Rapid Prototyping
Rapid prototyping turns a CAD file into a real part in days, not weeks. Catch interference, wall thickness issues, and assembly problems before cutting a steel mold or running a production batch
Overview
One CAD file, five process options. CNC machining handles metal prototypes and tight tolerances. 3D printing covers complex geometry and one-off concept models. Vacuum casting copies 10–25 PU parts off a silicone mold. Sheet metal prototyping turns flat patterns into bent brackets and enclosures. Prototype injection molding runs aluminum tools for 50–500 production-grade plastic parts
Different stages need different routes. Concept review goes to 3D printing. Functional testing usually goes to CNC. Market trial samples and pre-production runs go to vacuum casting or prototype injection molding. Picking the wrong route costs time more often than it costs money
Typical Applications
Concept Models
Early visual and tactile models that lock in form, proportion, and styling before any tooling is committed.
Functional Prototypes
Working parts in production-intent materials, built to verify fit, function, and mechanical performance under real loads.
Engineering Validation
Rigorous testing of strength, durability, and environmental resistance to confirm the design meets performance and safety targets.
Fit & assembly testing
Dimensional and mating checks across components to verify tolerances, clearances, and assembly before scale-up.
Market testing samples
Near-final, cosmetically finished units in small batches for customer, retailer, and certification feedback.
Bridge production
Limited pre-mass runs on near-final tooling that keep you shipping while hard tooling and full production ramp up.
Process Flow
Cost Considerations
Process choice drives most of the cost difference. A single 3D printed concept model costs $20–80. The same part as a CNC-machined aluminum prototype runs $150-400. Vacuum-cast in PU resin sits between the two on per-part cost but needs a master pattern upfront. Injection-molded prototypes carry $2,000-5,000 tooling cost spread across the batch.
Cheap prototypes aren’t always cheaper. A $30 FDM part that warps during fit testing wastes two weeks. A $200 CNC part that confirms the design saves the reprint cycle. Match the process to what the prototype actually needs to prove.
Part Geometry and Complexity
Deep cavities, thin walls, and small internal radii drive cycle time more than overall part size
Material Selection
6061 covers 60% of jobs; 7075 doubles the strength but costs more; PEEK only when heat or chemicals demand it
Process Selection
FDM $20-80 per part, CNC $150-400, vacuum casting in between, injection prototypes carry $2k–5k tooling
Quantity
CNC scales linearly with batch size; vacuum casting needs a new silicone mold every 15–25 parts
Surface Finish and Secondary Work
Ra 1.6 μm comes standard; tighter finishes, anodize, paint, and insert installation each add days, not hours
Practical Cost Guidance
Default everything to ISO 2768-m, then call out only the 2–4 features that actually need tight tolerances
Recommended Capabilities
CNC Machining
Rapid Injection Molding
Vacuum Casting
Sheet Metal Fabrication
Additive Manufacturing
Surface Finishing
Related Case Studies
3D Printer Filament Types: Polymer Families, Feedstock Quality, Drying, Printability and Selection
Types of Metals for Manufacturing: Properties, Machinability, Cost and Selection
Shear Modulus for Polymers and 3D-Printed Parts: Formula, Torsion Testing, Dynamic G, and Anisotropy
Ultimate Tensile Strength (UTS): What It Measures and How to Read It on an MTR
Bulk Modulus in Engineering Materials: Compressibility, Elastic Constants, Measurement Limits and Design Use
Tensile Stress in 3D-Printed Parts: Formula, Stress-Strain Data, Anisotropy, Test Methods and Design Limits
Why Work With EPOC CRAFTER
Prototyping shops usually run one or two processes. A CNC house can’t pour PU resin; a 3D print bureau can’t bend sheet metal. Project that needs three different processes ends up split across three vendors, with three lead times and three sets of shipping costs.
Epoc Crafter runs CNC, 3D printing, vacuum casting, sheet metal, and prototype injection molding under one roof. One quote, one project manager, one delivery date. When the bracket needs to ship with the housing and the housing needs to ship with the silicone seal, all three come from the same building
Get Your Prototype Quoted Today
Send a STEP or STL file. We review geometry, flag any DFM issues, and return a quote with process, material, and lead time within 12 hours. Single parts welcome.
Rapid Prototyping: Common Questions
Answers to the questions that come up before most first orders.
Minimum order quantity is 1 for CNC machining and 3D printing. Vacuum casting requires 10 parts per mold pour. Prototype injection molding starts at 50 parts because the aluminum tooling cost needs to spread across a batch. If you need one functional bracket or one concept model, send the file.
STEP and IGES for CNC and vacuum casting. STL or 3MF for 3D printing. DXF or DWG for sheet metal flat patterns. A 3D file alone is enough to quote geometry, process, and lead time. Add a 2D drawing with GD&T callouts only when specific tolerances matter, otherwise our DFM review flags the critical features and we confirm tolerances before starting. Learn more on our DFM Design Guidelines page.
Yes. We sign NDAs before reviewing any file. All uploaded files are stored on access-controlled servers. Engineers working on your project sign confidentiality agreements. Customer files are never shared with third parties or reused as reference geometry for other jobs. See our full data handling policy on the Security & Compliance page.
3D printing ships in 1 to 3 days. CNC machined metal prototypes finish in 1 to 5 days depending on setup count and material. Vacuum casting needs 4 to 6 days for the silicone mold before parts come out. If you have a hard deadline, say so in the quote form and we will check capacity before confirming. Rush jobs are routed to available machines, not queued behind standard orders.
Concept review and form check: 3D printing. Functional testing under real load: CNC machining in aluminum or steel. Market trial samples where finish and material feel matter: vacuum casting in PU resin. Pre-production runs before hard tooling is locked: prototype injection molding. Wrong process for the stage wastes more time than the cost difference. Our Engineering Hub has process selection guides if you need a reference.
CNC parts ship at Ra 1.6 μm as standard. Options include anodizing (clear, hard, color), bead blasting, polishing, painting, powder coating, and plating. 3D printed parts can be sanded, primed, and painted. Vacuum cast parts come in mold texture or can be painted to match production intent. Full options are listed on the Surface Finishing page.
Parts ship DHL, FedEx, or UPS from Shenzhen. Express delivery reaches North America and Europe in 2 to 4 business days. We prepare commercial invoices and HS codes. Duties and import taxes are the buyer’s responsibility and depend on destination country and part value. For orders above 50 kg we arrange air freight. US customers can also route delivery through our North Carolina address to simplify domestic handling.
Wire transfer (T/T), PayPal, and major credit cards. New customers pay before production starts. Established accounts with order history can request net-30 terms. Payment details are confirmed on the quote before any manufacturing begins.
All parts go through dimensional checks on critical features called out in the drawing, plus visual inspection for surface defects. First article inspection reports are included on request. CMM reports with GD&T callout verification are available for tight-tolerance machined parts. Details on the Quality & Certifications page.
