Choosing between 3D printing, CNC machining, and injection molding depends mainly on how mature the design is, the required materials and tolerances, and how many parts are needed. PCBWay, which offers all three processes, describes them as complementary options rather than direct competitors.
A general guide to production volume is:
| Quantity | Often the most competitive process |
|---|---|
| Fewer than 50 parts | 3D printing |
| Around 50 to several hundred parts | CNC machining |
| 1,000 or more parts | Injection molding |
These are broad guidelines. The right choice still depends on the part’s requirements.
3D printing for prototypes and small runs
With no tooling required, 3D printing makes it easier to revise a design without paying for a new mold or machine setup. PCBWay lists prices starting at about US$4.98 and lead times from around two days, though actual costs and turnaround depend on the technology, material, geometry, quantity, finishing, and shipping.
It can also be used for final parts in small batches. One example is the Soa39mini, a compact wireless split keyboard designed by a customer known as gohanda_kbd. The designer considered a CNC-machined aluminum case but was concerned that metal could interfere with Bluetooth, as the microcontroller sits beneath the circuit board. They instead chose resin 3D printing to create a transparent case.
The case was made from UTR-8100 resin and finished with purple dyeing. The designer reported a smooth surface, even color, and no noticeable warping. After printing about five prototypes at home, they said the process from initial concept to a usable case took roughly a month.
PCBWay offers six additive manufacturing technologies: FDM, SLA, DLP, SLS, MJF and SLM. Material options include resins, nylon, PLA, aluminum, and stainless steel. Resin printing is suited to fine detail and smooth surfaces, while powder-bed nylon processes are useful for functional parts and SLM for metal components.
CNC machining for precision and engineering materials
CNC machining is a strong option when parts need tight dimensional accuracy, specific engineering materials, or a machined finish. It can offer a practical balance of flexibility and cost for batches of roughly 50 to several hundred parts.
The starting price is typically higher than for 3D printing because even a single machined part requires setup and programming. PCBWay lists CNC machining prices from about US$24.89.
Injection molding for larger production runs
Injection molding is designed for repeatable, high-volume production of plastic parts. Creating the mold involves a substantial upfront cost, but the process can become cost-effective at around 1,000 parts or more, when that tooling expense is spread across a large batch.
It is usually wise to validate the design with 3D-printed or machined prototypes first. Modifying a mold can be much more expensive than revising a prototype.
A product may use all three processes
Manufacturing decisions can change as a product develops. A team might use 3D printing to check an early design, CNC machining for precise functional parts, and injection molding once demand reaches production scale. Other projects may go directly to one process because of their material, tolerance, or volume requirements.
PCBWay’s platform lets customers upload a CAD file, select a process and material, specify quantity and finish, and receive a preliminary quote. An engineering review checks for manufacturing issues and confirms the final price. For unusual geometries, materials, tolerances, or finishes, engineers may follow up to clarify requirements.
The company also offers PCB fabrication and assembly, sheet metal, and packaging services, allowing hardware teams to source multiple components through one provider. More information is available on PCBWay’s 3D printing and rapid prototyping services.