Custom Parts RFQ Checklist: What to Include Before Requesting a Quote
A clear request for quotation helps a manufacturing partner understand the part, compare feasible routes and identify missing information. It also makes it easier to compare quotations on the same basis.
Describe the part and its purpose
Provide the current model and drawing, a part number, revision and units. Explain whether the part is for a visual review, assembly trial, functional test or production use. Identify the interfaces and requirements that cannot change.
Define material, finish and quantity
Specify a material grade if it is fixed. If alternatives are acceptable, describe the properties you need rather than asking for an unspecified equivalent. Include finish, color, masking and realistic quantity options. Note whether you expect one order or repeat batches.
State acceptance and delivery needs
List critical dimensions and any requested inspection records or material documentation. Provide the shipping destination and target date, and distinguish a preferred date from a fixed project constraint. Ask whether finishing, inspection, packaging and shipping are included in the proposed scope.
Close the loop before ordering
Review assumptions, exclusions and unresolved questions in the quotation. Confirm that both sides refer to the same revision and quantity. Manufacturing should proceed against an agreed package; a quotation based on an early model should be reviewed after a design change.
Discuss your project
Share your model, drawing revision, quantity and application with Winston Rapid. Material availability, manufacturing feasibility, inspection requirements and delivery are confirmed during quotation.
STEP, STL and PDF: Which Files Should You Send for a Quote?
The most useful quotation package combines a clear shape definition with requirements that a model alone may not communicate. File choice depends on the process and the information available.
Use a solid model where possible
For machined components, a STEP or IGES file can communicate the three-dimensional geometry. Check the units and the intended revision before exporting. If several components are included, identify which bodies are separate manufactured parts and which are only assembly references.
Check mesh files before printing
An STL or 3MF may be appropriate for a printing inquiry. Check that the geometry is complete and that scale is unambiguous. A coarse mesh can make a curved surface look faceted; exporting a new mesh from the original CAD is preferable to hiding that problem with a cosmetic finish.
Add a requirements drawing
Use a PDF to communicate threads, fits, critical dimensions, surface requirements and inspection notes. State which document governs if the drawing and model conflict. A supplier should request clarification rather than silently choosing a conflicting value.
Make the package easy to identify
Name each file with a part number and revision. Include quantity, material, finish and any assembly context in a short accompanying brief. If the design is still changing, say which features are provisional and which must be preserved.
Discuss your project
Share your model, drawing revision, quantity and application with Winston Rapid. Material availability, manufacturing feasibility, inspection requirements and delivery are confirmed during quotation.
CNC Design Review: Internal Corners, Deep Pockets and Thin Walls
A machined feature must be reachable by a cutting tool while the part remains securely held. Reviewing tool access early can reduce unnecessary complexity without changing the part’s purpose.
Allow practical internal corners
A rotating end mill leaves a radius at an internal vertical corner. If a square mating component must fit, review a larger corner radius, a relief or a revised interface. Extremely small radii may require smaller tools and a different machining strategy.
Question deep, narrow features
A deep cavity with limited access can require slender tools and additional operations. Ask whether the full pocket depth is necessary, whether the opening can be enlarged or whether a different construction would preserve the function. The best change depends on the surrounding geometry.
Support the part during cutting
Thin walls and long unsupported features can move during machining. Consider local stiffening or a revised sequence, but do not add material without reviewing the functional requirement. Both material behavior and workholding influence feasibility.
Mark the features you cannot change
Separate flexible geometry from fixed interfaces. Explain why a particular corner, wall or cavity is required and identify the applicable drawing revision. This lets a manufacturing review focus on workable alternatives instead of assuming that every detail is equally negotiable.
Discuss your project
Share your model, drawing revision, quantity and application with Winston Rapid. Material availability, manufacturing feasibility, inspection requirements and delivery are confirmed during quotation.
SLA vs. SLS: Choosing a Process for Your Next Prototype
SLA and SLS can both produce useful prototypes, but they solve different design problems. Choose the process around the intended evaluation rather than the appearance of a material name.
When surface detail is the priority
SLA uses light to cure liquid photopolymer. It is often considered for detailed presentation models and fit checks. Discuss visible surfaces, support locations and post-processing. Resin selection matters: a visually convincing part should not automatically be treated as equivalent to an injection-molded thermoplastic.
