Parametric radial fan duct (9733 fan default)

Blower fans often come with a duct fitting, and I'm very surprised no one's made a replica of them for printing.

The included .stl is around the right size for a 9733 blower fan to fit a 19mm CPAP tube, and I've included the .scad file for customization. (It's unfortunately not compatible with Thingiverse Customizer since it requires BOSL2, but I recommend the excellent OpenSCAD Playground to play around with it.) I recommend customizing it at least a little, since most manufacturers don't really seem to follow the same design standards for blower fan sizes and outlets.

If you don't want a barb, set either barbWidth or barbHeight to 0. (or use the stl file labeled "-nobarb" but that won't always be the right size.)

The design should work for most sizes, but if one dimension is significantly longer than the rest (for example, setting ductHeight to 500) things get a little weird and parts start to break.

I recommend having your slicer generate supports, since no matter what way you print it there will be overhang.

Updates

1.1.0

• Added the ability to cut out a section of the fitting to be compatible with some non-standard blowing fan outlets
• Cleaned up the code a bit

1.0.1

• Updated .scad file to be drop-in compatible with OpenSCAD Playground

1.0.0

• No change from 0.1.3, but the design is finalized.

0.1.3

• Added barb for a hose fitting; the default size will fit a 22mm CPAP tube with 19mm rubber connection. Instructions to remove the barb (if unwanted) are in the model description.

0.1.2

• Added slight chamfering to the duct to improve airflow (there is now a cone around the base of the duct)
• Simplified .scad file structure into one single difference()
• The .scad file no longer requires (fittingDepth < fittingWidth), so you can customize to your heart's content
• Changed the include statement in the .scad file for relative linking (you still have to make sure the directory name is correct under your library directory)

0.1.1

• Added tapered edge to bottom of fitting
• Changed default width and depth (actually measured with the calipers this time)

0.1.0

• Initial release