"""Aluminium T-slot extrusion, metric series. Simplified profile: square section with a rectangular slot on each
side and a centre bore. Slot shapes differ between makers: check your supplier's drawing for exact fits.
The profile is centred on the origin in XY and extruded along +Z."""
from steve import Model

series = "2020"  # Profile series
length = 100  # mm Length

# series: (side a, slot opening w, slot depth t, centre bore b)
SERIES = {
    '2020': (20.0, 6.2, 6.0, 4.2),
    '3030': (30.0, 8.2, 9.0, 6.8),
    '4040': (40.0, 8.2, 12.0, 6.8),
}
a, w, t, b = SERIES[series]
h = a / 2

model = Model()
with model.sketch("profile", on="XY", name="Section") as sk:
    sk.polyline("outline", [
        (-h, -h), (-w / 2, -h), (-w / 2, -h + t), (w / 2, -h + t), (w / 2, -h),
        (h, -h), (h, -w / 2), (h - t, -w / 2), (h - t, w / 2), (h, w / 2),
        (h, h), (w / 2, h), (w / 2, h - t), (-w / 2, h - t), (-w / 2, h),
        (-h, h), (-h, w / 2), (-h + t, w / 2), (-h + t, -w / 2), (-h, -w / 2),
    ])
    sk.circle("bore", (0, 0), b / 2)
model.extrude("bar", "profile", distance=length)
result = model.result()