The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

Category: Machine Shop

Mechanical widgetry

Slotted Insects

Continuing the theme of Halloween decorations (and slots-n-tabs resizing), a Dragonfly took shape:

Dragonfly – assembled

It’s about a foot long, which makes one think of those prehistoric insects flying in dense, oxygen-rich air.

Of course, a Dragonfly needs prey, for which a Mosquito should suffice:

Mosquito – assembled

It’s about five inches from needle tip to tail and would certainly put up a stiff fight.

They’re both made from chipboard, with original model slot sizing being Close Enough that I could just resize the whole thing to fit the available sheets.

2024-08-07
Tour Easy: Anker 20K V2 USB Power Bank

After five years, it’s time to replace the Anker 13000 mA·hr USB power banks / chargers I used with the M20 cameras and then the C100 cameras:

SJCAM M20 Mount – Tour Easy side view

The Anker 325 20K V2 power bank is considerably chunkier, as befits its 20,000 mA·hr cell capacity (although the fine print says 12,500 mA·hr output):

Anker 20K V2 Power Bank – installed

The white tape stripe on the top marks the USB port on the end to reduce the fumbling involved in an out-of-sight socket. There’s also a USB-C port on that end for both charging the pack and powering other devices.

The new mounting cradle descends directly from the 13000 cradle:

Anker 325 20KV2 Power Bank – slicer preview

The model includes a projection of the battery on the XY plane for export to an SVG file suitable for laser-cutting an EVA foam pad to cushion the bumps.

The OpenSCAD source code as a GitHub Gist:

2024-08-05
Please Close The Gate Signs: One Year

They still look pretty good after a year:

Please Close The Gate – weathered acrylic – 2024-07-20

Which is to say: the orange acrylic hasn’t faded, the black paint’s still in place, and the gates seem to stay closed.

One might quibble about the missing wire snippet on the lower left corner, but on the whole it doesn’t get much better than that …

2024-08-02
Tour Easy: PTT Button Replacement

After five years and one cleaning, the PTT button on Mary’s Tour Easy became increasingly intermittent, both failing to activate solidly and sticking closed (there being nothing quite like a hot mic during a good hill climb), so it’s time for an autopsy:

Failed PTT Switch – as extracted

The snap dome is much more scarred at the central contact:

Failed PTT Switch – snap plate

That might be a gold flash coating, but it’s pretty well worn away where it hits the central contact:

Failed PTT Switch – center contact

Those scratches surely happened during the previous cleaning pass, as I don’t see any way for the dome to create them.

The corner contact also shows some scuffs, along with a scar where the dome corner pivots:

Failed PTT Switch – edge contact

All in all, though, it worked quite well.

The replacement switch, also intended for indoor use on a keypad or some such device, pivots around the front edge and may be easier for her fingertip to activate:

New PTT Switch – installed

Hot melt glue seems vastly underrated for how wonderful a structural material it is.

If this one lasts five years, I’ll be perfectly happy.

2024-07-31
Laser Test Paper: Plant Label Testing

After a month outdoors, the (failed) flexible strip labels show signs of wear:

Laser test paper – 1 month weathering

The upper one has a coating of clear rattlecan paint and looks much the better for it. The lower one is bare, but also suffered greatly from being folded and tucked through itself, so it started in worse condition.

Perhaps the paper will work better when stuck to metal plant label stakes, although I suspect the adhesive sheet will fail first:

Laser test paper – small plant labels

Those are random names; Mary tells me the proper label format has the Latin nomenclature on the first line.

They’re now out on the patio for observation.

For whatever it’s worth, my fascination with this paper boils down to “it’s cheaper than Trolase” for applications not requiring archival quality and duration. If it lasts Long Enough, that’ll be Good Enough.

2024-07-26
Speaker Re-Foaming

Having recently promoted a pair of Radford Tri-Star 90 speakers to the Sewing Room, it was time to make them presentable:

Radford Tri-Star 90 speakers – taped grill

The original foam grill covering had disintegrated and left fossilized adhesive over the metal gridwork. Being not much for historic accuracy, I used double-sided duct tape (the blue barrier film peels off) and stuck some allegedly acoustic foam in place:

Radford Tri-Star 90 speakers – re-covered

The foam is a single sheet wrapped around three sides and, after some whittling, measured 19.5 inches tall and 19.25 inches wide. The width surely depends on how snugly it’s stretched, so allow a bit more and trim to fit.

Duct tape probably isn’t the right adhesive for the job, but we’ll see how long it lasts. I really did not want to use spray glue and doubted my ability to slobber liquid stickum without oopsing the cones.

The speakers sounded great back in the day and they definitely sound much better than my deflicted ears can hear now. Mary thinks they’re OK and that’s all that matters.

Patrick, wherever you are: thanks!

2024-07-25
COVID Buffer Extraction Tube vs. Acrylic Solvent Adhesive

This seemed like a good idea for dispensing small drops of acrylic solvent while gluing spiders together:

COVID test Buffer Extraction Tube – adhesive hack

It’s the Buffer Extraction Tube from a COVID-19 rapid test kit with a short brass tube jammed in its dropper tip. The longer brass tube let me suck that dose of solvent into the tube without any of the hassle required to pour the liquid from a big can into a little tube.

Tell me you didn’t save those things because you thought they didn’t look like they might come in handy for something.

Well, that turned out to be a Bad Idea™, because whatever plastic that tube is made out of cracks when exposed to the hellish mixture in SCIGRIP #3 solvent adhesive. The tube didn’t dissolve or melt, it just cracked when you (well, I) squeezed the sides.

My Box o’ Test Kits has a few other types of tubes, but I used a syringe from the inkjet refilling era and that worked OK.

2024-07-24