"""Deep groove ball bearing, shielded (2Z), ISO 15 boundary dimensions.
Envelope: inner and outer rings and two recessed shields (four bodies; the balls behind the shields aren't modelled).
Centred on the origin with its axis along Z.

Material: rings in through-hardened high-carbon bearing steel (C60 from the material library, the closest it has to 100Cr6 / AISI 52100), ground; shields in cold-rolled steel (DC01)."""
from steve import Model

designation = "608"  # Bearing designation

# designation: (bore d, outside diameter D, width B)
BEARINGS = {
    '623': (3, 10, 4),
    '624': (4, 13, 5),
    '625': (5, 16, 5),
    '626': (6, 19, 6),
    '608': (8, 22, 7),
    '688': (8, 16, 5),
    '6000': (10, 26, 8),
    '6001': (12, 28, 8),
    '6002': (15, 32, 9),
    '6003': (17, 35, 10),
    '6004': (20, 42, 12),
    '6200': (10, 30, 9),
    '6201': (12, 32, 10),
    '6202': (15, 35, 11),
    '6203': (17, 40, 12),
    '6204': (20, 47, 14),
}
d, D, B = BEARINGS[designation]
ring = (D - d) * 0.22   # radial thickness of each ring's face
recess = min(0.4, B * 0.06)          # shield face below the ring faces
shield = max(0.2, min(0.6, B * 0.05))  # shield sheet thickness
gap = min(0.15, ring * 0.1)            # running clearance between a shield and the inner ring

model = Model()
with model.sketch("outer_sketch", on="XY", name="Outer ring") as sk:
    sk.circle("outside", (0, 0), D / 2)
    sk.circle("inside", (0, 0), D / 2 - ring)
model.extrude("outer_ring", "outer_sketch", distance=B, both=True, op="new", body="outer_ring")  # B in all, centred
with model.sketch("inner_sketch", on="XY", name="Inner ring") as sk:
    sk.circle("outside", (0, 0), d / 2 + ring)
    sk.circle("bore", (0, 0), d / 2)
model.extrude("inner_ring", "inner_sketch", distance=B, both=True, op="new", body="inner_ring")
model.plane("shield_top_plane", on="XY", offset=B / 2 - recess, name="Top shield face")
with model.sketch("shield_top_sketch", on="shield_top_plane", name="Top shield") as sk:
    sk.circle("out", (0, 0), D / 2 - ring)
    sk.circle("inn", (0, 0), d / 2 + ring + gap)
model.extrude("shield_top", "shield_top_sketch", distance=-shield, op="new", body="shield_top")
model.plane("shield_bottom_plane", on="XY", offset=-B / 2 + recess, name="Bottom shield face")
with model.sketch("shield_bottom_sketch", on="shield_bottom_plane", name="Bottom shield") as sk:
    sk.circle("out", (0, 0), D / 2 - ring)
    sk.circle("inn", (0, 0), d / 2 + ring + gap)
model.extrude("shield_bottom", "shield_bottom_sketch", distance=shield, op="new", body="shield_bottom")
model.material("steel-1c60", finish="polished")  # rings: hardened bearing steel
model.material("steel-dc01", bodies=["shield_top", "shield_bottom"], finish="machined")  # pressed steel shields
result = model.result()