Long ago, I got Mary a cheap “desk calculator” with a vital function: it beeps cheerfully with each keypress. Nothing lasts forever and the aluminum dress panel around the keys has been gradually working its way loose.
So, we begin …
Gingerly remove the panel, un-bend and flatten it, lay it on the scanner, and cover with black paper:
Blow out the contrast, threshold the image, do a little touchup, and get a binary mask:
Import into LightBurn, trace and discard the image, do some shape optimization, add 0.2 mm to the height & width of one key, propagate those dimensions to other keys (Make same width and Make same height FTW), cut a paper prototype to verify the fit, iterate until it drops neatly into place, cut an adhesive sheet, then peel & stick:
The dress panel was held in place by what was once a quick-setting gooey glue that had long since fossilized. Although it gave up on the aluminum, it was not going to come off the calculator body without more struggle than seemed warranted.
So I stuck the new glue atop the old glue and hoped for the best. You can see traces of the old glue bead through the sheet:
Lay the dress panel in place, burnish between the rows & columns, and it looks about as good as it ever did:
If the adhesive sheet also gives up on the aluminum, I’ll try some fancy 3M 300LSE adhesive.
The WordPress AI image generator heard I like keys, so it spat out some keys for my keyboards:
The piano keys seem familiar, the thing in the middle looks eerily like a PDP-11 front panel, and … could that be a folding keyboard in the distance next to an 8-track player from a car dashboard?
The Smell of Molten Projects in the Morning 
