Here’s a consolidated set of core design considerations you’ll want to address up-front when architecting any Special Purpose Machine (SPM):
1. Functional Requirements
- Process Scope: Define every operation the SPM must perform (e.g., cut, weld, fill, inspect).
- Cycle Time & Throughput: Target units per hour and acceptable variation.
- Part Geometry & Tolerances: CAD models, GD&T callouts, allowable deviation.
- Material Characteristics: Weight, hardness, surface finish, temperature sensitivity.
2. Machine Layout & Footprint
- Floor Space & Clearances: Overall envelope, service aisles, operator zones.
- Workflow Flow-Chart: Sequence of stations, part-flow paths, buffer zones.
- Access & Egress: Maintenance access, emergency exits, material loading/unloading areas.
3. Mechanical & Structural Design
- Frame & Supports: Stiffness, vibration damping, material selection (e.g., welded steel, aluminum).
- Actuation: Choice of servos vs. pneumatics vs. hydraulics by force, speed, precision needs.
- Guides & Bearings: Linear rails, bushings, ball screws—sized for load and life.
- Tooling & Fixturing: Quick-change modular vs. dedicated hard fixtures; datum references.
4. Control System & Integration
- Controller Platform: PLC vs. PC-based control, I/O count, network protocols (Ethernet/IP, Profinet, OPC-UA).
- HMI & Recipe Management: Touch-screen logic, change-over recipes, operator access levels.
- Data & Traceability: MES/ERP connectivity, OEE logging, SPC feeds, barcode/RFID readers.
- Vision & Sensors: Location of cameras, force/torque, pressure, temperature, proximity switches.
5. Safety & Compliance
- Risk Assessment: Hazard analysis per ISO 12100; PL requirements per ISO 13849-1.
- Guards & Interlocks: Fixed panels, light-curtains, safety mats, door locks.
- E-Stops & Safe-Stop Modes: Emergency-stop placement, functional safety circuits, category rating.
- Standards Alignment: IEC 60204-1, ISO 14120, ANSI B11.x or local machinery directives.
6. Ergonomics & Human Factors
- Operator Interaction: Reach zones, control panel height, viewing angles.
- Material Handling: Lift assists, conveyors vs. manual loading, weight limits per cycle.
- Maintenance Access: Tool-less panels, component placement for quick swap-outs.
7. Reliability & Maintainability
- Component Selection: MTBF/MTTR targets, industrial-grade motors, cables, connectors.
- Preventive-Maintenance Points: Lubrication ports, filter changes, sensor calibrations.
- Diagnostics & Alarms: Auto-fault detection, remote-access capability, event logging.
8. Modularity & Scalability
- Future Expansion: Extra I/O, open architecture, space for add-on modules.
- Quick Change-over: Interchangeable end-effectors, recipe-driven setpoints.
- Standardization: Reuse of proven subassemblies, common parts across machines.
9. Utilities & Environmental
- Power & Air: Voltage, phase, pneumatic flow/pressure requirements.
- Climate & Clean-down: IP rating for wash-down, dust or chemical exposure.
- Noise & Vibration: Isolation mounts, enclosure requirements, plant comfort.
10. Cost & ROI Analysis
- Bill of Materials & Lead Times: Price vs. performance trade-offs, vendor reliability.
- CapEx vs. OpEx: Energy consumption, labor savings, scrap reduction.
- Payback Horizon: NPV or simple‐payback calculation based on throughput gains.