mesh_example.py

import cadquery as cq
import math

def mesh_pattern(
        radius=2, 
        height = 10, 
        m_radius=.5, 
        m_padding = .5
):
    m_cylinder = (
        cq.Workplane("XY")
        .cylinder(radius*2, m_radius)
        .rotate((0,1,0),(0,0,0),90)
    )
    
    mesh = (
        cq.Workplane("XY")
    )
        
    circumference = math.floor(2 * math.pi * radius)
    mesh_repeat = math.floor(math.floor(circumference/(m_radius*2+m_padding )))

    if mesh_repeat % 2 == 1:
        mesh_repeat -= 1
        log('it\'s odd')
        
    rotation = 360 / (mesh_repeat)    
    log(f'circumferece {circumference}, repeat {mesh_repeat}, rotation {rotation}')
    for i in range(mesh_repeat):
        mesh = (
            mesh
            .union(
                m_cylinder
                .rotate((0,0,1),(0,0,0), rotation*i)
            )
        )
    return mesh

def exhaust_mesh(
        radius=2, 
        height = 10, 
        m_radius=.5, 
        m_padding = 0,
        col_rotate = 0
):
    cylinder = cq.Workplane("XY").cylinder(height, radius)
    r_pattern = mesh_pattern(
        radius = radius, 
        height = height, 
        m_radius=m_radius,
        m_padding = m_padding
    )
    
    c_pattern = (
        cq.Workplane("XY")
    )
    
    c_repeat = math.floor(height / (m_radius*2+m_padding*2))
    #log(f'c_repeat {c_repeat}')
    for i in range(c_repeat):
        c_pattern = c_pattern.union(
            r_pattern
            .translate((0,0,i*(m_radius*2+m_padding*2)))
            .rotate((0,0,1),(0,0,0), col_rotate*i)
        )
    #return c_pattern
    return (
        cylinder
        .cut(
            c_pattern
            .translate((0,0,-1*(height/2)+m_radius+m_padding*2))
        )
    )

test = exhaust_mesh(
    radius = 2,
    height = 10,
    m_radius = 0.5, 
    m_padding=.25,
    col_rotate = 23
)

show_object(test)