Quel est le processus professionnel de prototype informatique d'usinage CNC?

cnc shaping

1. Usinage pré-CNC: Preparation and Design for Computer Prototypes

Before launching Usinage CNC for the computer prototype, a systematic preparation and design stage is critical to align with functional, de construction, and production needs. Cette étape suit une séquence linéaire, avec des détails clés organisés dans le tableau ci-dessous.

Étape de conceptionExigences clésMatériaux recommandés
Analyse de la demande de produitsClarify computer type (desktop/laptop), taille (Par exemple, laptop: 350×250×15mm; desktop case: 400×300×200mm), and functional layouts: Reserve space for motherboard (ATX/Micro-ATX), CPU cooler, hard drive, power supply, et ports (USB, HDMI, Ethernet); Ensure structural support for heat dissipation (fan mounting holes, vent slots) and component stability.
Part SplittingDivide the computer model into machinable components: Laptop upper/lower shells, keyboard bezel, screen back cover; Desktop case panels (front/top/side), supports internes (motherboard tray, hard drive holder). Avoid overhangs or closed cavities that hinder CNC machining.
3D ModélisationUtiliser le logiciel CAO (Solide, Et nx) to create 3D models with precise dimensions. Highlight critical features: Screw holes (M3-M4 for case panels), port cutouts (USB Type-C: 8.4×2.6mm), fan mounting slots (120mm/92mm standard size), and motherboard standoff positions (tolérance ± 0,05 mm). Add 3°-5° draft slopes for future mold compatibility.
Sélection des matériauxChoose materials based on part function, machinabilité, et coûter. Prioritize compatibility with mass production processes.Laptop Shells/Desktop Panels: Plastique abs (faible coût, résistant à l'impact, Facile à teindre); Internal Brackets (Motherboard Tray): Alliage en aluminium (forte résistance, good heat conduction); Transparent Side Panels (Bureau): Acrylique (clair, résistant aux rayures); Keyboard Bezel: Plastique PC (rigidité élevée, à l'usure).
Prétraitement des matériauxCouper les matières premières en flans (leave 2-3mm machining allowance): For plastic sheets, Utiliser la coupe laser; For aluminum alloy blocks, use bandsaw cutting. Alliage d'aluminium recuit (300-350° C pour 1-2 heures) Pour réduire le stress interne; Nettoyez tous les blancs avec de l'alcool pour enlever l'huile et la poussière.

2. Core CNC Machining Process for Computer Prototypes

Le Processus d'usinage CNC is the bridge between 3D models and physical prototype parts. It requires strict control over programming, clamping, and cutting to ensure precision and structural reliability.

2.1 CAM Programming and Toolpath Design

Scientific programming determines machining efficiency and part quality. The table below outlines key steps and parameters:

Programming StepActions clésLogiciel recommandé & Outils
Importation de modèle & Coordinate SetupImport 3D models (STEP/IGS format) into CAM software; Set machining origin (align with part center for symmetrical components like desktop side panels).Mastercam, Moulin électrique
Génération de parcours d'outilBrouillage: Utiliser des outils de grand diamètre (φ10-12mm flat cutters) to remove 80-90% en excès de matériau; Leave 0.5-1mm finishing allowance.- Finition: Utiliser des outils de petit diamètre (φ0.5-1mm ball cutters) pour plus de détails (port cutouts, fan slots, logo grooves); Set cutting depth to 0.1-0.2mm per pass.- Corner Cleaning: Use φ2-3mm end mills to remove residue in complex areas (Par exemple, motherboard standoff holes, USB port edges).– Brouillage: Acier à grande vitesse (HSS) couteaux- Finition: Carbide cutters
ParamètreAdjust rotational speed, taux d'alimentation, and cutting depth based on material:
– Alliage en aluminium: 8000-10000 RPM, 300-500 Taux d'alimentation MM / Min- Plastique abs: 4000-6000 RPM, 200-300 Taux d'alimentation MM / Min- Acrylique: 5000-7000 RPM, 250-350 Taux d'alimentation MM / Min

2.2 Clamping and Machining Execution

Proper clamping prevents part displacement, while precise execution ensures dimensional accuracy.

2.2.1 Clamping Guidelines

  • Sélection des luminaires:
  • Use vises with soft jaws (rubber-coated) for aluminum alloy blocks to avoid surface scratches.
  • Use vacuum suction cups for thin plastic sheets (Par exemple, 2-3mm laptop keyboard bezel) to ensure even pressure and prevent deformation.
  • Use custom jigs for irregular parts (Par exemple, laptop screen back cover with curved edges) to maintain alignment during machining.
  • Symmetrical Part Handling: For desktop front/top panels, use double-sided clamping (machine one side, flip, and re-calibrate with a probe) to ensure left-right symmetry (error ≤±0.05mm).

