Developing an electric pressure cooker prototype requires precise CNC machining to validate design rationality, funzionalità di prova (PER ESEMPIO., pressure sealing), and evaluate appearance—critical steps before mass production. Unlike regular kitchen appliances, electric pressure cookers have strict requirements for sealing performance E forza strutturale, which shape every stage of the CNC process. This guide breaks down the full workflow, Dal design alla post-elaborazione, with key parameters, scelte materiali, e consigli pratici per garantire il successo del prototipo.
1. Preparazione preliminare: Progetto & Data Processing
The foundation of a high-quality prototype lies in accurate design and optimized data. This stage focuses on creating a detailed 3D model and preparing it for CNC machining.
(1) 3D Modellazione con software CAD
Use professional CAD tools (PER ESEMPIO., Solidworks, E) to design a model that reflects every critical detail of the electric pressure cooker. The model must include both external and internal structures, plus process features to simplify machining.
Structure Category | Key Design Details | Requisiti di precisione | Scopo |
External Structure | Lid (curved top), Posso corpo (cylindrical shape), maniglia (presa ergonomica), pulsanti di controllo (凸起 height ≥2mm) | Lid-body alignment tolerance ±0.1mm; handle mounting hole position error ≤0.05mm | Ensure assembly accuracy; meet user ergonomics |
Struttura interna | Sealing ring groove (width 5mm ±0.05mm), pressure valve mounting seat, sensor fixing holes | Sealing groove depth tolerance ±0.03mm; valve seat hole diameter error ≤0.02mm | Guarantee pressure tightness; fit internal components (PER ESEMPIO., sensori) |
Process Features | Draft slope (3°~5° on lid/pot body), rounding corners (R2mm on handle edges), parting lines | Draft slope ensures easy demolding; rounding prevents stress concentration | Simplify CNC machining; avoid prototype damage during testing |
(2) Model Repair & Format Conversion
Raw 3D models often have defects that can ruin machining—fix these issues before exporting:
- Defect Checking: Use software like Magics to identify broken surfaces, geometria sovrapposta, or missing features (PER ESEMPIO., incomplete sealing grooves).
- Repair Steps: Fill gaps, merge overlapping surfaces, and smooth uneven edges to ensure the model is “machinable.”
- Format Export: Convert the repaired model to Formato stl (the standard for CNC machining), with a mesh density of 0.1mm (balances detail and file size).
2. Selezione del materiale & Processing Process Planning
Choosing the right materials and processes is critical—materials must mimic the performance of mass-produced parts, while processes need to balance precision and cost.
(1) Prototype Material Selection
Different components of the electric pressure cooker require materials with specific properties (PER ESEMPIO., Resistenza al calore, resistenza all'usura). Di seguito è riportato un confronto dettagliato:
Tipo di materiale | Applicable Parts | Proprietà chiave | Suggerimenti di lavorabilità | Trattamento superficiale |
Addominali | Posso corpo, coperchio (appearance parts), control button housings | Easy to mill, superficie liscia, basso costo | Use high-speed spindle (10,000–15,000 rpm) per evitare di sciogliersi | Spray matte black paint (adhesion ≥4B standard) to simulate plastic texture |
Nylon (PA) | Parti strutturali interne (PER ESEMPIO., parentesi di sensori, pressure valve covers) | Alta resistenza, resistenza all'usura, Resistenza al calore (fino a 120 ° C.) | Usa gli strumenti in carburo; add cutting fluid to prevent overheating | No treatment needed (naturally wear-resistant) |
Lega di alluminio (6061) | Metal handles, lid holders | Leggero, alta rigidità, resistente alla corrosione | Use high spindle speed (18,000–22,000 rpm) to reduce burrs | Anodizzante (silver-gray, 8–10μm thick) for anti-oxidation + wire drawing |
Transparent Acrylic | Finestre di osservazione (if included) | High light transmittance (≥90%), Aspetto chiaro | Precision cutting with Φ3mm ball-head tool; avoid chipping edges | Polishing with abrasive paste (from coarse 400# to fine 1200#) |
(2) Core CNC Machining Processes
The process combination depends on the part’s shape and function. Below are the key processes and their applications:
Nome del processo | Scenari di applicazione | Parametri chiave & Suggerimenti |
Macinazione CNC | Pot body cavity (depth ≥80mm), lid curved surface, sealing ring groove | Utilizzo “taglio a strati” for deep cavities (0.5mm per layer); use ball-head tool for curved surfaces (RA ≤1,6μm) |
Turning CNC | Round components (PER ESEMPIO., pressure valve knobs, handle shafts) | Velocità del fuso 20,000 RPM; velocità di alimentazione 1,000 mm/min (ensures smooth surface) |
Perforazione & Toccando | Fori di montaggio del sensore (M4 threads), handle fixing holes | Drill Φ3.3mm bottom holes first, then tap (avoids thread stripping); use pecking drilling for deep holes |
EDM di filo | Special-shaped parts (PER ESEMPIO., acrylic observation window frames) | Achieves accuracy ±0.02mm (critical for transparent, visible parts) |
3. Esecuzione di lavorazione a CNC: Passaggi chiave & Parametri
Precise execution is essential to avoid defects like poor sealing or structural weakness. Focus on programming, Selezione degli strumenti, and process monitoring.
