Entries in Category Engineering and Inventions

Halloween Blinking Creature Eyes with LEDs, Arduino, and Laser Cutting

I made this blinking-creature-eyes lamp as a small gift for my father, who loves to scare neigborhood children during Halloween with a heavily decorated entryway. It's suitable for hiding in foliage, under a chair or couch, in a darkened window, etc. You can make one easily if you have a laser cutter and some way of making printed circuit boards, although a cardboard box with cutout eyes and some LED strip would work just fine as a quick way to get started.

PCB design in Eagle

This design was heavily determined by parts I happened to have on hand. The LEDs are high-brightness red 5mm devices; I bought a whole sack of these once from Electronics Goldmine (they made an appeance in the Goldfinger laser among other projects). Although I could have controlled the blinking with a 555 timer or similar circuit, I had some surplus Arduino Trinkets from Adafruit, and programmability is nice to have in a project like this one.

More 3D-Printed Bins, for Milwaukee Organizer Boxes

Many tool companies offer “jobsite organizer” boxes for small parts. Our local home stores carry DeWalt, Stanley, and Milwaukee products that are all on the same pattern: plastic briefcase-style box with a handle, a clear lid, and removable bins inside. Some of them can also be stacked and linked together for more storage. But since I'm not a contractor (the usual customers for these), I tend to acquire smaller quantities, but in a greater variety, of most classes of part: screws, plumbing fittings, crimp terminals, etc. So I usually want more resolution, i.e. more and smaller bins or dividers, than the organizer offers. For that, I have a 3D printer.

I selected the Milwaukee 48-22-8030, despite it being red, because it was the only one that had metal latch hardware, because the handle placement gives it the best ratio of internal to external volume, and because the Milwaukee organizers can be opened while linked to each other (the linking latches are only on the lids). In Onshape I designed a bin that would subdivide the smaller square bins diagonally.

Building a New Desktop PC After Nine Years

In the last month I assembled a new desktop computer for myself. This is my first significant upgrade in nine years, a timespan that my teenage self in the mid-nineties would have found unbelievable. At the time the upgrade cycle was something like three years long for anyone, even non-gamers, trying to keep up with typical software demands. In other words, the slowing of that cycle has allowed me to skip two major upgrades entirely, and I might even have kept going for a few more years except that my old video card was starting to fail with increasing frequency, and it wouldn't support DirectX 10. Although I'm not much of a gamer anymore, I had become aware of Planet Coaster, a sort of spiritual successor to the RollerCoaster Tycoon that consumed quite a lot of my time in the early 2000s, and obviously I had to play it.

AMD CPU after nine years, on the left, and the new motherboard, CPU cooler, RAM, and video card on the right.

3D-Printed Organizer Bins for Crimp Terminals

3D-printed bins, in black PLA, keep a larger variety of parts organized.

I recently needed to crimp some right-angle “flag”-style quick-disconnect terminals, which meant buying yet another crimp tool (turns out you can't use the same one you use for straight terminals) and yet more small parts, which of course have to be kept organized. To replace the various disconnected organizers I was using for this type of part I purchased a 15-inch Flambeau Merchant Box with lift-out tray, $19.99 at Orchard Supply.

I used the lift-out tray to acommodate a sheet of 1 1/8 inch Kaizen foam, a product I've used before to make drawer organizers for my office. Kaizen foam is made of layers that can be peeled from each other (but not as cleanly as you might want), so that you can draw an outline of a tool on the foam, cut straight down to the appropriate depth using a razor blade or other knife, and then hollow out the foam to that depth by digging with your fingers. This gave me a place for my crimp tools plus some room for future expansion.

Y-Axis Stop Upgrade for Prusa i3 3D Printer

The new part triggering the microswitch. Success!

Since day one of using Crystal Palace, my Reprapguru Prusa i3 V2 clone, I've been planning to fix the poor design of the y-axis stop switch. The Reprapguru design is annoying but marginally usable with careful adjustment and frequent human intervention, but after making a small bumper part on the 3D printer and screwing it to the bearing housing (all of forty minutes of effort) the problem is solved and I don't have to worry about it anymore. Not bad for a full year of irritation and procrastination!

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