Posts tagged "geometry"
18 posts
- Drain hair catchers, and the dome that tore in the slicer11 October 2026
The Drain Hair Catcher Generator makes a basket for a sink or bathtub drain or a slotted cover for a shower grate, and getting a perforated dome to survive an STL reload took three attempts.
- A T-handle for any hex key, and the key sizes behind it11 October 2026
How the Hex Key Handle Generator sizes a printed T-handle, screwdriver grip or lever sleeve from the number stamped on an L-shaped hex key, with the ISO 2936 and ASME B18.3 arm lengths it uses.
- A lens cap is a standard part, so I built a generator for it11 October 2026
The Lens Cap Generator turns the filter size printed on a lens into a push-in, slip-over or screw-in cap, with a strap holder and a fit-test ring, and here is the thread math behind it.
- Box dividers down to 3 mm, and the layout that needed 4.8 GB10 October 2026
The rugged box generator now builds divider compartments as narrow as 3 mm of free space, and a 400-cell layout that used to need 4.8 GB of memory now needs 0.45.
- "Cookie cutter walls, magnet pockets and keyholes: the rules a printable part checks while you type"30 September 2026
Every generator page on alpaco.it now checks your numbers before the preview asks the server. The rules that matter most for cookie cutters, miniature bases, wall hooks and spacers, and the broken preset that testing turned up.
- A mount for any box and a window vent insert, two generators I built from Reddit threads27 September 2026
The Device Mount and Rack Panel Generator holds a router, power brick or mini PC under a desk or in a 10 or 19 inch rack, and the Window Vent Insert Generator turns a window gap and a hose size into a panel cut into tiles for your bed.
- A 3D printed phone stand in five shapes and five patterns, with a third of the plastic27 September 2026
The phone stand generator now draws a folded ribbon, a curled arch, a truss frame, a charging ledge that floats above its base or the classic block, ripples it with waves, zigzag, ridges or facets, and still prints on its side with no support.
- Lithophane from a photo: thickness, size and light for a gift that actually glows25 September 2026
How a lithophane turns a photo into wall thickness, the numbers that decide whether it glows or looks like a grey slab, how big it can get, and how to print and light one before the holidays.
- Why fillets break at corners, and the dumb idea that fixed mine24 September 2026
A fillet on one edge that runs into a rounded corner is the hardest case in the CAD editor I am building. I spent a week patching corners, then threw the patches out and let each edge cut its own groove.
- Fillet or chamfer: which edges to round, which to cut at 45 degrees, and why the bottom one is different18 September 2026
The bottom edge takes a chamfer, the vertical corners take a fillet, inside corners take the biggest fillet you can afford, and the reason is the same every time: a printer builds upward in layers, so the shape of an edge decides what hangs over what.
- PET bottle thread sizes: PCO-1881, PCO-1810 and the 38 mm neck, and how to print a cap that fits17 September 2026
The three neck finishes on almost every plastic bottle, with the diameter, pitch and thread height of each, and the clearance a printed cap needs to screw onto a molded neck.
- "Printed threads: when they work and when to give up"6 September 2026
Three of my generators cut threads, from jar lids to M3 bolts, and each one taught me a different rule about pitch, depth and clearance. Here are the numbers that survived contact with plastic.
- Supports are a design smell30 August 2026
The 45 degree rule, bridges, chamfers and teardrops: most support material exists because the model asked for it. Here is how to design it away.
- Generator 35 is gears29 August 2026
The newest generator makes real involute gears, spur, helical or herringbone, with a matching pinion. Here is why gear teeth are not just bumps on a circle.
- How the clip latch stays shut26 August 2026
The rugged box closes with a printed clip that snaps onto four bumps. Getting it to stay shut, open on purpose and not fall in the grass took more versions than I want to admit.
- Gridfinity, or building someone else's standard24 August 2026
Most generators on this site invent their own dimensions. The Gridfinity one is not allowed to, and matching a community standard to a tenth of a millimetre turned out to be its own kind of work.
- A vase that cannot fail in vase mode24 August 2026
How the vase generator builds its shapes, why it promises one closed contour per layer, and what drainage holes taught me about that promise.
- How the enclosure generator works23 August 2026
What happens between "Raspberry Pi 5" in the picker and a printable case with the ports in the right places, and the bug that printed solid screw holes for a week.