Archive for category Home Ec

Pot Lid Repair

For reasons not relevant here, we (temporarily) have a set of pots with glass lids. One of lids had a remarkable amount of crud between the glass and the trim ring under the knob, which turned out to be corrosion falling off the screw. Trying to remove the screw produced the expected result:

CKC Pot Lid - broken screw in handle

CKC Pot Lid – broken screw in handle

For whatever reason, they used an ordinary, not stainless, steel screw:

CKC Pot Lid - corroded screw

CKC Pot Lid – corroded screw

I figured I could mill the stub flat, drill out the remainder, install a new insert, and be done with it. The knob has a convex surface and, even though this looked stupid, I tried clamping it atop a wood pad:

CKC Pot Lid - precarious clamping

CKC Pot Lid – precarious clamping

Two gentle cutter passes convinced me it was, in fact, a lethally stupid setup.

Soooo, I poured some ShapeLock pellets into a defunct (and very small) loaf pan, melted them in near-boiling water, and pressed the knob into the middle, atop some stretchy film to prevent gluing the knob in place:

CKC Pot Lid - ShapeLock bedding

CKC Pot Lid – ShapeLock bedding

That’s eyeballometrically level, which is good enough, and the knob sits mechanically locked into the room-temperature plastic slab. Clamping everything down again makes for a much more secure operation:

CKC Pot Lid - clamped ShapeLock fixture

CKC Pot Lid – clamped ShapeLock fixture

A few minutes of manual milling exposes the original brass insert molded into the knob, with the steel screw firmly corroded in the middle:

CKC Pot Lid - screw stub milled flat

CKC Pot Lid – screw stub milled flat

Center-drill, drill small-medium-large, and eventually the entire insert vanishes in  a maelstrom of chips and dust:

CKC Pot Lid - OEM insert removed

CKC Pot Lid – OEM insert removed

Run a 10-32 stud into an insert, grab in drill chuck, dab JB Kwik around the knurls, press in place while everything’s still aligned in the Sherline, pause for curing, re-melt the ShapeLock, and the insert looks like it grew there:

CKC Pot Lid - new insert installed

CKC Pot Lid – new insert installed

Wonder to tell, a 1 inch 10-32 screw fit perfectly through the pot lid into the knob, with a dab of low-strength Loctite securing it. Reassemble everything in reverse order, and it’s all good:

CKC Pot Lid - repaired knob

CKC Pot Lid – repaired knob

Well, apart from those cracks. I decided I will not borrow trouble from the future: we’ll let those problems surface on their own and, if I’m still in the loop, I can fix them.


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Cast Iron Pan Seasoning: Round 3

After seasoning the pan after every meal for a few weeks, then not doing that for a few more weeks, its thick glaze began looking somewhat scuffed:

Cast Iron Pan - scuffed

Cast Iron Pan – scuffed

You may recognize some of those scars from the previous picture:

Wagner skillet - two weeks of use

Wagner skillet – two weeks of use

Perhaps the multi-layer seasoning was entirely too thick and prone to chipping; this time, I’ll try a thinner coating. Because it’s cast iron, the pan under the coating remains undamaged.

A few hours in a bucket of sodium carbonate solution with a battery charger driving a few amps through it removed most of the glaze and a few minutes with a sponge sanding block cleaned off the rest. Applying flaxseed oil and heating it to 400 °F on a regular burner (under close supervision!) produced a nice coating:

Cast Iron Pan - seasoned

Cast Iron Pan – seasoned

The single layer was way slick for veggies in the evening and handled the morning omelet with aplomb, so we’ll run with it until something interesting happens.

