"""Split lock washer (spring washer), DIN 127 form B (square ends), M2 to M100.

One helical turn of a rectangular section: inner diameter d1 (min), outer diameter d2 (max), thickness s and free
height h (form B, max). The section stays in the plane through the axis as it climbs, so the washer is exactly
h high and d2 wide; the split is where the two ends meet, h - s apart. It lies on the XY plane at the origin,
climbing along +Z.
"""
import cadquery as cq
from steve import Model

size = "M3"  # Thread size
material = "spring-steel"  # Material

# DIN 127:1987-10 table (https://fasten.it/norms/norm/din_127). size: (d1 min, d2 max, s nominal, h max form B)
DIMENSIONS = {
    "M2": (2.1, 4.4, 0.5, 1.2), "M2.2": (2.3, 4.8, 0.6, 1.4), "M2.5": (2.6, 5.1, 0.6, 1.4),
    "M3": (3.1, 6.2, 0.8, 1.9), "M3.5": (3.6, 6.7, 0.8, 1.9), "M4": (4.1, 7.6, 0.9, 2.1), "M5": (5.1, 9.2, 1.2, 2.8),
    "M6": (6.1, 11.8, 1.6, 3.8), "M7": (7.1, 12.8, 1.6, 3.8), "M8": (8.1, 14.8, 2.0, 4.7), "M10": (10.2, 18.1, 2.2, 5.2),
    "M12": (12.2, 21.1, 2.5, 5.9), "M14": (14.2, 24.1, 3.0, 7.1), "M16": (16.2, 27.4, 3.5, 8.3),
    "M18": (18.2, 29.4, 3.5, 8.3), "M20": (20.2, 33.6, 4.0, 9.4), "M22": (22.5, 35.9, 4.0, 9.4),
    "M24": (24.5, 40.0, 5.0, 11.8), "M27": (27.5, 43.0, 5.0, 11.8), "M30": (30.5, 48.2, 6.0, 14.2),
    "M36": (36.5, 58.2, 6.0, 14.2), "M39": (39.5, 61.2, 6.0, 14.2), "M42": (42.5, 68.2, 7.0, 16.5),
    "M45": (45.5, 71.2, 7.0, 16.5), "M48": (49.0, 75.0, 7.0, 16.5), "M52": (53.0, 83.0, 8.0, 18.9),
    "M56": (57.0, 87.0, 8.0, 18.9), "M60": (61.0, 91.0, 8.0, 18.9), "M64": (65.0, 95.0, 8.0, 18.9),
    "M68": (69.0, 99.0, 8.0, 18.9), "M72": (73.0, 103.0, 8.0, 18.9), "M80": (81.0, 111.0, 8.0, 18.9),
    "M90": (91.0, 121.0, 8.0, 18.9), "M100": (101.0, 131.0, 8.0, 18.9),
}
# material choice: (STEVE material library id, appearance colour)
MATERIALS = {
    "spring-steel": ("steel-c60e", "#2f3134"),   # spring steel, black / phosphated
    "stainless-a2": ("stainless-304", "#c9ccd0"),
    "stainless-a4": ("stainless-316", "#c9ccd0"),
}

d1, d2, s, h = DIMENSIONS[size]
material_id, colour = MATERIALS[material]
r1 = d1 / 2
r2 = d2 / 2
rise = h - s

path = cq.Wire.makeHelix(rise, rise, (r1 + r2) / 2)
section = cq.Workplane("XZ").center((r1 + r2) / 2, s / 2).rect(r2 - r1, s)
coil = section.sweep(cq.Workplane().add(path), isFrenet=True)   # on a helix the Frenet frame keeps the section in its axial plane

model = Model()
model.add("washer", coil, name="Washer")
model.material(material_id, color=colour)
result = model.result()