When Should We Select Vacuum Casting Not CNC Machining

Vacuum casting and CNC machining are both manufacturing processes used to create parts or prototypes, but they have different strengths and are suited for different applications. Here's when you might consider selecting vacuum casting over CNC machining:

1. Low-volume production: Vacuum casting is well-suited for producing small to medium volumes of parts. It involves creating a silicone mold from a master pattern and then using the mold to cast multiple replicas. If you need a limited quantity of parts, vacuum casting can be a cost-effective option compared to CNC machining, which is typically more suitable for high-volume production.

2. Complex geometries: Vacuum casting is particularly advantageous when dealing with intricate or complex part geometries. The flexible silicone molds used in the process can capture fine details and intricate features that may be challenging or time-consuming to machine using CNC methods. If your part has undercuts, thin walls, or complex internal cavities, vacuum casting can be a better choice.

3. Wide material selection: Vacuum casting offers a broader range of material options compared to CNC machining. With vacuum casting, you can use a variety of materials, including various types of polyurethane resins, rubber-like materials, and even some rigid plastics. CNC machining, on the other hand, is limited to the materials that can be effectively machined, such as metals, plastics, and certain composites.

4. Cost considerations: Vacuum casting can be a more cost-effective option for producing parts with complex geometries or small volumes. The initial investment in creating the silicone mold may be higher than CNC machining setup costs, but once the mold is made, subsequent part production becomes relatively affordable. CNC machining, on the other hand, may be more cost-effective for simple parts or larger production runs due to its higher initial setup costs but lower per-unit costs.

In summary, vacuum casting is often preferred over CNC machining when producing parts with complex geometries, small to medium volumes, or when a wider range of material options is required. However, if you need high volumes of simple parts or require the use of specific materials that are not compatible with vacuum casting, CNC machining may be the better choice. It's essential to consider factors like part complexity, volume requirements, material selection, and cost considerations when deciding between these two manufacturing processes.