Industry sourcing decision
Product development teams need parts that answer engineering questions, not disconnected samples from whichever process is easiest to request. A fit model, functional prototype, design-verification sample and production-intent component can require different fidelity in material, geometry, finish and evidence. MakeNexa reviews the design package and routes RFQs across a global supplier network. The project team retains design authority, while supplier fit, manufacturability, process, material, tolerances, quantity, inspection, price and lead time are confirmed per RFQ.
Application context
Start with the engineering question. Decide whether the build must verify envelope, mating geometry, mechanism, thermal behavior, sealing, appearance, assembly time or repeat process output. For each question, list the attributes that must be representative and those that may differ. This turns process selection into a deliberate fidelity decision rather than a debate about whether machining, additive manufacturing, sheet fabrication or molding is universally better.
Build a controlled handoff around those decisions. Supply authoritative models and drawings, revision and part relationships, material and finish requirements, interface controls, quantities, acceptance evidence and the team's test plan. Record approved deviations and the reason for them. MakeNexa can coordinate route review and quote clarification, but testing a manufactured sample, approving the design and releasing a later revision remain the product team's responsibilities.
Typical program needs
This route is useful when the team needs to preserve engineering intent while changing process, revision or build objective.
Low-commitment models can evaluate envelope, service access, human factors and component packaging. Define the coordinate references and mating components that must stay stable even when nonfunctional materials or simplified features are used.
Mechanisms, enclosures, thermal paths, seals and structural interfaces need a clear test purpose. Identify which loads, surface conditions, joints and hardware must represent the intended design, and which results remain process-specific.
Matched samples can compare architecture, assembly, surface or manufacturing implications when the comparison holds function constant. Keep evaluation criteria neutral and avoid treating one sample's appearance as proof of production cost or capability.
A released model, drawing, bill of materials, critical-feature list, finish standard and inspection plan create a reusable supplier package. Include open questions and change rules so the handoff remains a controlled engineering conversation.
Application risks
A sequence of individually successful prototypes can still fail to produce a reliable release package.
Representative geometry with substitute material may answer fit but not durability; representative material with a different process may not answer surface or residual-stress questions. State the test and the fidelity needed for that test.
Small shifts in hole patterns, datum surfaces, connector positions or seal grooves can invalidate mating parts. Maintain an interface list and highlight changes rather than relying only on a new file timestamp.
Process comments are most useful when they connect to function, cost driver, evidence or repeatability. Record the proposed change, accepted owner and affected requirements so the next supplier sees the current decision rather than old discussion.
A fit model may need only selected interfaces checked, while a verification or production-intent build may need broader recorded evidence. Align inspection with the question and release stage instead of applying either no control or a full report by habit.
Sourcing paths
A staged plan can reduce unnecessary tooling while still protecting the requirements that must carry forward.
Use flexible additive, machining or fabrication methods for envelope, access and interface checks when production material or surface behavior is not yet required. Clearly mark simplified and nonrepresentative attributes.
Choose representative material, critical geometry, joints and surface state when the team is testing motion, sealing, thermal, load or wear behavior. Define team-owned test conditions and supplier acceptance separately.
Use the intended process family, stable revision, controlled supplier package and evidence plan when the team needs repeat output or manufacturing validation. Review tooling, fixtures, process changes and acceptance records as part of the RFQ.
Program decision table
Typical published values for the routes common in product development work. Achievable results depend on the specific part and supplier, and the project requirement is confirmed on the reviewed quote rather than from this table.
