plot_box.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

__author__ = 'Gary Williams, Grin Technologies'

import sys
import math

from reportlab.lib.pagesizes import letter
from reportlab.lib.units import inch, mm
from reportlab.lib.colors import black, white, blue, red

import PDF # https://pastebin.com/edit/imz8TQun

tab_size = 0.5 * inch
matl_thick = 6 * mm
margin = 0.25 * inch
gap = 0.125 * inch

box_height = 4.5 * inch + 2 * matl_thick
box_width = 6 * inch + 2 * matl_thick
box_length = 8 * inch + 2 * matl_thick

m3_hole_dia = 2.89 * mm
m3_nut_thickness = 2.29 * mm
m3_nut_width_flat_flat = 5.41 * mm
m3_nut_width_point_point = 6.10 * mm

screw_length = 10 * mm
screw_hole_dia = m3_hole_dia
nut_thickness = m3_nut_thickness
nut_width = m3_nut_width_flat_flat

cut_holes_for_screws = True
cut_slots_for_screws = True

def plot_edge(pdf, l):
    float_num_tabs = (l - 2 * matl_thick) / (2.0 * tab_size)

    num_tabs = int(float_num_tabs + 0.5)
    adj_tab_size = (l - 2 * matl_thick) / (2.0 * num_tabs)

    for i in range(0, num_tabs):
        if cut_holes_for_screws and i == 0:
            x, y, d = pdf.x, pdf.y, pdf.dir
            pdf.forward(0.5 * adj_tab_size, False)
            pdf.turn_left()
            pdf.forward(0.5 * matl_thick, False)
            pdf.circle(pdf.x, pdf.y, 0.5 * screw_hole_dia)
            pdf.set_xy(x, y)
            pdf.set_dir(d)

        pdf.turn_left()
        pdf.forward(0.5 * matl_thick)
        pdf.curve_right(0.5 * matl_thick)
        pdf.forward(adj_tab_size - matl_thick)
        pdf.curve_right(0.5 * matl_thick)
        pdf.forward(0.5 * matl_thick)
        pdf.turn_left()

        if cut_slots_for_screws and (i == num_tabs - 1):
            z0 = 0.5 * (adj_tab_size - screw_hole_dia)

            screw_depth = screw_length - matl_thick - nut_thickness + 1 * mm

            z1a = 2.0 / 3.0 * screw_depth
            z1b = screw_depth - z1a
            z2 = 0.5 * (nut_width - nut_thickness)

            pdf.forward(z0)
            pdf.turn_right()

            pdf.forward(z1a)
            pdf.turn_right()
            pdf.forward(z2)
            pdf.turn_left()
            pdf.forward(nut_thickness)
            pdf.turn_left()
            pdf.forward(z2)
            pdf.turn_right()
            pdf.forward(z1b)

            pdf.turn_left()
            pdf.forward(screw_hole_dia)
            pdf.turn_left()

            pdf.forward(z1b)
            pdf.turn_right()
            pdf.forward(z2)
            pdf.turn_left()
            pdf.forward(nut_thickness)
            pdf.turn_left()
            pdf.forward(z2)
            pdf.turn_right()
            pdf.forward(z1a)

            pdf.turn_right()
            pdf.forward(z0)

        else:
            pdf.forward(adj_tab_size)

def plot_box_side(pdf, x0, y0, w, h):
#   pdf.rect(x0, y0, w, h)
    pdf.set_xy(x0 + matl_thick, y0 + matl_thick)
    pdf.set_dir(PDF.Direction.Up.value)
    for i in range(2):
        plot_edge(pdf, h)
        pdf.turn_right()
        plot_edge(pdf, w)
        pdf.turn_right()

pdf = PDF.PDF(
    'box.pdf',
    PDF.PageOrientation.Landscape,
    (24 * inch, 14 * inch),
)

pdf.setLineWidth(0)
plot_box_side(pdf, margin, pdf.get_page_height() - margin - box_height, box_length, box_height)
plot_box_side(pdf, margin, pdf.get_page_height() - margin - box_height - gap - box_width, box_length, box_width)
plot_box_side(pdf, margin + box_length + gap, pdf.get_page_height() - margin - box_height, box_width, box_height)

pdf.save()