A shop vac hose that will not reach a tool port, a dryer duct one size off, a funnel that belongs on a different bottle. Measure both ports, say whether each end goes inside or over, and this builds the part that joins them.
The two ends are described from the port's side, not the part's.
Calipers beat a tape measure here. A millimetre is the difference between a part that seals and one that falls off. Nominal hose sizes lie: a two and a half inch hose is rarely 63.5 mm.
| Material | PETG, or PLA |
| Layer height | 0.2 mm |
| Walls | 3 or more |
| Infill | Anything, it is all wall |
| Supports | None |
| Orientation | As downloaded |
It stands on end A, so nothing overhangs past 45 degrees and the seam runs straight up the side. For a joint that has to hold vacuum, more walls beat more infill.
Printers disagree about holes by a few tenths. Change how tight by one step and print again. The first one is a test print: at these sizes it costs pennies.
To stop guessing altogether, print the Tolerance Kit once. It measures what this printer does to a hole, and its numbers then appear at the top of the how tight list here, on this part and on the others.
For a joint that has to hold, print it tight and warm it with a hair dryer before pushing it home, or wrap the spigot in a turn of tape.
The geometry is a small Javascript module. It runs in node as happily as here if you would rather script it.