Add script to generate 3D models for SOT packages

generate_sot.py

@@ -0,0 +1,179 @@
+"""
+Generate only the 3D models for SOT packages
+"""
+from os import path
+
+from typing import Iterable, Tuple
+
+import cadquery as cq
+
+from cadquery_helpers import StepAssembly, StepColor
+
+
+def generate(
+    name: str,
+    body_width: float,
+    body_length: float,
+    total_height: float,
+    lead_span: float,
+    lead_height: float,
+    lead_contact_length: float,
+    leads_left: Iterable[Tuple[str, float, float]],
+    leads_right: Iterable[Tuple[str, float, float]],
+    pin1_indicator: bool,
+) -> None:
+    print(f'Generating pkg 3D model "{name}"')
+
+    assembly = StepAssembly(name)
+
+    body_standoff = 0.1
+    body_height = total_height - body_standoff
+    body_chamfer = 0.15
+    dot_diameter = min(body_width * 0.25, 0.8)
+    dot_position = dot_diameter
+    dot_depth = 0.1
+    lead_z_top = body_standoff + (body_height / 2)
+    bend_radius = min(0.1 + (lead_height / 2), lead_contact_length / 3)
+
+    dot_center = (
+        -(body_width / 2) + dot_position,
+        (body_length / 2) - dot_position,
+        body_standoff + body_height - dot_depth
+    )
+
+    body = cq.Workplane('XY', origin=(0, 0, body_standoff + (body_height / 2))) \
+        .box(body_width, body_length, body_height) \
+        .edges().chamfer(body_chamfer)
+    if pin1_indicator:
+        body = body.workplane(origin=(dot_center[0], dot_center[1]), offset=(body_height / 2) - dot_depth) \
+            .cylinder(5, dot_diameter / 2, centered=(True, True, False), combine='cut')
+    assembly.add_body(body, 'body', StepColor.IC_BODY)
+
+    if pin1_indicator:
+        dot = cq.Workplane('XY', origin=dot_center) \
+            .cylinder(0.05, dot_diameter / 2, centered=(True, True, False))
+        assembly.add_body(dot, 'dot', StepColor.IC_PIN1_DOT)
+
+    leads_by_width = dict()
+    for x_sgn, rotation, leads in [(-1, 0, leads_left), (1, 180, leads_right)]:
+        for lead_name, lead_y, lead_width in leads:
+            if lead_width not in leads_by_width:
+                lead_path = cq.Workplane("XZ") \
+                    .hLine(lead_contact_length - (lead_height / 2) - bend_radius) \
+                    .ellipseArc(x_radius=bend_radius, y_radius=bend_radius, angle1=270, angle2=360, sense=1) \
+                    .vLine(lead_z_top - lead_height - (2 * bend_radius)) \
+                    .ellipseArc(x_radius=bend_radius, y_radius=bend_radius, angle1=90, angle2=180, sense=-1) \
+                    .hLine((lead_span / 2) - bend_radius - lead_contact_length + (lead_height / 2))
+                leads_by_width[lead_width] = cq.Workplane('ZY') \
+                    .rect(lead_height, lead_width) \
+                    .sweep(lead_path)
+            assembly.add_body(
+                leads_by_width[lead_width],
+                'lead-{}'.format(lead_name),
+                StepColor.LEAD_SMT,
+                location=cq.Location((
+                    x_sgn * lead_span / 2,
+                    lead_y,
+                    lead_height / 2,
+                ), (0, 0, 1), rotation)
+            )
+
+    # Save without fusing for massively better minification!
+    out_path = path.join('out_3d', 'sot', f'{name}.step')
+    assembly.save(out_path, fused=False)
+
+
+if __name__ == '__main__':
+    generate(
+        name='SOT223-4P230_700X180L175X75T175X300',
+        body_width=3.5,
+        body_length=6.5,
+        total_height=1.8,
+        lead_span=7.0,
+        lead_height=0.27,
+        lead_contact_length=0.9,
+        leads_left=[
+            ('1', 2.3, 0.7),
+            ('2', 0, 0.7),
+            ('3', -2.3, 0.7),
+        ],
+        leads_right=[
+            ('4', 0, 3.0),
+        ],
+        pin1_indicator=True,
+    )
+    generate(
+        name='SOT23-3P95_230X110L50X40',
+        body_width=1.3,
+        body_length=2.9,
+        total_height=1.1,
+        lead_span=2.3,
+        lead_height=0.14,
+        lead_contact_length=0.4,  # JEDEC says 0.5mm, but it looks impossible
+        leads_left=[
+            ('1', 0.95, 0.4),
+            ('2', -0.95, 0.4),
+        ],
+        leads_right=[
+            ('3', 0, 0.4),
+        ],
+        pin1_indicator=False,
+    )
+    generate(
+        name='SOT23-5P95_280X145L60X40',
+        body_width=1.6,
+        body_length=2.9,
+        total_height=1.45,
+        lead_span=2.8,
+        lead_height=0.17,
+        lead_contact_length=0.45,
+        leads_left=[
+            ('1', 0.95, 0.4),
+            ('2', 0, 0.4),
+            ('3', -0.95, 0.4),
+        ],
+        leads_right=[
+            ('4', -0.95, 0.4),
+            ('5', 0.95, 0.4),
+        ],
+        pin1_indicator=True,
+    )
+    generate(
+        name='SOT23-6P95_280X145L60X40',
+        body_width=1.6,
+        body_length=2.9,
+        total_height=1.45,
+        lead_span=2.8,
+        lead_height=0.17,
+        lead_contact_length=0.45,
+        leads_left=[
+            ('1', 0.95, 0.4),
+            ('2', 0, 0.4),
+            ('3', -0.95, 0.4),
+        ],
+        leads_right=[
+            ('4', -0.95, 0.4),
+            ('5', 0, 0.4),
+            ('6', 0.95, 0.4),
+        ],
+        pin1_indicator=True,
+    )
+    generate(
+        name='SOT353-5P65_210X110L42X25',
+        body_width=1.25,
+        body_length=2.0,
+        total_height=1.10,
+        lead_span=2.1,
+        lead_height=0.17,
+        lead_contact_length=0.15 + 0.17,
+        leads_left=[
+            ('1', 0.65, 0.25),
+            ('2', 0, 0.25),
+            ('3', -0.65, 0.25),
+        ],
+        leads_right=[
+            ('4', -0.65, 0.25),
+            ('5', 0.65, 0.25),
+        ],
+        pin1_indicator=True,
+    )