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Respooling Stainless Steel Thread: The Knack

The comments on my previous stainless-steel thread respooling attempt suggested that I was entirely too much of a sissy, so, when another empty spool appeared, I tried again with more vigor:

Stainless steel thread - second spool

Stainless steel thread – second spool

As before, I put the larger spool on the floor under the lathe and let the thread spill straight off the top toward the smaller spool. This time, I didn’t have a twist accumulating in the loose thread between the two spools:

  • Grab longer lengths of the loose thread
  • Absolutely no slippage between the fingers!
  • Put more tension on the thread at the takeup spool

As nearly as I can tell, the thread still has a slight twist coming off the larger spool, but grabbing longer lengths captures the twist and more tension lays it on the smaller spool. After cutting the thread, what was left had maybe three turns of twist, which was no big deal and obviously hadn’t accumulated.

Seems better: thanks for all the comments!



Under-cabinet Lamp Brackets: Close-fit Power Plug

Adding a little tab to the angled brackets prevents them from pivoting while you’re tightening the mounting screw into the brass insert:

Kitchen Light Bracket - angled lip - Slic3r preview

Kitchen Light Bracket – angled lip – Slic3r preview

The trick with those tabs is to chop ’em off halfway to the tip, because there’s no point trying to print a wedge that ends with a sharp edge:

Kitchen Light Bracket - angled - tab cutoff - solid model

Kitchen Light Bracket – angled – tab cutoff – solid model

Generating & positioning that block goes a little something like this:

           2*MountBlock[1] - LEDEndBlock[2]*sin(StripAngle),
           MountBlock[2]/2 + MountHeight - 0.5*LEDEndBlock[2]*cos(StripAngle)])

As a rule of thumb, there’s no point in fussing with smaller shapes when a big one will suffice…

This LED strip fits under the cabinet over the butcher block countertop next to the stove, which turns out to be Just Barely longer than the strip itself:

Under-cabinet light - cramped power plug

Under-cabinet light – cramped power plug

The OEM straight-on coaxial plug (near the bottom of the picture) attached to the wall wart cable obviously wouldn’t fit in the available space, so I gimmicked up a right-angle adapter by the simple expedient of shortening the solder lugs of a plug from the heap (which, admittedly, doesn’t quite fully seat in the socket), bending them sideways, soldering a pair of wires, heatshrinking appropriately, then coating wires + plug with JB Kwik epoxy. The other end of the wires gets a coaxial jack that miraculously fits the OEM plug, styled up with more heatshrink tubing. Not pretty, but nobody will ever see it.

Unlike the LED strip under the other cabinet, this IR proximity sensor doesn’t mind having a wood edge next to it and, thus, didn’t need a strip of tape to keep it happy.


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Under-cabinet Lamp Brackets: Angled Edition

The LED strip lights have a reasonably diffuse pattern with an on-axis bright area that puts more light on the rear of the counter than seems strictly necessary. Revising the original brackets to tilt the strips moves the bright patch half a foot forward:

Kitchen Light Bracket - angled - solid model

Kitchen Light Bracket – angled – solid model

For lack of anything smarter, the angle puts the diagonal of the LED strip on the level:

Kitchen Light Bracket - angled - Slic3r preview

Kitchen Light Bracket – angled – Slic3r preview

The translucent block represents the strip (double-thick and double-wide), with a peg punching a hole for the threaded brass insert.

Although the source code has an option to splice the middle blocks together, it can also build them separately:

Kitchen Light Bracket - angled - LED block

Kitchen Light Bracket – angled – LED block

Turns out they’re easier to assemble that way; screw ’em to the strips, then screw the strips to the cabinet.

I moved the deck screw holes to the other end of the block, thus putting the strips against the inside of the cabinet face. It turns out the IR sensor responds to the DC level of the reflected light, not short-term changes, which meant the reflection from the adjacent wood blinded it to anything waved below. Adding a strip of black electrical tape killed enough of the reflected light to solve that problem:


Under-cabinet light - IR sensor shield

Under-cabinet light – IR sensor shield

The tape isn’t quite as far off-center as it looks, but I’m glad nobody will ever see it …

The before-and-after light patterns, as viewed on B-size metric graph paper centered on the left-hand strip and aligned with the belly side of the countertop:

Under-cabinet light - straight vs angled patterns

Under-cabinet light – straight vs angled patterns

Those look pretty much the same, don’t they? So much for photography as evidence for anything.

