Form & Appearance
See the design before committing to the next stage.
Evaluate shape, proportions, visible details and surface appearance with a physical model.
Focus on: Overall geometry, colour, texture, finishing and presentation quality.
Custom Rapid
Prototypage
Metal and plastic prototypes built around what you need to validate.
GPT Precision manufactures custom prototype parts for design reviews, assembly checks and functional evaluation. From CNC machining and 3D printing to sheet metal fabrication and selected molding processes, we help match the manufacturing approach to your part geometry, material requirements and testing objectives.
Whether you need a single evaluation part or a small batch before production, start with your drawings and tell us what the prototype needs to prove.
Start with What Your Prototype Needs to Prove
The right prototype is not necessarily the one made with the fastest process. It is the one that provides useful evidence for your next design decision.
Different evaluation goals call for different materials, manufacturing methods and levels of inspection.
Fit & Assembly
Check how components connect and fit together.
Use prototype parts to evaluate mounting features, hole positions, mating surfaces, clearances and assembly sequences.
Focus on: Dimensions critiques, datums, alignment, fastening features and interfaces.
Function & Performance
Evaluate the features that determine how the part works.
Select suitable prototype materials and processes to support mechanical, thermal or application-specific testing under defined conditions.
Focus on: Material properties, loading conditions, movement, dimensional stability and operating environment.
A prototype is only as representative as its material, geometry and manufacturing process allow. Any differences from the intended production part should be considered when evaluating results.
Choose the Right Prototype Manufacturing Process
Different manufacturing routes offer different advantages in material selection, geometry, surface finish, dimensional control and cost.
GPT Precision reviews your part requirements and expected quantities to help identify a suitable approach.
CNC Prototyping
Precision metal and plastic parts with critical functional features.
CNC machining is suited to prototypes requiring specified material grades, controlled dimensions, mating surfaces and machined features.
Typical parts include housings, brackets, shafts, mounting components and mechanical assemblies.
Best suited for: Assembly trials, material evaluation and dimensionally controlled functional samples.
Key considerations: Material grade, machining access, critical tolerances, surface finish and inspection requirements.
Machined samples may behave differently from parts manufactured by molding or forming, even when their nominal geometry is similar.
Explore CNC Prototyping →3D Printing
Complex geometries and flexible design iterations.
Additive manufacturing builds components layer by layer, making it useful for concept models, fit checks, design iterations and selected functional prototypes.
SLA, SLS, FDM and PolyJet offer different combinations of detail, surface quality, material characteristics and appearance.
Best suited for: Early design evaluation, complex features, presentation models and selected engineering tests.
Key considerations: Printing process, material properties, build orientation, surface finish and test conditions.
Explore 3D Printing →Vacuum Casting
Small batches of plastic-like prototype parts.
Vacuum casting reproduces detailed shapes using a master pattern and a flexible mold. It can support appearance reviews, assembly evaluation and selected functional tests when several similar samples are needed.
Best suited for: Small-batch design samples, appearance models and selected assembly evaluations before production tooling.
Key considerations: Casting resin, mold life, quantity, dimensional behavior and material limitations.
Vacuum-cast materials should not be assumed to perform identically to specified production injection-molding grades.
Sheet Metal Prototyping
Functional brackets, enclosures and formed components.
Sheet metal fabrication uses cutting, bending and related operations to produce prototype parts for evaluating geometry, mounting features and assembly relationships.
Best suited for: Enceintes, brackets, panels, mounting structures and formed metal parts.
Key considerations: Material grade, sheet thickness, bend radii, hole positions, joining methods and finish.
The forming approach used for prototypes may differ from the process selected for higher-volume production.
Explore Sheet Metal Fabrication →From Prototype Parts to Molded Samples
As a plastic product moves closer to production, evaluation may need to shift from machined, printed or cast prototypes to parts made by an intended molding process.
Tooling decisions should consider design maturity, material requirements, expected quantities and the evidence needed before production approval.
Bridge Tooling
Molded parts before full production tooling investment.
Bridge tooling can support designs that are sufficiently mature for molded-part evaluation, limited initial production or interim supply while longer-term tooling is being planned.
Tool design, cavity arrangement, material requirements, anticipated revisions and expected output influence the appropriate approach.
Review: Tooling investment, production quantity, expected tool life, part requirements and possible design changes.
Injection Molding Trials
Evaluate the part and the molding process together.
Molding trials provide physical samples and process information for reviewing dimensional results, appearance, fit and molding-related effects such as shrinkage or warpage.
The first trial is an evaluation step, not automatic approval for production. Depending on the findings, tooling modifications, process adjustments or additional trials may be necessary.
Review: Resin grade, dimensions critiques, exigences de surface, sample acceptance criteria and inspection evidence.
Bridge tooling and injection molding trials are not interchangeable services. Their roles depend on the tooling strategy and validation requirements of the project.
Match Your Prototype to the Development Stage
Prototype requirements change as a product moves from initial concept to manufacturing validation.
The development stage helps define what should be evaluated, how representative the sample needs to be and what evidence is required.
Concept Evaluation
Is the overall design right?
Review form, dimensions, handling, appearance and early assembly concepts.
The priority is identifying design issues and gathering feedback before further engineering work.
