parametric-funnel

Two parametric funnels for 3D printing, made in OpenSCAD.

funnel.scad	funnel_with_fins.scad

funnel.scad

A hollow funnel: a straight throat, a cone and a rim, made by spinning one profile. Set the variables at the top of the file, or call the module:

use <funnel.scad>

funnel(funnel_height = 60, funnel_top_radius = 50, throat_height = 20,
       throat_radius = 15, wall_thickness = 0.8, top_edge_height = 5);

Argument	Meaning
funnel_height	Height of the cone, in mm.
funnel_top_radius	Inside radius at the top of the cone, in mm.
throat_height	Height of the straight throat below the cone, in mm.
throat_radius	Inside radius of the throat, in mm.
wall_thickness	Wall thickness, square to the wall, in mm.
top_edge_height	Height of the straight rim above the cone, in mm.
smoothness_segments	Segments around the circumference. Default 128.

funnel_profile() returns the cross-section as points, for checking or reuse.

funnel_with_fins.scad

A solid funnel to print in vase mode, with an air gap channel that lets air out of the container, and optional twisted “turbo” fins. The fins are 0.1 mm slits cut into the cone, meant to print as ribs in vase mode. The file’s header gives the print settings: vase mode, with a 0.7 mm extrusion width.

Adapted from vase mode parametric funnel v2 by DrJones, licensed CC-BY. Set the parameters at the top of the file:

Parameter	Meaning
outer_diameter	Diameter of the wide end, in mm.
cone_angle	Included angle of the cone, in degrees.
stem_diameter	Diameter of the stem where it meets the cone, in mm.
stem_length	Length of the stem, in mm.
stem_taper	How much narrower the stem’s end is, as a % of its diameter.
air_gap_percentage	Diameter of the air gap channel, as a % of the stem diameter. 0 for none.
fin_type	0 for no fins, 1 for the original fins, 2 for improved fins.
fin_count	Number of fins.
fin_twist_angle	How far the fins twist, in degrees.
fin_direction	0 for clockwise, 1 for counterclockwise.
fin_depth	How deep the fins reach into the cone, in mm.

Development

With just, OpenSCAD and Python 3, just test checks the plain funnel’s profile, then renders the plain funnel and the finned funnel with each fin type and checks that each is one solid of the expected size. just images renders the pictures in assets/.

Acknowledgement

Also used as a reference: Parametric funnel by Jaakko Kentta.

License

MIT. See LICENSE. funnel_with_fins.scad is adapted from DrJones’s CC-BY design, credited above.