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.

Tag: Repairs

If it used to work, it can work again

Acrylic Engraving Dust

The MDF signs I made last year disintegrated pretty much on the expected schedule, so it’s time for something more durable:

Please Close The Gate – acrylic engraving

The idea is to engrave both sides of a 3 mm orange acrylic sheet, shoot it with rattlecan black paint, and declare victory. The second step awaits warmer weather, but at least I’m doing my part to prepare for the new gardening season.

Vaporizing that much acrylic produces a fair bit of debris:

Please Close The Gate – acrylic dust on laser head

Some dust / vapor accumulates / condenses on the honeycomb platform beyond the orange sign, but most of it gets through to the baffle on the exhaust duct:

Please Close The Gate – acrylic dust on exhaust port

A closer look shows it really does grow out from the perimeter of each hole:

Please Close The Gate – acrylic dust on exhaust port – detail

Now, if that doesn’t trip your trypophobia, nothing will …

A few passes with the trusty Electrolux vacuum’s dust brush brought the visible surfaces back to normal.

By now, the duct fan blades have surely layered on a good coating, too, which shall remain undisturbed until I find a better reason to open the duct.

2023-01-27
Ersatz Library Card: Fixed

Sharper eyes than mine pointed out I misspelled Poughkeepsie, so I took advantage of the opportunity to make the whole thing look better:

Library card tag – revised front

It turns out the low-surface-energy tape stuck like glue to the acrylic tag (because that’s what it’s designed for) and peeled right off the laminating film on the printed paper. So I stuck some ordinary adhesive film to the back of the new paper label, left its protective paper on the other side, cold laminated the film+paper, laser-cut the outline, peeled off the back side of the laminating film with the protective paper, and stuck the new adhesive to the LSE tape still on the tag.

I have no idea how well this will work out in the long term, what with two adhesive layers bonded to each other, but this whole thing is in the nature of an experiment.

2023-01-19
Eyeglass Spring Temple: Screw Hole Tweak

A screws in one of Mary’s eyeglasses unscrewed itself, but, miraculously, we found it and I retired to the shop.

Because the glasses have spring temples, the screw would not align no matter what force I applied to it:

Eyeglass spring temple – screw misalignment

So I just embiggened the hole until the available force did the trick:

Eyeglass spring temple – hole filing

Dots of Loctite worked into the threads should prevent that from happening again, but I’ve learned to never say never.

In retrospect, the temple pivots have an exposed slot that I think would allow jamming a block in place after pulling the spring-loaded pivot outward. Temple springs are impossibly stiff and I have previously failed to budge them in glasses without the slots, so I don’t know how well that might work.

Verily: If brute force isn’t working for you, then you’re not using enough of it.

2023-01-18
Kitchen Under-sink Cabinet Fan Incident

During the course of diagnosing and fixing the latest oven igniter failure, an unrelated series of events produced a flood under the kitchen sink and across the floor. After cleaning up the mess and determining the floor under the cabinet was merely damp, rather than wet, I drilled a hole suitable for another PC cooling fan from the Box o’ MostlyFans, installed the fan to pull air upward, and let it run for a couple of days while watching the humidity drop.

Fortunately, I had a hole saw exactly the right size for an 80 mm case fan:

Kitchen sink – fan cover plate

I will lay big money on a bet saying your kitchen cabinets don’t have Real Wood like that, nor are the interiors painted bold Chinese Red. This place really is a time capsule from 1955.

While the drying happened, I made a hole cover from 1.5 mm black acrylic and, there being no style points involved, rounded up a quartet of black-oxide self-drilling sheet metal screws to hold it in place.

Although it’s not obvious, there’s a layer of transparent plastic “shelf paper” in there. It covers the fan hole under the cover, so any future spills will have approximately the same difficulty reaching the floor as this one did.