2.2.2 Machining Execution Steps

  1. Brouillage: Focus on speed—use layer-by-layer milling to shape the part’s basic outline (Par exemple, laptop shell edges, desktop case openings). Pour les pièces en plastique, control cutting force (max 40N) Pour éviter de craquer; pour alliage d'aluminium, use cutting fluid to reduce heat-induced deformation.
  2. Finition: Prioritize precision—machine critical features first (port cutouts, trous à vis, fan slots). For threaded holes (M3-M4), use taps (pour le plastique) or thread milling cutters (pour le métal) to ensure smooth screw installation (no cross-threading).
  3. Traitement spécial:
  • Use 4-axis linkage machining for curved surfaces (Par exemple, laptop palm rest edges) to achieve consistent curvature (error ≤±0.1mm).
  • For acrylic transparent panels, use high-speed finishing (10000 RPM) to maintain surface clarity (no visible machining marks).

2.3 Quality Inspection During Machining

Conduct in-process checks to catch defects early:

  • Inspection dimensionnelle: Use digital calipers (for outer dimensions, tolérance ± 0,1 mm) and micrometers (for aluminum alloy brackets, tolérance ± 0,01 mm) after each process.
  • Surface Quality Check: Use a stylus roughness meter to verify surface finish (Ra ≤1.6μm for visible parts like laptop shells; Ra ≤3.2μm for internal brackets).
  • Feature Verification: Use go/no-go gauges to test port cutouts (Par exemple, USB Type-C gauge) and screw holes (ensure screws fit smoothly without force).

3. Après l'achat: Surface Treatment and Finishing

Après l'usinage CNC, targeted surface treatment enhances the prototype’s appearance, durabilité, and user experience.

3.1 Deburring and Polishing

  • Débarquant:
  • Use 400-mesh sandpaper to remove machining burrs on plastic parts; pour les pièces métalliques, use a round file (Pour les trous) and flat file (pour les bords) to eliminate sharp corners.
  • Utilisez de l'air comprimé (0.5-0.8 MPA) to blow out debris from small holes (Par exemple, motherboard standoff holes) and vent slots.
  • Polissage:
  • For aluminum alloy parts: Use vibration grinding (1-2 heures) to achieve a matte finish; for high-gloss effects, perform mechanical polishing with 800-1200 mesh sandpaper followed by a wool wheel with polishing paste.
  • For acrylic panels: Utiliser 1000-1500 mesh sandpaper for wet sanding, then polish with acrylic-specific polish to restore transparency (light transmittance ≥90%).

3.2 Material-Specific Surface Treatment

Different materials require tailored treatments to meet design goals, as shown in the table:

MatérielMéthode de traitement de surfaceBut & Effet
Alliage en aluminiumSable + AnodisationSable (80-120 mesh grit) creates a uniform matte texture; Anodisation (épaisseur 5-10μm) adds corrosion resistance (salt spray test ≥48 hours) and color options (noir, argent, gris) for desktop brackets.
Plastique absPeinture + Silk ScreenPeinture en spray mate/brillante (2-3 manteaux, dry time 12-24 heures) to match brand colors; silk screen prints brand logos, port labels (Par exemple, “USB 3.0”), and warning text (adhesion test: no peeling after 100 tape pulls).
AcryliqueGravure laser + Anti-Fingerprint CoatingLaser engraving adds patterns (Par exemple, Logos de marque, mesh designs) on transparent panels without affecting clarity; anti-fingerprint coating reduces smudges by 60% for daily use.

4. Assembly and Testing of Computer Prototypes

Scientific assembly and rigorous testing ensure the prototype meets structural and functional requirements.

4.1 Processus d'assemblage

Follow this step-by-step sequence to avoid errors:

  1. Vérification avant assemblage:
  • Utilisez une machine à mesurer de coordonnées (Cmm) to inspect critical dimensions (Par exemple, motherboard tray hole spacing, tolérance ±0,03 mm).
  • Test-fit all parts: Check if the motherboard aligns with standoffs, if ports match cutouts, and if fans fit into mounting slots (gap ≤0.1mm).
  1. Component Installation:
  • Assemblage du logement: Fasten desktop case panels with M3 screws (couple 1.5-2 N · m) to ensure even fit (pas de lacunes); assemble laptop upper/lower shells with snaps (pour le plastique) ou vis (for metal hinges).
  • Internal Brackets: Install motherboard trays, hard drive holders, and fan brackets using screws; ensure brackets are level (tilt ≤0.5°) to prevent component damage.
  • Detail Parts: Attach keyboard bezels, screen back covers, and acrylic side panels; adjust screen hinges (for laptops) to ensure smooth opening/closing (no loose or stuck issues).
  1. Final Check: Verify all parts are securely fastened; shake the prototype gently (laptop: 10° tilt, bureau: 5° tilt) to check for loose components (no rattling).

