Vent Duct Quick Connect System

These vase-mode prints can be used to set up flexible ducting (6 inch, 4 inch, 3 inch) with tube_end connectors to allow for quick reconfigurations.  This only works for exhaust vent ducting (suction, not pressure), and only if the duct connections aren't put under any tension.  The parts aren't particularly sturdy; they're optimized for quick printing not for strength.

The OD of the nominal 6 inch, 4 inch, and 3 inch portions is set to exactly the nominal size.  The ID of the larger end pieces is what has the stated clearance (0p00, 0p17, 0p25).  I recommend test-printing a few layers of the larger end (of any part that has a larger end) to verify reasonable fit and adjusting the clearance in the .f3d as needed before printing a whole part.

On an mk3s+, with 0.98 extrusion multiplier and 1.2 mm extrusion width on a 0.4 mm nozzle, the 0p00 clearance parts just barely connect together with themselves, with the particular PETG I was using.

The 0p25 clearance seems to work fairly well for connecting to 3D printed duct adapters that aren't printed in vase mode.  The 0p17 clearance also can work for those but is quite a bit tighter.

PETG seems to have enough flexibility and strength to tolerate being clamped onto flex ducting without breaking, but don't crank it down too hard or it probably will break.  I wouldn't recommend PLA for these, but in some usages it could work for a while.

As a usage example, you could quickly route a flexible duct to some temporary location in a garage or room where you might be doing a one-off project involving stinky resin or soldering or stinky paint or glue or a temporary source of excess heat or whatever, then quickly reconfigure things back to normal once that's done sucking fumes/heat outside.

See also this print for splitting a 6 inch duct into three 4 inch ducts:

https://www.prusaprinters.org/prints/110253-1_6_to_3_4-duct-adapter

There are also models around for splitting 1 to 2, and 1 to 4.  As long as those have OD == nominal, those should also work with these quick-connects.

These aren't really meant for interfacing with sheet metal ducting / adaptors / T splitters / etc, but with enough clearance maybe they'd sorta work, probably with quite a bit of leakage.

The .f3d is parameterized.  In particular if you have a larger diameter nozzle like 0.6 or 0.8 or more, you could boost the extrusion width in the .f3d and in the slicer to get overall stronger parts.  The pre-prepared parts all assume 0.4 mm nozzle capable of doing a vase mode 1.2mm extrusion width (which normally would be pushing extrusion width pretty far, but works fine for vase mode).