Generate list of fasteners from FreeCAD files

generate-bom.py

"""
Run with FreeCAD's bundled interpreter.

Example:
    "C:/Program Files/FreeCAD 0.19/bin/python.exe" generate-bom.py
"""

from pathlib import Path
import re
import FreeCAD
import json
import FreeCADGui as Gui

Gui.setupWithoutGUI()

# This is cross-platform now as long as the script is in the project directory
target_file = Path(__file__).parent.joinpath('CAD/v1-180-assembly.FCStd')
# Regex pattern to match all fasteners
fastener_pattern = re.compile('.*-(Screw|Washer|HeatSet|Nut)')
bom = {'fasteners': {}, 'other': {}}
fasteners_bom = bom['fasteners']
other_bom = bom['other']
type_dictionary = {}  # for debugging purposes


def add_fastener_to_bom(part):
    fastener = part.Label
    # Prepare fastener string to be added to BOM
    # ISO type with descriptive name
    if hasattr(part, 'type'):
        if part.type == "ISO4762":
            fastener = f"Socket head {fastener}"
        if part.type == "ISO7380-1":
            fastener = f"Button head {fastener}"
        if part.type == "ISO4026":
            fastener = f"Grub {fastener}"
        if part.type == "ISO4032":
            fastener = f"Hex {fastener}"
        if part.type == "ISO7092":
            fastener = f"Small size {fastener}"
        if part.type == "ISO7093-1":
            fastener = f"Big size {fastener}"
        if part.type == "ISO7089":
            fastener = f"Standard size {fastener}"
        if part.type == "ISO7090":
            fastener = f"Standard size {fastener}"
    # Remove numbers at end if they exist (e.g. 'M3-Washer004' becomes 'M3-Washer')
    while fastener[-1].isnumeric():
        fastener = fastener[:-1]
    # Increment fastener qty if it already exists, otherwise set fastener qty to 1
    if fastener in fasteners_bom.keys():
        fasteners_bom[fastener] += 1
    else:
        fasteners_bom[fastener] = 1


def add_other_part_to_bom(part):
    part_name = part.Label

    while part_name[-1].isnumeric() or part_name[-1] == '-':
        part_name = part_name[:-1]
    if part_name in other_bom.keys():
        other_bom[part_name] += 1
    else:
        other_bom[part_name] = 1


def get_bom_from_freecad_document(assembly: FreeCAD.Document):
    parts = []
    # Get parts from this document
    parts += [x for x in assembly.Objects if x.TypeId.startswith('Part::')]
    for part in parts:
        # [debugging] Add type to dictionary so we can see which parts we want to add or filter out
        type_dictionary[part.Label] = part.TypeId
        # If fastener matches, add it to BOM
        if fastener_pattern.match(part.Label):
            add_fastener_to_bom(part)
        else:
            add_other_part_to_bom(part)
    # Recurse through each linked file
    for linked_file in assembly.findObjects("App::Link"):
        print("# Getting fasteners from", linked_file.Name)
        get_bom_from_freecad_document(linked_file.LinkedObject.Document)


print(f"# Getting fasteners from {target_file}")
# Get assembly object from filepath
cad_assembly = FreeCAD.open(str(target_file))
get_bom_from_freecad_document(cad_assembly)

# Pretty print BOM dictionary
print(json.dumps(bom, indent=4))

with open('bom-fasteners.json', 'w') as file:
    file.write(json.dumps(fasteners_bom, indent=4))

Changes:

• Iterate over all all linked documents
• Only need to reference assembly file now
• Separated fastener logic into add_fastener_to_bom function
• Add other parts (non-fasteners) to other_bom
• add_other_part_to_bom function simply filters numbers out at the end

TODO:

• Filter printed objects into a printed_bom dictionary
• Add static bom for parts not in CAD file (e.g. linear rail fasteners)
• Add dynamic parts (e.g. add T nuts for each bolt in the frame assembly