| Decision layer | Typical published value | Routing consequence |
|---|---|---|
| FDM printing | ±0.2 mm or ±0.2% accuracy, interlayer strength at only 30 to 70% of the in-plane value, Ra 10 to 25 µm | Form and fit checks, not structural tests |
| SLA printing | ±0.1 mm or ±0.1% accuracy with Ra 1 to 5 µm surfaces, but heat-deflection near 50 °C and creep under sustained load | Appearance models and masters, not functional parts |
| SLS and MJF | ±0.3 mm or ±0.3% in PA12 at about 48 MPa with 15 to 20% elongation, isotropic enough for functional testing | Functional polymer parts without tooling |
| CNC machining | ±0.125 mm standard practice in the actual production material, isotropic properties | The route when material behaviour is what is being tested |
| What only moulding gives | Knit lines, fibre orientation, shrinkage from 0.5% for ABS to 2.5% for acetal, and living hinges | Which conclusions require a moulded part |
| Material substitution | 6061 at 276 MPa yield for 7075 at 503 MPa, acetal for PEEK — fine for fit, invalid for strength | State what the prototype must prove |
| Tolerance on a prototype | ±0.125 mm block with ±0.025 mm only on features under test | Blanket production tolerances price a prototype as a production part |
| Finish on a prototype | As-machined at Ra 1.6 to 3.2 µm away from the surfaces being evaluated | Cosmetic finishing on a functional prototype is spend without learning |
| Finishing effect on fit | Powder adds 50 to 100 µm per surface and anodize 5 to 25 µm — enough to invalidate a fit check | Whether the prototype is finished, and whether that matches production |
| Cost at low quantity | At 1 to 10 parts, setup dominates; a second part often costs a fraction of the first | Ordering a spare is usually cheap insurance |
| Design cost drivers | Pocket depth under about 4 times cutter diameter, internal radii above 1 mm, walls above 0.8 mm | Visible in the model before quoting |
| Preserving supplier feedback | Supplier-identified process-critical features — thin walls, re-fixtured relationships, unreachable burrs — returned to the design | Often the highest-value output of a first RFQ |
Industry RFQ inputs
Explain what the build must teach and which design requirements must survive the selected route.
Complete packages move faster: revision-matched CAD, critical dimensions, quantity and material notes are enough to open engineering review across the network.
Get a QuoteState the engineering question, build stage and intended test or review outcome
Submit controlled models, drawings, revision, BOM and relevant mating geometry
Mark required geometry, material, process, surface and assembly fidelity
Identify critical interfaces, datums, purchased components and keep-out zones
Provide quantities, variants, next-stage assumptions and acceptable alternatives
Define supplier inspection, team testing, evidence records and deviation handling
Record open design decisions, change ownership and the intended manufacturing handoff
Questions before routing
These answers prepare the request; the reviewed quote controls project-specific commitments.
From what the build must prove. For geometry, clearance and assembly sequence, printing is faster and cheaper — FDM at ±0.2 mm or SLA at ±0.1 mm in days. For anything where the material behaves, machine it: a printed part carries interlayer strength at only 30 to 70% of its in-plane value, SLA resins soften near 50 °C and creep under load, and neither has the isotropic behaviour of stock material. State the question first and the route follows.
Not a complete one, but it needs more than a model. A model says what shape the part is; it does not say which dimensions are critical, what material and condition to use, what finish applies or what is acceptable. A minimal prototype drawing carrying a ±0.125 mm block tolerance, ±0.025 mm on the features under test, the material and grade, and the acceptance basis is usually enough — and it prevents three suppliers making three different reasonable interpretations.
Everything a validation programme needs from the part side routes through the network: dimensional reports on named characteristics at a stated revision, first-article inspection, material certificates against specifications such as ASTM A276 or ASTM B221, heat-treatment and finish records, surface roughness measurement under ASME B46.1, capability data at a target such as a Cpk of 1.33, and lot or serial traceability. Validation itself — deciding what the product must demonstrate and against which standards — stays with the design owner. Name the characteristics and the evidence and scope, format and price come back on the reviewed quote.
By capturing it into the design rather than into an email thread. Suppliers routinely identify things a drawing does not mark — a wall thin enough to deflect under cutting load, a relationship split across two setups and therefore carrying roughly 0.05 mm of extra positional error, an internal corner radius below 1 mm forcing a slow small cutter, a cross-hole burr nothing can reach. Recording those against the model with a revision identifier is often the highest-value output of a first RFQ.
Almost always coating thickness. Powder adds 50 to 100 µm per surface and anodize 5 to 25 µm growing about half outward, which closes clearance holes, binds threads and takes a press fit into interference — on a fit checked bare, any of those is decisive. Either check fit in the finished condition, or state which features are masked and which dimensions apply after coating.
Next step
Send the application context with the controlled part package. MakeNexa routes capable suppliers from a global network covering competitor-class process categories, then returns a prepared quote or focused clarification for your revision.
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