When a polymer powder process fits
SLS builds parts from polymer powder. Surrounding powder supports the build, so attached support structures are generally unnecessary. Internal spaces still need a way to remove powder. Review texture, wall geometry, access for cleaning and any mating interfaces.
Compare the complete requirement
State the load, temperature, exposure and duration of the intended test. Ask about the specific material rather than comparing process names alone. Painting, inserts, sanding or secondary operations can change the manufacturing route and the acceptance checks.
Use a small evaluation build
For an uncertain fit or tactile requirement, consider a representative test feature before a larger order. Record orientation, material and finishing with the evaluation. Published design guidance is a starting point; achievable details and delivery need a project-specific review.
Discuss your project
Share your model, drawing revision, quantity and application with Winston Rapid. Material availability, manufacturing feasibility, inspection requirements and delivery are confirmed during quotation.
Further technical reading: Protolabs introduction to SLS. External guidance describes its publisher’s processes, not Winston Rapid specifications.
Sheet Metal Design Review: Bends, Holes and Hardware
Features that look separate in a flat sheet can interact during bending. A design review should consider the final shape, the forming sequence and the space needed for tools.
Look around each bend
Review holes, slots and inserts near bend lines. Forming can distort nearby features, and a flange can limit tool access. If a location is fixed by the assembly, flag it as critical so reliefs or an alternative sequence can be considered.
Keep the material definition consistent
Specify one material grade and thickness for each sheet component. Bend radii and minimum flange dimensions depend on the material, thickness and tooling. Discuss them with the fabricator instead of applying a universal dimension to every project.
Check hardware access
Confirm that hardware can be installed after the necessary bends, and that tools can reach the installation area. Share the hardware specification rather than only a nominal hole size. Test whether a fastener can be inserted and tightened in the finished assembly.
Review the assembled condition
Dimension the interfaces that matter after forming, including gaps between panels and mounting positions. Avoid demanding tight control of every nonfunctional edge. A complete review balances assembly needs, cosmetic expectations and a feasible fabrication route.
Discuss your project
Share your model, drawing revision, quantity and application with Winston Rapid. Material availability, manufacturing feasibility, inspection requirements and delivery are confirmed during quotation.
Further technical reading: Protolabs sheet metal design guidelines. External guidance describes its publisher’s processes, not Winston Rapid specifications.
Preparing a Sheet Metal Enclosure for Quotation
An enclosure quote needs to describe the formed assembly, not just a flat outline. Provide enough information to show how panels, hardware and mating components fit together.
Send the formed model and drawing
Include a 3D model, material grade, sheet thickness and a dimensioned PDF. A DXF can help communicate the flat profile, but the formed geometry and bend directions still need to be clear. Agree who owns the production flat pattern and bend allowances.
Show assembly details
Identify inserts, welds, fasteners and purchased hardware. Supply an assembly view when several panels interact. If doors, covers or connectors must line up, identify those interfaces and the functional clearance required.
Separate cosmetic requirements
Mark outward-facing surfaces and areas that require masking. Include coating color and texture references. Decide whether small gaps, weld marks or hardware impressions are acceptable on visible faces rather than leaving appearance until final inspection.
Include a release checklist
Check that every component has a part number and revision. State the quantity of complete assemblies as well as spare panels or hardware. Add the destination, packing expectations and target date. Fabrication details and delivery commitments should be confirmed after review.
Discuss your project
Share your model, drawing revision, quantity and application with Winston Rapid. Material availability, manufacturing feasibility, inspection requirements and delivery are confirmed during quotation.
Surface Finishing and Part Fit: What to Specify Before Manufacturing
Finishing is part of the manufacturing specification. Treating it as a final cosmetic choice can create avoidable questions about fit, masked areas and acceptance.
Identify visible and functional surfaces
Mark which faces will be seen and which locate, seal or mate with other components. A uniform cosmetic finish and a controlled assembly interface may need different preparation. Indicate surfaces that should remain untreated.
Discuss dimensional impact
Some treatments add material, while others alter the existing surface. The amount and uniformity depend on the process. Ask how the selected finish will be accommodated on tight fits, threads and locating features instead of assuming the finished dimensions equal the machined dimensions.