The OpenSCAD source code as a GitHub Gist:



Quilt Blocks: Scan and Montage

Mary has been working on the Splendid Sampler project, with 56 completed blocks (*) stacked on her sewing table. We agreed that those blocks would make a nice background for our Christmas Letter, but the labor involved to photograph all the fabric squares and turn them into a page seemed daunting.

Turned out it wasn’t all that hard, at least after we eliminated all the photography and hand-editing.

The 6½x6½ inch blocks include a ¼ inch seam allowance on all sides and, Mary being fussy about such things, they’re all just about perfect. I taped a template around one block on the scanner glass:

Quilt block in scanner template

Quilt block in scanner template

Then set XSane to scan at 150 dpi and save sequentially numbered files, position a square scan area over the middle of the template, and turn off all the image enhancements to preserve a flat color balance.

With “picture taking” reduced to laying each square face-down on the glass, closing the lid, and clicking Scan, the scanner’s throughput became the limiting factor. She scanned the blocks in the order of their release, while tinkering the auto-incremented file number across the (few) gaps in her collection, to produce 56 files with unimaginative auto-generated names along the lines of Block 19.jpg, thusly:

Block 19

Block 19

The “square” images were 923×933 pixels, just slightly larger than the ideal finished size of 6 inch × 150 dpi = 900 pixel you’d expect, because we allowed a wee bit (call it 1/16 inch) on all sides to avoid cutting away the sharp points and, hey, I didn’t get the scan area exactly square.

With the files in hand, turning them into a single page background image requires a single Imagemagick incantation:

montage -verbose B*jpg -density 150 -geometry "171x173+0+0" -tile "7x" Page.jpg

I figured the -geometry value to fill the 8 inch page width at 150 dpi, which is good enough for a subdued background image: 8 inch × 150 dpi / 7 images = 171 pixels. Imagemagick preserves the aspect ratio of the incoming images during the resize, so, because these images are slightly higher than they are wide, the height must be slightly larger to avoid thin white borders in the unused space. With all that figured, you get a 1197×1384 output image.

Bumping the contrast makes the colors pop, even if they’re not quite photo-realistic:

Quilt block montage - contrast

Quilt block montage – contrast

I’ll lighten that image to make the Christmas Letter text (in the foreground, atop the “quilt”) readable, which is all in the nature of fine tuning.

She has 40-odd blocks to go before she can piece them together and begin quilting, with a few other projects remaining to be finished:

Mary quilting

Mary quilting

(*) She’s a bit behind the block schedule, having had a year of gardening, bicycling, and other quilting projects, plus whatever else happens around here. Not a problem, as we see it.


Under-cabinet Lamp Brackets

These blocky brackets hold a pair of LED light strips in the recess under our 1955-era kitchen cabinets, to let the light cover the entire counter:

Kitchen Light Bracket

Kitchen Light Bracket

The large holes are for drywall screws into the cabinet, the smaller ones for 2.5 mm SHCS holding the strips to the brackets. I drilled those little holes out and installed 4-40 brass inserts; this being a one-off installation, the source code doesn’t include that change.

There’s not much to see after they’re installed:

Under-cabinet light bracket - center joiner

Under-cabinet light bracket – center joiner

I’d hoped to swap the ends of the strip to power it from the right end, but the guts aren’t symmetric and you can’t just flip it end-for-end:

eShine LED Under-cabinet light - disassembled

eShine LED Under-cabinet light – disassembled

That’s an add-on unit without the IR proximity sensor circuitry and power switch, but with the same overall layout. You take it apart by pressing the obvious latch on one of the endcaps, then gently prying the plastic away from the aluminum extrusion, taking care not to wreck the coaxial socket. Reassemble in reverse order.

The OpenSCAD source code as a GitHub Gist:


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