lockerKeys/snap_on_templates.py

#!/usr/bin/env python3

import cadquery as cq
from cadquery import exporters

import key_bittings
from key_bittings import BittingSpecification

MM_PER_IN = 25.4

extra_key_thickness = 0.2

text_size = 4
text_depth = 0.5
text_margin = 2

lishi_width = 18 - 0.3
lishi_depth = 5
lishi_height = 9.98
lishi_overhang_height = 2.25
lishi_overhang_width = 1
lishi_overhang_radius = 1 - .000000001  # workaround to fillet a part with the same thickness
corner_radius = 0.5
side_thickness = 1
bottom_thickness = 2
back_thickness = 1.5
# this number is somewhat estimated, but quite important
# it is the offset from the end of the pliers to the point of the cutter
lishi_cutter_offset = .54 * MM_PER_IN
key_guide_height = 12.5

notch_width = 1
notch_height = 1.5
notch_depth = 0.5


def lishi_template(spec: BittingSpecification, name: str, depth: float, profile: cq.Sketch):
    key_guide_width = lishi_width/2 + side_thickness + spec.TFC - spec.BCC/2

    result = (
        cq
        .Workplane("front")
        .box(lishi_width + side_thickness * 2, lishi_depth + lishi_overhang_width, lishi_height + bottom_thickness)
        .tag("lishi_interface")
        .edges("not >Y").fillet(corner_radius)
    )

    # TODO: positioning could be better
    result = (
        result
        .faces("<Y").workplane().move(0, bottom_thickness/2)
        .rect(lishi_width, lishi_height).cutBlind(-lishi_depth)
    )

    result = (
        result
        .faces("<X", tag="lishi_interface").vertices(">Y and >Z")
        .workplane(offset=-side_thickness, centerOption="CenterOfMass")
        .rect(lishi_overhang_width, lishi_overhang_height, centered=False).extrude(-lishi_width)
        .edges(">Z").edges("<Y").fillet(lishi_overhang_radius)
    )

    result = (
        result
        .faces(">Y", tag="lishi_interface").vertices("<X and <Z")
        .workplane(centerOption="CenterOfMass").center(-key_guide_width, 0)
        .rect(key_guide_width, key_guide_height, centered=False).extrude(spec.key_thickness + extra_key_thickness + back_thickness, combine=False)
        .tag("key_guide")
        .edges("not <Y").fillet(corner_radius)
        .faces(">X", tag="key_guide").vertices("<Z and <Y").workplane(centerOption="CenterOfMass").center(0, bottom_thickness + lishi_cutter_offset - depth)
        .placeSketch(profile).cutThruAll()
        .union(result)  # this seems like a fairly bad way to do this, but it does work
    )

    result = (
        result
        .add(result.objects[0].Edges())
        .faces(">Y", tag="key_guide").vertices("<X and >Z").workplane(centerOption="CenterOfMass")
        # TODO: better positioning
        .moveTo(-(lishi_width / 2 + side_thickness), -notch_height/2)
        .rect(notch_width, notch_height).cutBlind(-notch_depth)
        .faces(">Y").workplane(centerOption="CenterOfMass").text(name, text_size, -text_depth)
    )

    return result


spec = key_bittings.national_disc_tumbler
for name, depth in spec.depths.items():
    profile = (
        cq.Sketch()
        .push([((spec.key_thickness + extra_key_thickness)/2, depth/2)])
        .rect(spec.key_thickness + extra_key_thickness, depth)

        # notch to hold key straight
        .push([(spec.key_thickness + extra_key_thickness - 0.5, 0.5 + 0.5)])
        .rect(1, 1, mode="s")

        # fillet inner corners
        .reset().vertices("not(>X or <X)") .fillet(0.3)
    )

    result = lishi_template(spec, name, depth, profile)
    exporters.export(result, f'national_disc_tumbler_{name}.stl')