Prototyping Strategy

3D print → urethane
→ rapid tooling
→ production.

Smart prototyping uses the right process at each stage. Start with 3D print for concept, move to urethane for functional validation, rapid tooling for market test, steel tooling for production. Each step validates before bigger investment.

Free DFM Review Low-volume production

01 · Stages

The prototype progression.

Stage 1: concept

3D print (SLA/MJF)

1-5 units. Visual and ergonomic validation. SLA for fine detail + looks, MJF for functional feel. Lead time 2-5 days. Cost $50-500 per unit.

Stage 2: functional

CNC or urethane

5-50 units. Mechanical testing, fit verification, failure analysis. CNC for metal/engineering plastic, urethane casting for production-like plastic. Lead time 1-3 weeks. Cost $100-2,000 per unit.

Stage 3: pilot

Rapid tooling / MJF

50-500 units. User testing, regulatory samples, pilot market. Aluminum injection tooling (14 days, 5-20K shot life) or MJF 3D printing. Cost $3,000-15,000 setup.

Stage 4: production

Steel tooling

5,000+ units. Commercial production. Steel injection tool (6-10 weeks, 500K+ shots) or high-volume CNC. Cost $20,000-100,000 tooling.

Skip stages?

When OK

Low-risk designs can skip stages. Proven design similar to existing product: skip concept, go direct to pilot. High-risk or novel: move through all stages — investment de-risking.

Iteration per stage

How many loops

Each stage typically has 1-3 design iterations. Concept: many quick iterations. Functional: validate then refine. Pilot: minor refinements. Production: no changes (tool expensive to modify).

02 · Process selection

Match process to goal.

Goal	Best process	Quantity	Time	Cost per part
Look and feel	SLA 3D print	1-10	2-4 days	$30-300
Functional test (plastic)	MJF 3D print	1-50	3-7 days	$30-200
Functional test (metal)	CNC machining	1-50	5-14 days	$50-1,000
Production-grade plastic	Urethane casting	10-50	2-3 weeks	$30-300
Production-grade plastic	Rapid injection	100-5,000	4-5 weeks	$3-30
Long-life plastic parts	Production tooling	5,000+	8-12 weeks	$0.50-5
Complex metal geometry	DMLS 3D print	1-50	2-3 weeks	$500-5,000
Production metal parts	CNC production	50-10,000	3-6 weeks	$10-200
Visual anatomy	PolyJet 3D print	1-20	3-5 days	$100-2,000
Multi-material	PolyJet 3D print	1-20	4-7 days	$200-3,000

03 · Common pitfalls

Prototyping mistakes we see.

Mistakes

• Building production tool before prototype validation
• Testing FDM prototype as if it represents injection molded part
• Skipping functional prototype stage to save time
• Using 3D printed parts for fatigue or durability testing
• Single prototype when variation testing is needed
• Ignoring DFM feedback from prototype manufacturing
• Over-investing in prototype tool that's close to production tool cost
• Prototyping in wrong material (will not match production behavior)

Best practice

• Plan complete prototype program before starting
• Budget 15-25% of total program cost for prototyping
• Use production material for functional validation
• Multiple prototypes to capture variation
• Document learning from each prototype
• Apply DFM improvements at each stage
• Skip stages only with justification
• Don't over-design prototypes — focus validation on specific questions

04 · Cost perspective

What prototyping actually costs.

Typical prototype budget by program size: Small consumer product (projected 10K units lifetime): $5,000-15,000 prototype investment. Medium consumer product (100K units): $15,000-50,000. Complex consumer product or medical device (50K+ units with regulation): $50,000-200,000. Industrial equipment (low volume, high complexity): $30,000-150,000. These are rough guides — actual depends on complexity, validation requirements, regulatory.

Value of iteration: Design issues caught at concept stage cost $500-2,000 to fix (change CAD, reprint). Same issue caught at pilot production: $5,000-20,000 (modify aluminum tool, rebuild test fixtures). Caught at production: $50,000-500,000 (modify steel tool, recall parts, schedule delays). Each stage catches issues 10× cheaper than next stage.

Time value: Prototype stages take time. Concept 1-2 weeks. Functional 2-4 weeks. Pilot 4-8 weeks. Production 8-16 weeks. Total 16-30 weeks typical for thorough program. Rushing stages compromises validation — may succeed, often causes expensive rework. For market-window-critical products, consider parallel tracks: continue design iteration while production tool builds.

When to invest more in prototypes: Novel technology, untried combinations, regulatory pathway, safety-critical, high production tool cost, long lead time for production tool. Investment in prototyping is cheap insurance against expensive production problems.

When to invest less: Evolution of existing product, proven design approach, low production tool cost, market validated, simple design. Minimal prototyping acceptable — maybe just 1 functional prototype before production.

Our role: We partner through complete prototype programs. Same shop, same designers, same quality system from concept through production. Reduces handoff risks. Our experience with specific processes lets us recommend the right process at each stage — avoids typical prototype strategy mistakes.

FAQ

Can I skip to CNC prototype?

For simple designs that are refinements of existing products: yes. Skip 3D printing, go directly to CNC prototype for functional validation. For complex novel designs: 3D print first for rapid iteration, then CNC prototype for functional validation. The 3D print stage takes $500-2,000 and 1 week — usually cheap insurance to catch obvious issues before more expensive CNC work.

How many prototypes at each stage?

Concept stage: 3-10 iterations typical, might be 1-3 units per iteration. Functional stage: 5-20 units across 1-3 iterations. Pilot stage: 100-500 units for user testing, regulatory, market trial. Production stage: no prototypes, but first articles from production tooling for approval. More prototypes at concept stage (cheap, learn fast), fewer at later stages (expensive, specific validation questions).

When should we involve manufacturing?

From the start. DFM (Design for Manufacturability) feedback is most valuable early — changes are cheap. By concept stage CAD, manufacturing should review for obvious issues. By functional prototype, DFM should be driving design decisions. By pilot, design should be production-ready. Late-stage DFM feedback requires redesign at maximum cost. Our practice: free DFM review on all quote requests.

What about regulatory prototypes?

Medical device, aerospace, automotive regulatory processes often require specific prototype stages. Medical device: design freeze samples for FDA 510(k), clinical trial samples. Aerospace: qualification test articles. Automotive: pre-production samples for PPAP. These have specific documentation requirements — work with customer on specific regulatory path. We support with appropriate documentation and traceability.

Prototype vs production quality?

For most prototypes, production quality not required — validation is the point, not perfect parts. Exceptions: (1) Regulatory prototypes (must match production quality). (2) Customer-facing demos (represent final product appearance). (3) Performance testing (must behave like production). For engineering validation, good enough prototypes are faster and cheaper — don't over-engineer prototypes.

How long for complete prototype program?

Simple consumer product: 3-6 months from concept to production-ready. Complex consumer or industrial: 6-12 months. Medical device with clinical trial: 2-3 years. Aerospace component: 2-5 years. Simple engineering prototype: 4-8 weeks. Quote expected timeline for your specific needs — we can often suggest timeline optimizations.