the second button doesn’t work and this is how they monetize their QC reject pile?
I want the door to start moving when I’m at the end of the driveway, giving it enough time to get all the way up so I can bike right in. You can actually buy remote / extension antennas, although for fancier openers with SMA antenna connectors, but sometimes a little RF black magic will suffice:
Garage Opener – crude antenna director
The wavy wire hanging down from the opener’s rear panel is the original antenna, which might be kinda-sorta omnidirectional. The opener operates around 433 MHz= 69 cm, so a quarter-wave antenna will be 17 cm = 7 inch long; the (unbent) wire is maybe 10 inches long from the hole in the panel.
So I taped 11 inches of wire to the opener to form a very very crude Yagi-Uda antenna. It’s too long to be a director element, it’s about right (albeit in the wrong place) to be a reflector element, it might be neither.
What it does do is warp the antenna’s pattern just enough to let the remote reliably trigger the opener as I approach the end of the driveway.
Do not even begin to think about polarization mismatch from what looks like the tiny loop antenna on the remote’s PCB.
The gray angle brackets came from a long-gone (and sorely missed) radial arm saw, hacksawed to fit on either side of the central beam supporting the workbench top, and held with machine screws in those inserts. Yes, the rear bracket has only a single screw, but it doesn’t support much of a load and it’s not going anywhere.
With that in place, the drawers kicked around the basement for a few weeks and eventually ended up under a workbench that Came With The House™ and was likely built by the original owners half a century ago:
Desk keyboard tray – workbench drawers installed
The top is made of 2×6 boards, now topped with laminate planks (left over from when I re-floored the previous kitchen), so the 2×6 board in the middle holds the whole top together and is not removable. I conjured strips at the ends to support the drawer assembly:
Desk keyboard tray – workbench drawers end block
The strips came from the crate around the laser cutter, so they’re made of the cheapest Chinese plywood and entirely suitable for the purpose. The drawers hang from 1/4-20 bolts screwed into tee nuts recessed in the top surface of the strips, with the strips held by deck screws in those benchtop 2×6 planks.
Yeah, both of those are bodges, but they ought to work just fine.
The honeycomb platform in my OMTech laser cutter was secured by a pair of M4 screws passing through the surrounding frame into a pair of nuts requiring considerable contortion to install. As a result, I tended to use the screws as locating pins by just dropping them into the holes, which didn’t prevent me from jostling the honeycomb out of position on a few occasions.
With everything torn down as part of the move, I drilled out the holes in the frame and installed a pair of M4 rivnuts:
OMTech laser – Honeycomb screw rivnut
The scar around the hole in the honeycomb came from the factory; I have no idea what they were doing to cause that much wear.
Anyhow, installing the screws now requires zero contortionism and they locate the honeycomb much more securely.
I should conjure knobs for the top of the screws to eliminate the need for a hex key, although that’s definitely low on the task priority list.
The previous Basement Laboratory generally stayed above 60 °F = 15 °C, so I set the LightObject water chiller’s low-temperature alarm accordingly.
Having reached the point where I can set up the laser in its new home, I connected the chiller tubes, filled the reservoir with distilled water (and a squirt of algaecide), connected the alarm wiring, turned it on, and had the cool water trigger an alarm:
LightObject Laser chiller – low temp alarm
Which was relayed to the controller:
KT332N Diagnostic display – water protect active
Silencing the chiller’s alarm clears the error indicator in the controller, so it’s possible to Fire The Laser with too-cold water if necessary.
As with the previous icemaker chiller, plotting the water temperature as a function of time shows the pump adds some energy as it moves the water around the loop:
LightObject Q600 chiller – water heating
The gap in the data shows where I had a few other things to do, but the exponential rise is obvious. The chiller compressor starts at just over 21 °C and stops at just under 20 °C, so the exponential curve had gone about as far as it could go.
The numbers in the upper right of the plot give the weight of:
An empty water bottle
A full gallon bottle
The partially empty bottle used to top off the reservoir
How much water went into the chiller reservoir
The figures in the bottom mash the initial slope of that curve together with the weight of the water to find the 21 W required to heat the water at that rate, with a bank shot off British Thermal Units because why not.
A Kill-a-Watt meter shows the Q600 chiller draws 36 W with the pump running, which includes the controller and a column of blue LEDs behind the water level tube.
The pump (in the lower right) isn’t exactly water-cooled, but it’s not losing a lot of heat through that foam wrapper and maybe most of the heat really does come from the motor:
LightObject Laser chiller – right side internal view
The basement temperature will rise as Spring becomes Summer, so the chiller will start working right away, and it’ll definitely get more exercise when the laser starts cutting again.
A fairing fragment provided an excuse to practice plastic polishing:
Fairing polish – start
That’s from a EZR-SZ Zzipper fairing ridden about 2000 miles a year since 2001, so it’s spent far too much time in the sun and definitely not gotten all the finicky care it deserves. It’s tinted 60 mil polycarbonate, vacuum-molded into the bubble shape required to fit on a Tour Easy recumbent.
Fairing Flashlight Mount – Mary approaching
On the other paw, Karl Abbe (the guy behind Zzipper) says the typical fairing survives maybe half a decade, so it doesn’t owe us anything.
I applied all three bottles of Novus Plastic Polish in descending numeric order, using snippets of Official Polish Mates (which could be a Krakow escort service) with a vigorous circular motion, ending up with a reasonable result:
Fairing polish – transmission
I cut the smaller chunk from the fairing for comparison. It’s been washed to dislodge loose crud, but is otherwise as-ridden.
The fairing has deeper scratches than Novus can buff out, but removing the surface scuffs and haze definitely improves the clarity:
Fairing polish – clarity
The view from father away:
Fairing polish – clarity
Eks describes this sort of thing as a “Used Car Finish” = high polish over deep scratches:
Fairing polish – surface finish
All in all, a nice result from very little effort.
The Smell of Molten Projects in the Morning 