(1) Programmazione & Selezione degli strumenti
Usa il software CAM (PER ESEMPIO., Mastercam, PowerMill) to convert STL models into G-code, and select tools based on material and feature:
Stadio di lavorazione | Tipo di strumento | Tool Size | Impostazioni chiave |
Ruvido | Flat-bottom end mill | Φ10mm (ABS/nylon), Φ8mm (lega di alluminio) | Rimuovere 90% di materiale; leave 0.3mm finishing allowance |
Semifinishing | Ball-head end mill | Φ6mm | Smooth curved surfaces; reduce allowance to 0.1mm |
Finitura | Small ball-head end mill | Φ3mm (ABS/nylon), Φ2mm (acrilico) | Machine fine features (PER ESEMPIO., sealing grooves); achieve Ra ≤1.0μm |
Perforazione | Twist drill | Φ2–Φ5mm | Pecking drilling (drill 3mm, retract 1mm) to clear chips |
(2) Machining Parameter Setting
Parameters vary by material to ensure quality and efficiency. Below is a practical reference:
Materiale | Stadio di lavorazione | Velocità del fuso (RPM) | Velocità di alimentazione (mm/min) | Profondità di taglio (mm) |
Addominali | Ruvido | 10,000–12,000 | 1,500–2.000 | 0.5–1.0 |
Addominali | Finitura | 15,000–18,000 | 800–1.200 | 0.1–0,3 |
Lega di alluminio | Ruvido | 12,000–15,000 | 1,200–1.800 | 0.5–0,8 |
Lega di alluminio | Finitura | 18,000–22,000 | 800–1,000 | 0.1–0,2 |
Nylon | Ruvido | 8,000–10.000 | 1,000–1.500 | 0.4–0,8 |
Nylon | Finitura | 12,000–15,000 | 600–800 | 0.1–0,2 |
(3) Machining Process Monitoring
The first prototype (first piece) requires strict monitoring to catch issues early:
- Controlli dimensionali: Pause after roughing to measure critical features (PER ESEMPIO., sealing groove width, lid-body gap) with calipers or a micrometer. Adjust the program if tolerance exceeds ±0.1mm.
- Surface Quality Checks: Inspect for tool marks, Burrs, or melting (common in ABS/nylon). If tool marks are visible, increase spindle speed by 2,000 RPM.
- Clamping Stability: Ensure the part doesn’t shift during machining—use vacuum suction cups for flat parts (PER ESEMPIO., aluminum handles) or custom fixtures for curved parts (PER ESEMPIO., pot lids).
4. Post-elaborazione & Test funzionali
Post-processing enhances appearance and performance, while functional testing validates if the prototype meets design goals—especially critical for pressure cookers.
