CNC, 3D printing, sheet metal, injection molding and rapid prototyping serve different needs. Compare material, geometry, critical features and demand to build a shortlist for engineering review.
These are starting points, not automatic recommendations. A part may need several operations.
Consider 3D printing first. Check supports, powder or resin removal and how orientation affects properties and surfaces. Functional testing also requires materials representative of the intended environment.
| Process | How it forms a part | Needs worth evaluating | Cost and scheduling factors |
|---|---|---|---|
| CNC machining | Removes material from stock by cutting | Functional parts, mating surfaces, specified metals or plastics | Workholding, toolpaths, machining time and material utilization |
| Industrial 3D printing | Builds a part layer by layer | Complex geometry, iterative validation and internal structures | Build volume, orientation, supports, finishing and batching |
| Sheet metal fabrication | Cuts sheet, then bends or joins it | Enclosures, brackets, panels and sheet structures | Thickness, nesting, bend count and joining operations |
| Tooling & injection molding | Fills a mold with molten material and cools it | Stable plastic designs with demand that can justify tooling | Tooling, trials, cavity count, cycle time and revisions |
| Rapid prototyping | Combines machining, printing or silicone-mold casting with finishing | Product reviews, appearance and assembly checks, functional samples | Validation scope, masters and molds, finishing and assembly work |
There is no universal quantity crossover or guaranteed tolerance for a process. Feasibility, pricing and lead time depend on drawing review and the confirmed quote.
These are starting points. Drawings, tolerances, materials and quantities determine the final recommendation.
Functional metal and engineering plastic parts with defined requirements for fit, strength and critical dimensions.
Internal corners depend on cutter radius. Deep narrow pockets, thin walls and difficult workholding can add operations or require design changes.
Complex geometries, appearance models and iterative designs for shape and functional validation.
Layer properties, surface texture and accuracy depend on the specific technology. Enclosed cavities need support, powder or resin removal strategies; critical faces may need machining.
Enclosures, brackets and sheet structures made through cutting, bending and assembly.
Check bend radius, springback, hole distance from bends and tooling interference. Thickness is generally constrained by the chosen sheet stock.
Stable plastic part designs where lifecycle demand can justify tooling and scheduled production batches.
Draft, wall transitions, gates, parting lines and undercuts affect tool design. Revisions may require tool modification or replacement.
Build samples for appearance, assembly and functional validation by combining CNC prototypes, 3D printing, silicone-mold casting and finishing around product-development needs.
Rapid prototyping is a development service combining processes, not a single forming method. Casting resins and printed materials may differ from production materials; paint, plating and bonding can affect dimensions. Define display features separately from functional and assembly requirements.
Specify grade, loading, temperature, chemical exposure and appearance. Similarly named printed, molded and machined materials are not necessarily equivalent.
Mark datums, mating surfaces, tolerances and inspection requirements. Avoid applying the tightest tolerance to every dimension.
Compare the current batch and expected lifetime demand. Include fixtures, finishing, inspection and design changes in total cost.
State target dates, finishes, assembly, packaging and split shipments. Production time is not the same as final delivery time.
You can start a conversation with incomplete information. Manufacturing commitments must be confirmed before production.
No. Material, size, geometry, surfaces and fit requirements matter. A simple metal part can suit CNC even in very small quantities. Printed parts may still need machining and finishing.
No, but define the validation goal. Appearance, assembly and performance tests need different levels of material and process similarity. Recheck critical properties and dimensions after switching processes.
Use the same drawing revision, material targets, quantities, acceptance criteria and delivery scope. Include tooling, finishing, inspection, shipping and future changes, not only unit machining cost.
Upload models and necessary 2D drawings with critical requirements. If the process is uncertain, share the application so the options can be reviewed.