When using this module, you should use points to represent the 2D shape. If your 2D shape is not solid, indexes of triangles are required. Seesweep for details.

Its$fa,$fs and$fn parameters are consistent with thecylinder module.

Parameters

• shape_pts : A list of points represent a shape. See the example below.
• radius : The radius of the cylinder. The radius of the cylinder. It also accepts a vector[r1, r2].r1 is the bottom radius andr2 is the top radius of a cone.
• levels : The level count is performed every 360 degrees.
• level_dist : The distance between two vertial points.
• vt_dir :"SPI_DOWN" for spiraling down."SPI_UP" for spiraling up. The default value is"SPI_DOWN".
• rt_dir :"CT_CLK" for counterclockwise."CLK" for clockwise. The default value is"CT_CLK".
• twist : The number of degrees of through which the shape is extruded.
• scale : Scales the 2D shape by this value over the length of the extrusion. Scale can be a scalar or a vector.
• triangles :"SOLID" (default),"HOLLOW" or user-defined indexes. Seesweep for details.
• $fa,$fs,$fn : Checkthe cylinder module for more details.

Examples

use <helix_extrude.scad>shape_pts = [    [5, -2],    [5, 2],     [4, 2],    [4, 0],    [-4, 0],    [-4, 2],        [-5, 2],        [-5, -2]];helix_extrude(shape_pts,     radius = 40,     levels = 5,     level_dist = 10,    vt_dir = "SPI_UP");

use <helix_extrude.scad>r1 = 40;r2 = 20;levels = 5;level_dist = 10;shape_pts = [    [10, -2],    [10, 2],    [9, 2],    [9, 0],    [1, 0],    [1, 2],    [0, 2],    [0, -2],];helix_extrude(shape_pts,     radius = [r1, r2],     levels = levels,     level_dist = level_dist,    vt_dir = "SPI_UP");%cylinder(h = levels * level_dist, r1 = r1, r2 = r2);