Engineering Validation (EVT)
Does the design function as intended?
Evaluate important interfaces, assembly relationships, mechanical behavior and defined functional requirements.
Materials and processes should be appropriate for the tests being performed.
Design Validation (DVT)
Does the design meet its specified requirements?
Review performance criteria, material suitability, dimensional requirements, finishes and the required validation evidence.
Identify where production-representative samples are necessary.
Production Validation (PVT)
Can the intended manufacturing process produce acceptable parts consistently?
Evaluate production tooling, process conditions, pilot quantities, inspection methods and acceptance results.
Successful prototype testing alone does not establish production readiness.
EVT, DVT and PVT terminology and approval practices vary between organizations. The applicable validation plan, test responsibilities and acceptance requirements should be defined for each project.
Define the Features That Matter
Inspection should reflect the purpose of the prototype.
An appearance model may need only selected visual and dimensional checks. An assembly or functional prototype may require closer evaluation of specific features.
Identify the characteristics that determine whether the sample is useful for its intended evaluation.
Part inspection and functional validation are different activities. Dimensional inspection verifies specified characteristics of the manufactured component. Functional testing evaluates whether the design performs as intended under defined conditions.
Test responsibilities and any additional evidence requirements should be confirmed as part of the project scope.
Critical Dimensions
Specify the dimensions, datums and geometric relationships that control fit, alignment, movement or function.
Material Requirements
Identify the required material grade, relevant properties and any acceptable alternatives. Material substitutions should be considered in relation to the intended tests.
Surface Requirements
Define the required finish, texture, colour and functional surface characteristics, including any critical cosmetic areas.
Inspection & Acceptance
Agree on critical measurement features, inspection methods, acceptance criteria and any required reports before manufacturing.
Plan Your Prototype and Production Requirements Together
The best process for a prototype may not be the best process for production.
A single design may move through several manufacturing methods as quantities, materials and validation requirements change.
Sharing your immediate prototype needs and expected future demand helps identify a suitable approach for each stage.
For Your Prototype
Provide the information needed to manufacture and evaluate the current design:
- Current 3D models and available 2D drawings
- Drawing revision and evaluation objectives
- Required sample quantity
- Material grade or preferences
- Critical dimensions and surface requirements
- Inspection and documentation needs
- Target delivery date
For Future Production
If production is planned, also include:
- Expected batch quantities and order frequency
- Intended production material and process
- Anticipated design changes
- Tooling requirements, where applicable
- Quality and acceptance expectations
- Packaging and delivery requirements
These details help assess whether the prototype approach can continue into production or whether changes in tooling, process or material will be necessary.
From Drawing Review to Prototype Delivery
Share Your Requirements
Send your drawings or 3D models with the sample quantity, material preference, evaluation objectives and target date.
Identify critical features and any required inspection documents.
Review the Manufacturing Approach
We assess process suitability, material requirements, geometry and manufacturing considerations.
Technical questions affecting the proposed approach, cost or quotation scope are reviewed before proceeding.
Confirm the Project Scope
Agree on the drawing revision, manufacturing method, matériau, finish, critical requirements, inspection scope and delivery arrangements.
Quotation timing and manufacturing lead time depend on part complexity, matériau, quantity and the engineering review required.
Manufacture, Inspect & Evaluate
Prototype parts are manufactured and inspected according to the agreed requirements.
Use the completed samples and evaluation results to determine whether further changes, additional prototypes or production-stage planning are needed.
Foire aux questions
Which rapid prototyping process should I choose?
Start with what the prototype needs to demonstrate, along with its geometry, material requirements and quantity. CNC machining, 3D printing, vacuum casting and sheet metal fabrication serve different purposes. You can submit drawings without selecting a process first.
Do prototypes need to use the final production material?
Not always. Alternative materials may be suitable for appearance models and some initial fit checks. Functional tests that depend on mechanical, thermal, chemical or other material properties may require the specified grade or an appropriately representative material.
Can I combine different manufacturing processes in one prototype project?
Depending on the design, an assembly may contain parts manufactured using different processes. For example, machined components may be combined with printed or sheet metal parts. The manufacturing and inspection requirements should be defined for each component.
Can vacuum-cast samples replace injection-molded parts?
Vacuum-cast samples can support appearance, assembly and selected evaluations. However, casting resins and processes may not reproduce the behavior of production injection-molding materials. Tests requiring production-material or process representation may need actual molded samples.
Can I order prototypes before finalizing production quantities?
Yes. Prototype quantities can be evaluated separately from future production demand. Sharing an estimated production quantity is useful because it may influence process selection, tooling strategy and the approach to later manufacturing stages.
How are quotation timing, lead time and inspection requirements determined?
These depend on the drawings, matériau, manufacturing process, quantity, complexity and required engineering review. Les méthodes d'inspection, documentation and delivery expectations are agreed according to the project requirements. The expected quotation timeline is communicated after the initial review.
Ready to Evaluate Your Next Design?
Start with your drawings. Tell us what the prototype needs to prove.
Whether you need a concept model, a functional metal or plastic component, an assembly sample or a prototype that supports the next manufacturing decision, GPT Precision can help review the appropriate manufacturing approach.
Send your current drawings, required quantity, material preferences, critical features and target date. Include expected future production quantities if available.