(1) Trattamento superficiale
Tailor the treatment to the part’s role and material:
Parte | Surface Treatment Steps | Risultato atteso |
ABS Pot Body/Lid | 1. Grind with 600# → 1000# carta vetrata (remove tool marks); 2. Spray primer (30μm di spessore); 3. Spray matte paint (50μm di spessore); 4. Oven cure at 60°C for 2 ore | Paint adhesion ≥4B; no peeling or fading |
Aluminum Alloy Handle | 1. Degrease with isopropyl alcohol; 2. Anodize (form oxide film); 3. Hand-wire draw along the length | Uniform silver-gray color; Nessun graffio |
Acrylic Observation Window | 1. Polish with 400# abrasive paste (remove cutting marks); 2. Polish with 1200# paste (achieve transparency); 3. Clean with lens cleaner | Light transmittance ≥90%; Nessun difetto visibile |
(2) Test funzionali
Assemble internal components (sealing ring, pressure valve, sensor) and simulate real usage:
Tipo di test | Test Method | Pass Standard |
Test di tenuta | Fill the pot with 500ml water, close the lid, and pressurize to 100kPa (simulate working pressure). Hold for 30 minuti. | No water leakage; pressure drop ≤5kPa in 30 minuti |
Button Feel Test | Press control buttons 1,000 volte (2 presses/second). Measure stroke (2mm ±0.2mm) and feedback force (5–8N). | Consistent stroke and force; no button jamming |
Structural Strength Test | Apply 5kg load to the lid (simulate accidental pressure). Hold for 10 minuti. | No deformation; lid-body gap remains ≤0.1mm |
Heat Resistance Test | Heat the pot to 100°C (simulate cooking) and hold for 2 ore. Cool to room temperature. | No material warping; sealing groove tolerance remains ±0.05mm |
5. Ispezione & Ottimizzazione
Inspect critical dimensions and iterate on the design to fix defects—this ensures the prototype is ready for mold opening.
(1) Critical Dimension Inspection
Usa un Coordinare la macchina di misurazione (CMM) Per controllare le dimensioni chiave:
- Lid-body mating gap: ± 0,1 mm (garantisce la tenuta)
- Sealing ring groove width: 5mm ±0.05mm (fits standard sealing rings)
- Threaded hole position (sensor mounting): ± 0,05 mm (avoids assembly interference)
- Handle mounting hole alignment: ≤0.03mm (ensures handle stability)
(2) Iterazione di progettazione & Ottimizzazione dei costi
If defects are found (PER ESEMPIO., leakage, button jamming), modify the 3D model and reprocess. Use these tips to reduce costs:
- Split Complex Parts: Machine the lid and its holder separately instead of as one piece—cuts machining time by 30% and reduces tool wear.
- Use Hybrid Processes: 3D print small internal parts (PER ESEMPIO., pressure valve covers) with SLS nylon, then CNC machine appearance parts (PER ESEMPIO., Posso corpo) with ABS—lowers material waste by 25%.
- Batch Machining: Per 10+ prototipi, use aluminum profile blanks (pre-cut to approximate size) instead of full blocks—reduces material removal by 40%.
Yigu Technology’s Perspective on Electric Pressure Cooker Prototype CNC Machining
Alla tecnologia Yigu, Crediamo sealing performance and structural strength are the core of electric pressure cooker prototype machining. Many clients overspend by using high-cost materials for non-critical parts—e.g., aluminum alloy for internal brackets that only need nylon. Our team selects materials strategically: ABS for appearance parts (economico, easy to finish) and nylon for internal structures (resistente al calore, resistente all'usura). We also optimize machining for sealing: Nostro “layered finishing” of sealing grooves ensures Ra ≤0.8μm, and we test tightness three times during production to avoid leakage. Per risparmi sui costi, we use hybrid CNC + 3D printing and batch processing, cutting prototype costs by 20–30%. Our goal is to deliver prototypes that accurately validate design and function, accelerating clients’ path to mass production.
Domande frequenti
- Why is nylon (PA) used for internal structural parts instead of ABS?
Nylon has better heat resistance (fino a 120 ° C.) and wear resistance than ABS—critical for internal parts near heating elements or moving components (PER ESEMPIO., pressure valves). ABS melts at ~90°C and wears faster, making it unsuitable for parts that need to withstand high temperatures or repeated use.
- How do you ensure the lid and pot body have a tight seal after CNC machining?
We focus on two key steps: 1) Machining the sealing groove with a Φ3mm ball-head tool to achieve Ra ≤0.8μm (smooth surface reduces leakage risk); 2) Inspecting the lid-body gap with a CMM to ensure tolerance ±0.1mm. We also test tightness with 100kPa pressure—only prototypes with ≤5kPa pressure drop pass.
- How long does it take to CNC machine a single electric pressure cooker prototype?
Total time is ~4–6 days: 1 giornata per la progettazione/elaborazione dati, 1–2 giorni per lavorazione CNC (varies by part complexity), 1 giorno per post-elaborazione (painting/anodizing), and 1–2 days for assembly/functional testing. Produzione in lotti (10+ prototipi) can be shortened to 3–4 days with parallel processing.