The LightBurn layout produces both the fan cover and a template to mark the four screw holes around the fan opening:

Kitchen Sink Fan – LB layout

The blue tool layer lines serve as a guide for the rest of the cover layout; the matching orange square on the right marks the fan outline on the drill template as a quick size check.

No need for an SVG version, because now that you have the general idea, it’s easy to recreate it for your own fan.

2023-01-17
Kenmore 362.75581890 Oven: Another Igniter Bites The Dust
Our story so far:
- We installed a Kenmore gas range around the turn of the millennium
- 2006 – Oven burner tube & igniter replaced
- 2014 – Igniter replaced
Apparently igniters last about eight years, regardless of provenance, because the igniter just failed, with the usual symptoms of low current draw (about 2 A), failed ignition, and a faint smell of propane (well, mercaptan) before the safety valve kicked in:

Oven igniter – location

The new igniter, another low-buck Amazon offering, came with half a green plastic connector block that mated neatly with the existing half under the oven. Unfortunately, the new wires had female pins crimped on their ends, rather than the male pins required by the existing connector and the ceramic wire nuts I’d used to join the previous igniter to the OEM connector were non-removable.

So I trimmed the old wires to a usable length and applied the new ceramic wire nuts to the stubs:

Oven igniter – connector rewiring

Also as before, the new igniter measures 3 A, definitely below the low end of the valve’s 3.3 to 3.6 A range:

Oven igniter – current test

If this one lasts eight years, I won’t be the guy replacing it …
2023-01-16
Ersatz Library Card

The rather battered library card on the bottom has been rattling around on Mary’s keyring since late in the last millennium:

Library card tags – front

I made the one on the top as a replacement, because Mary wanted one, but the library no longer issues keyring cards these days.

The front surface was laid out in The GIMP, inkjet-printed on good paper, cold laminated, laser-cut with LightBurn’s Print-and-Cut process, then affixed to the acrylic tag with really good double-sided tape:

Adriance Card – LightBurn PnC layout

I cut and applied the tape after cutting the tag, but the next time around I’ll apply the tape to the stock and cut both together to improve the edge alignment.

The rear surface data is engraved directly into the same Trolase laminated acrylic I used for the plant tags:

Library card tags – rear

The smaller text uses dot mode and the bars & number are engraved:

Library card tag – detail

In retrospect, it’s painfully obvious the engraving passes should run parallel to the bars, rather than perpendicular to them.

The barcode uses Codabar encoding generated with a Codabar font. I scaled the graphic block slightly larger than the original in the hope of making it more readable.

I determined the start and stop characters by trial and error; for this card, they’re A and B. Which could, perhaps, stand for Arlington Branch, but might equally well be coincidence.

It worked perfectly on the first scan at the library counter and apparently went entirely unnoticed. I trust duplicating a library card does not constitute a federal offense.

For what should be obvious reasons, however, I’m not posting the LightBurn layout.

2023-01-04
Kitchen Knife Handle: Epoxy Patch

The black plastic-like substance molded around the tang of our daily driver kitchen knife crumbled away near the blade and eventually reached the point my thumb couldn’t stand it any more. Given the good results of the JB Weld coating on the cheese slicer (which is still going strong after four years), I chipped away the loose fragments on all sides, wire-brushed the crater with alcohol, and filled it with epoxy:

Kitchen knife handle – tape reforming

The Kapton tape bridges the solid part of the handle with the metal just behind the blade, holding the epoxy in more-or-less the right shape while it cured overnight. The other side looks much the same, which is why I couldn’t just let it sit out.

A few minutes with a file and wire wheel knocked back the high spots and left it looking much better than before, if a bit scuffed:

Kitchen knife handle – restored

The tang inside the molded shell is kinda-sorta cruciform, with an exposed rib along both sides. I think the plastic shrank around the tang in that gap between the ribs and the blade, where its lack of flexibility caused the cracks.

Neither a beautiful restoration nor a permanent fix, but it ought to last for a while. Similar cracks at the hilt end of the handle suggest more repairs lie in its future.

2022-12-30