Needed one for the gazebo/grill area so whipped it out quick, came out more elegant than expected. Includes pattern to cut out a "floor" for the ash pit from a sheet of metal, to protect the plastic from burning. Notches measured to fit regular cigarettes in such a way you can push the cigarette in, to keep it gripped so it won't be taken away by wind.

Instead of the metal insert you can use high-temperature spray paint; not tested but allegedly works OK on 3D-printed ashtrays.

parametric FreeCAD project included,if you want a different size and depth; this one is fairly large.

Tested for three evenings by now, works as intended.

Regarding the intended outdoor use - I fully expect the PLA to degrade in outdoor use within a couple years, at which point I'll just print another, and hopefully reuse the metal insert.

Longer

Longer LK5 Pro

No

8%

If you have inflexible print bed surface, e.g. glass, you may want to use glue stick or similar, otherwise the large bottom may stick very hard.

Settings: thick walls, 3+ layers, and even thicker top 5+ layers for decent thermal capacity. Bottom and infill can be kept quite flimsy and thin (2 layers, 8% infill)

Print the PDF, cut out the shape from paper, paste to sheet metal (doesn't have to be thick; the sort used in food/coffee cans is quite sufficient; drink cans are a little thin; I used case of an old CD-ROM drive), then cut the shape, then glue it to the bottom of the ash-pit, using a glue that has some bulk, like rubber-cement, epoxy, silicone - not cyanoacrylic/super-glue. The walls and notches still aren't protected from melting but the worst of it is averted.