Specify more than a color
Include the finish process, material substrate, color reference, texture and masking requirements where relevant. If matching an existing part, provide a sample or explain the viewing conditions. A screen image is not a reliable acceptance standard for a precise color match.
Review the complete route
Finishing may involve handling, racking, cleaning and additional inspection. Agree acceptable contact marks and packaging for finished surfaces. Confirm availability and the inspection approach with the quotation; a finish name alone does not define every result.
Discuss your project
Share your model, drawing revision, quantity and application with Winston Rapid. Material availability, manufacturing feasibility, inspection requirements and delivery are confirmed during quotation.
How to Specify Inspection Requirements for Custom Parts
Inspection requirements should explain how a part will be accepted, not simply request that every dimension be checked. A useful brief connects critical features to the part’s assembly and function.
Identify the features that matter
Highlight mating faces, locating holes, sealing surfaces and other functional interfaces. Specify the drawing revision and units. Where a dimension depends on a reference surface or axis, make that relationship clear rather than leaving it to interpretation.
Define the evidence you need
Discuss whether you require a dimensional report, a first-piece review, material documentation or photographs of cosmetic surfaces. State whether records must identify individual parts or a batch. These are different deliverables and should be agreed before the order is released.
Separate measurement from appearance
A dimensional check cannot define every cosmetic expectation. Identify visible faces and acceptable surface conditions. If appearance is important, agree a reference sample or a documented visual review method rather than relying on the word “perfect.”
Plan acceptance before production
Decide how deviations will be communicated and who can approve them. If an assembly test is required, identify the mating components and test conditions. Measurement method, coverage and any special documentation may influence both price and delivery.
Discuss your project
Share your model, drawing revision, quantity and application with Winston Rapid. Material availability, manufacturing feasibility, inspection requirements and delivery are confirmed during quotation.
What Should Your Prototype Prove? Write a Test Plan Before Ordering
A prototype is most useful when it answers a specific question. An attractive model, an assembly sample and a functional test part may need different materials, processes and acceptance criteria.
Start with the decision
Write down the decision you expect to make after evaluating the part. For example: can an operator reach the connector, does the cover assemble without interference, or is the handle comfortable? Choose observable checks rather than a broad request for a production-like sample.
Match the build to the test
For a visual review, prioritize shape and appearance. For an assembly trial, identify interfaces and mating components. For a mechanical test, describe the load, temperature and exposure conditions. A material that looks appropriate may not represent the intended product’s behavior.
Control the comparison
Record the CAD revision, manufacturing process, material and finishing used for each prototype. Use the same test setup when comparing alternatives. Document photographs, measurements and observations so the next design iteration follows evidence.
Keep the limits visible
Passing a prototype check does not establish production consistency, service life or regulatory compliance. Note what was not tested and whether the manufacturing process will change for the next stage. This makes the handoff to a pilot batch clearer.
Discuss your project
Share your model, drawing revision, quantity and application with Winston Rapid. Material availability, manufacturing feasibility, inspection requirements and delivery are confirmed during quotation.
Planning a Low-Volume Production Run: From Pilot Build to Repeat Orders
A successful small batch starts with a clear definition of what must stay consistent. Before requesting production pricing, separate the features that are already validated from those that still need testing.
Define the pilot objective
Decide whether the first batch is intended to validate assembly, finishing, packaging or customer acceptance. Write a short acceptance checklist and identify who will approve the parts. A pilot that tries to resolve every unknown at once can make the results difficult to interpret.
Freeze the production package
Give the model, drawing and specification a matching revision. List the approved material grade, finish, hardware and any purchased components. If a feature changes, describe the change explicitly instead of relying on a new filename alone.
Separate initial and repeat-order costs
Ask which activities are specific to the initial batch, such as fixture preparation or first-piece review. Discuss several realistic quantity options rather than an optimistic annual volume. A lower unit price does not necessarily mean a lower total inventory cost.
Agree the release sequence
Confirm whether first-piece approval is required before the remaining parts are made. Include inspection, finishing and packing in the delivery discussion. Repeat orders should still reference an approved revision and a confirmed schedule.
Discuss your project
Share your model, drawing revision, quantity and application with Winston Rapid. Material availability, manufacturing feasibility, inspection requirements and delivery are confirmed during quotation.
