manufacturing-knowledge

name	manufacturing-knowledge
description	Technical specifications, material properties, and cost models for CNC Milling and Injection Molding. Use this when the task specifies a 'max_unit_cost' or 'target_quantity', or when planning for specific manufacturing processes.

Manufacturing & Economic Knowledge

This skill provides the procedural and domain knowledge required to design parts that meet specific manufacturing constraints and economic targets.

1. Dynamic Data Access

To get the current material properties, density, and cost constants, use the runtime surfaces that are actually exposed in the workspace. Do not rely on your internal knowledge or hardcoded values in this file.

Use:

• read_file("config/manufacturing_config.yaml") for material properties, process costs, and catalog data.
• Planner roles: validate_costing_and_price() to validate, price, and deterministically normalize the cost and weight totals in assembly_definition.yaml.

Do not browse scripts/ or invent helper tools that are not exposed to your role.

2. CNC Milling (3-Axis)

Best for: Low volumes (1-100 units), high strength, aluminum parts. Detailed Reference: references/cnc.md

Cost Formula

$$Total = Setup + (Material + Run) \times Quantity$$

• Setup Cost: Fixed cost (~$80.00). 50% discount on reuse.
• Material Cost: Based on Stock Bounding Box volume.
• Run Cost: Machining time based on Removed Volume ($Stock - Part$).

Design Constraints

• Undercuts: Forbidden. All faces must be accessible from +Z.
• Internal Corners: Minimum tool radius is 3.0mm. Use fillet(radius=3.1).

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3. Injection Molding (IM)

Best for: High volumes (>1,000 units), plastic parts, low unit cost. Detailed Reference: references/injection_molding.md

Cost Formula

$$Total = Tooling + (Material + Cycle) \times Quantity$$

• Tooling Cost: High fixed cost. Amortized over volume. 90% discount on mold reuse.
• Material Cost: Based on actual part volume.
• Cycle Cost: Driven by Cooling Time ($CoolingTime \propto Thickness^2$).

Design Constraints

• Draft Angles: Mandatory for vertical faces. Minimum 2.0 degrees.
• Wall Thickness: Keep between 1.0mm and 4.0mm. Thick walls exponentially increase cycle cost.
• Undercuts: Faces must be reachable from either +Z or -Z (2-part mold).

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4. Economic Strategy

• Quantity < 100: Prefer CNC or 3D Printing.
• Quantity > 1000: Always prefer Injection Molding if geometry allows.
• Method comparison: Compare candidate methods at the requested quantity, not as single-unit quotes. Use setup/tooling cost separately from per-unit variable cost so the chosen process reflects the real production volume.
• Volume Optimization: Reducing part volume directly reduces material cost and run/cycle time.
• Part Reuse: Using multiple instances of the same part ID is significantly cheaper than multiple unique parts due to shared setup/tooling costs (50% discount for CNC setup, 90% discount for IM tooling).
• Weight Exactness: Treat the post-validation weight total as an exact deterministic output from the priced assembly breakdown, not a prose estimate.

5. Technical Design Patterns

Pattern: CNC Fillet Strategy

# Expert Pattern: Automatic filleting of internal vertical edges
internal_edges = part.edges().filter_by(Axis.Z).internal()
part = fillet(internal_edges, radius=3.1) # 3.1mm for 3.0mm tool clearance

Pattern: Injection Molding Shelling

# Expert Pattern: Creating a shelled plastic part
part = shell(part, openings=part.faces().sort_by(Axis.Z).last(), amount=-2.0)

Pattern: Draft for Release

# Expert Pattern: Applying 2-degree draft
part = draft(part, faces=part.faces().filter_by(Axis.Z), angle=2.0, pull_direction=(0,0,1))