Cadquery Manufacturability

CadQuery manufacturability — DFM pass

Purpose

Make the part manufacturable and sourceable: correct fastener diameters, counterbores, process constraints, vendor BOM text, identification engraving. Run after detailing so counterbores are not destroyed by later fillets.

What this pass is NOT

• No structural ribs/gussets (detailing)
• No cosmetic fillets unless process-required (e.g. cast fillet note in comment when radius already exists in detailing)
• No changing functional mate diameters without updating common.py and the partner part

Authoritative rules

cad-generation.txt — Mechanical Interfaces, Standard Vendor Parts.

Inputs

• Detailed part file from cadquery-part-detailing
• Mating list: joint kind per partner
• Process: machined | sheet_metal | print | cast
• Which side of each bolted joint this part is (clamped → clearance; receiver → tap pilot)

Fastener responsibility split (critical)

For each bolted mate, exactly one part gets clearance + counterbore; the partner gets tap pilot — positions from common.py:

# common.py
M3_MOUNT_PTS = [(30, 15), (-30, 15), (30, -15), (-30, -15)]

# parts/bracket.py (clamped) — DFM pass
from common import M3_MOUNT_PTS, M3_CLEAR_DIA, M3_CBORE_DIA, M3_CBORE_DEPTH, PLATE_T
clear = cq.Workplane("XY").pushPoints(M3_MOUNT_PTS).circle(M3_CLEAR_DIA / 2).extrude(PLATE_T + 1)
cbore = cq.Workplane("XY").pushPoints(M3_MOUNT_PTS).circle(M3_CBORE_DIA / 2).extrude(-M3_CBORE_DEPTH)
bracket = bracket.cut(clear).cut(cbore)

# parts/base.py (receiver) — DFM pass
from common import M3_MOUNT_PTS, M3_TAP_DIA, TAP_DEPTH
pilot = cq.Workplane("XY").pushPoints(M3_MOUNT_PTS).circle(M3_TAP_DIA / 2).extrude(-TAP_DEPTH)
base = base.cut(pilot)

Never put both clearance and tap on the same part unless it is a standalone test piece.

Fastener table (mm)

Define M3_CLEAR_DIA, M3_TAP_DIA, etc. in common.py when first used.

DFM checklist

Apply every item that fits:

All processes

• Mounting holes on anything that bolts to another surface — even if mate part is out of scope
• Vendor procurement comment (4 lines: category, key dims, standard, sample SKU) above interface geometry
• Part identification on a non-cosmetic face: .faces("<Z").workplane().text("P/N …", 4, -0.3, combine="cut")

Press-fit / welded / snap

• Press-fit: document interference in comment; model zero gap
• Welded: flush faces + # WELD — fillet weld along ... comment
• Snap-fit: explicit undercut dimension in comment + modeled beam/ledge

Machined

• Min wall 1.5 mm (Al), 1.0 mm (steel)
• No sharp internal pocket corners without noting min cutter radius (detailing should have fillet)

Sheet metal

• Uniform thickness; bend radius ≥ t; hole-to-edge ≥ 2t

3D print

• Min wall ≥ 1.2 mm; no modeled threads — clearance + comment for insert

Cast / molded

• 1–3° draft on vertical walls (model or comment)
• Uniform wall ±25%

Build order

1. Re-open parts/<name>.py inside build_*() after detailing block.
2. Add # ---- DFM ---- section.
3. Each cut/union: single-extrusion tool, one at a time.
4. Vendor comments immediately above related geometry.
5. Return part; keep result = build_<name>().

Workflow

1. Edit part file.
2. Smoke exec + orchestrator cadquery-render.
3. Orchestrator cadquery-interference-check — counterbores often clash with neighbors.

Output

Updated parts/<function_name>.py. Do not modify assembly.py — orchestrator swaps the built part.