Creates a cube or rectangular prism (i.e., a "box") in the first octant. When center is true, the cube is centered on the origin. Argument names are optional if given in the order shown here.

cube(size = [x,y,z], center = true/false);
cube(size =  x ,     center = true/false);

parameters:

size

single value, cube with all sides this length

3 value array [x,y,z], rectangular prism with dimensions x, y and z.

center

false (default), 1st (positive) octant, one corner at (0,0,0)

true, cube is centered at (0,0,0)

default values:  cube();   yields:  cube(size = [1, 1, 1], center = false);

examples:

equivalent scripts for this example
 cube(size = 18);
 cube(18);
 cube([18,18,18]);
 .
 cube(18,false);
 cube([18,18,18],false);
 cube([18,18,18],center=false);
 cube(size = [18,18,18], center = false);
 cube(center = false,size = [18,18,18] );

equivalent scripts for this example
 cube([18,28,8],true);
 box=[18,28,8];cube(box,true);

Creates a sphere at the origin of the coordinate system. The r argument name is optional. To use d instead of r, d must be named.

Parameters

r

Radius. This is the radius of the sphere. The resolution of the sphere is based on the size of the sphere and the $fa, $fs and $fn variables. For more information on these special variables look at: OpenSCAD_User_Manual/Other_Language_Features

d

Diameter. This is the diameter of the sphere.

$fa

Fragment angle in degrees

$fs

Fragment size in mm

$fn

Resolution

 default values:  sphere();   yields:   sphere($fn = 0, $fa = 12, $fs = 2, r = 1);

Usage Examples

sphere(r = 1);
sphere(r = 5);
sphere(r = 10);
sphere(d = 2);
sphere(d = 10);
sphere(d = 20);

// this creates a high resolution sphere with a 2mm radius
sphere(2, $fn=100); 

// also creates a 2mm high resolution sphere but this one 
// does not have as many small triangles on the poles of the sphere
sphere(2, $fa=5, $fs=0.1); 

Creates a cylinder or cone centered about the z axis.

Called with no arguments, and $fn at its default, the module creates a 1 unit tall, pentagonal solid on the X-Y plane that is inscribed in a unit circle.

Parameter names are optional if the first three are given in the order of height, radius 1 (bottom radius), and radius 2 (top radius) as seen here:

cylinder(h, r1, r2);

Omitting r1 or r2 leaves them at their default values of one resulting in a truncated cone (a Conical Frustum). The named parameters may be given in any order, but for any of the diameter related ones only the first given is used. Giving a diameter/radius value of zero results in a cone shape, and setting both to zero make no shape at all.

Parameters

h : (pos 1) height of the cylinder, must be greater than zero

r1 : (pos 2) radius of bottom circular face.

r2 : (pos 3) radius of top circular face.

center : (pos 4)

false (default), height is from the X-Y plane to positive Z

true height is centered vertically on the X-Y plane

r  : radius of both end faces

d  : diameter of both end faces. [Note: Requires version 2014.03 (see [Release Notes ] )]

d1 : diameter of bottom circular face. [Note: Requires version 2014.03 (see [Release Notes ] )]

d2 : diameter of top circular face. [Note: Requires version 2014.03 (see [Release Notes ] )]

$fa : minimum angle (in degrees) of each fragment.

$fs : minimum circumferential length of each fragment.

$fn : fixed number of fragments in 360 degrees. Values of 3 or more override $fa and $fs

$fa, $fs and $fn must be named parameters. click here for more details,.

default values:
 cylinder($fn = 0, $fa = 12, $fs = 2, h = 1, r1 = 1, r2 = 1, center = false);
 cylinder($fn = 0, $fa = 12, $fs = 2, h = 1, d1 = 1, d2 = 1, center = false); // radius = 0.5

All of the following calls result in this conic frustum:

cylinder(h=15, r1=9.5, r2=19.5, center=false);
cylinder(  15,    9.5,    19.5, false);
cylinder(  15,    9.5,    19.5);
cylinder(  15,    9.5, d2=39  );
cylinder(  15, d1=19,  d2=39  );
cylinder(  15, d1=19,  r2=19.5);

All of these result in this cone:

cylinder(h=15, r1=10, r2=0, center=true);
cylinder(  15,    10,    0,        true);
cylinder(h=15, d1=20, d2=0, center=true);

• center = false
• center = true

equivalent scripts
 cylinder(h=20, r=10, center=true);
 cylinder(  20,   10, 10,true);
 cylinder(  20, d=20, center=true);
 cylinder(  20,r1=10, d2=20, center=true);
 cylinder(  20,r1=10, d2=2*10, center=true);

use of $fn

Larger values of $fn create smoother surfaces at the cost of greater rendering time. A good practice is to set it in the range of 10 to 20 during development of a shape, then change to a value larger than 30 for rendering image or exporting shape files.

However, use of small values can produce some interesting non circular objects. A few examples are show here:

scripts for these examples
 cylinder(20,20,20,$fn=3);
 cylinder(20,20,00,$fn=4);
 cylinder(20,20,10,$fn=4);

undersized holes

Using cylinder() with difference() to place holes in objects creates undersized holes. This is because circular paths are approximated with polygons inscribed within in a circle. The points of the polygon are on the circle, but straight lines between are inside. To have all of the hole larger than the true circle, the polygon must lie wholly outside of the circle (circumscribed). Modules for circumscribed holes

script for this example
 poly_n = 6;
 color("blue") translate([0, 0, 0.02]) linear_extrude(0.1) circle(10, $fn=poly_n);
 color("green") translate([0, 0, 0.01]) linear_extrude(0.1) circle(10, $fn=360);
 color("purple") linear_extrude(0.1) circle(10/cos(180/poly_n), $fn=poly_n);

In general, a polygon of radius ${\displaystyle r}$ has a radius to the midpoint of any side as ${\displaystyle r_{m}=r\cos(180/n)}$. If only the midpoint radius ${\displaystyle r_{m}}$ is known (for example, to fit a hex key into a hexagonal hole), then the polygon radius is ${\displaystyle r={\frac {r_{m}}{\cos(180/n)}}}$.