4.2 Testing Procedures

Conduct comprehensive tests to validate performance:

  • Appearance Inspection:
  • Check color consistency (ΔE ≤1.5) et défauts de surface (no scratches >0.5mm, ≤1 blemish per 100cm²).
  • Verify logo/symbol clarity (pas de bavure) and port label alignment (no misplacement).
  • Structural Testing:
  • Load-Bearing Test: Place a 5kg weight on the laptop palm rest (10 minutes) and desktop top panel (30 minutes); check for deformation (≤0,2 mm).
  • Hinge Durability Test: Open/close the laptop screen 100 fois; check hinge tightness (no looseness) and screen alignment (pas de décalage).
  • Port Reliability Test: Plug/unplug USB/HDMI cables 50 fois; check port stability (no wiggling) and cutout fit (aucune interférence).
  • Vérification fonctionnelle:
  • Install a test motherboard, CPU, and fan; power on to check if components fit (no short circuits) and if fans align with vent slots (airflow unobstructed).
  • Test heat dissipation: Run a stress test for 30 minutes; check if vent slots allow hot air to escape (no heat buildup in critical areas).

5. Optimization and Iteration

Address issues found during testing to improve the prototype:

  1. Problem Logging:
  • Record defects (Par exemple, “Motherboard standoff hole misalignment (0.3MM)”, “Laptop hinge loose after 50 openings”, “Acrylic panel scratch during assembly”) with photos and specific measurements.
  1. Optimisation de conception:
  • Modify 3D models: Adjust standoff positions, thicken hinge mounting areas, or add chamfers (C1) to acrylic panel edges to reduce scratches.
  • Regenerate CAM programs: Update toolpaths for optimized parts (Par exemple, adjust port cutout size to fix cable interference).
  1. Traitement secondaire:
  • Rework defective parts: Re-machine misaligned holes, tighten hinge screws, or polish acrylic scratches with 2000-mesh sandpaper.
  • Replace non-functional components: Swap loose hinges or cracked plastic panels.

6. Output Results and Documentation

Deliver a complete prototype package with useful documentation:

  • Prototypes: Functional computer prototypes (1-10 unités) for demonstrations, user testing, or low-volume trial production.
  • Documents techniques:
  • 3D model files (STEP/IGS) and 2D drawings (Dxf) with dimension annotations.
  • CNC machining programs (Code G) and tool lists (cutter type, diamètre, durée de vie).
  • Assembly drawings (with part numbers, screw torque specs) and inspection reports (CMM data, Résultats des tests).
  • Feedback Report: Summarize challenges (Par exemple, “Aluminum alloy bracket deformed during machining”) and solutions (Par exemple, “Increased annealing time to 2.5 heures”); suggest mass production improvements (Par exemple, “Switch to injection molding for ABS laptop shells”).

7. Précautions clés

To ensure process efficiency and prototype quality:

  • Contrôle de précision: CNC machining accuracy is ±0.05mm, but account for material behavior—aluminum alloy expands (add +0.02mm tolerance), plastic shrinks (ajouter -0.03mm tolerance) Après l'usinage.
  • Solde des coûts: CNC is ideal for small-batch prototypes (1-100 unités); pour la production de masse (>1000 units), use injection molding (plastiques) or die casting (métaux) to reduce costs by 50-70%.
  • Sécurité: Wear safety glasses and gloves during machining; use fume extractors when spraying paint or anodizing to avoid toxic exposure.

Point de vue de la technologie Yigu

À la technologie Yigu, nous croyons CNC machining is the cornerstone of high-quality computer prototype development. It enables precise replication of complex structures (Par exemple, motherboard trays, Hinges d'ordinateur portable) and supports rapid iteration—critical for computer products where structural fit (Par exemple, component alignment, port compatibility) directly impacts usability. When executing this process, we prioritize two core aspects: material-function matching (Par exemple, aluminum alloy for heat-conductive brackets, acrylic for transparent panels) et l'optimisation du processus (Par exemple, 4-axis machining for curved laptop edges, in-process CMM checks to avoid rework). By integrating strict quality control at every stage—from design to testing—we help clients shorten prototype cycles by 20-30% and mitigate mass production risks. Regarder vers l'avenir, we will leverage AI-driven CAM programming to further enhance machining efficiency while maintaining ±0.03mm precision, supporting faster innovation for computer brands.

FAQ

  1. What materials are best for CNC machined computer prototype parts, et pourquoi?

The best materials depend on part function: ABS plastic for housings (faible coût, résistant à l'impact, Facile à teindre); aluminum alloy for internal brackets (forte résistance, good heat conduction); acrylic for transparent panels (clair, easy to engrave); and PC plastic for keyboard bezels (rigidité élevée, à l'usure). These materials balance machinability, fonctionnalité, and compatibility with mass production.

  1. Can a CNC machined computer prototype be used directly for mass production?

Non. CNC prototypes are for design verification, tests fonctionnels, and user feedback—they are not cost-effective for mass production (>1000 unités). For large-scale manufacturing, processes like injection molding (for plastic housings) or die casting (for metal brackets) replace CNC machining, as they reduce per-unit costs by 50-70% and increase production speed by 3-5 fois.

  1. How long does it take to make a CNC machined computer prototype from design to testing?

The timeline depends on complexity: A simple desktop case prototype (ABS panels, supports de base) prendre des prises 8-12 jours (3-4 days design, 3-4 days CNC machining, 1-2 days surface treatment, 1-2 days assembly/testing). A complex laptop prototype (aluminum alloy shell, bords courbes, charnières) prendre des prises 14-18 jours, as it requires more intricate machining and hinge adjustment.

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