How to Calculate the Cost of Custom Machined components?
Nov 08, 2021
The calculation of CNC machined components cost involves various cost factors, including machining, labor, complexity of component, materials, and finishes.
Machine shops consider the following key factors when determining the cost for a project:
Machining
Machine shops use machines such as mills and lathes for part fabrication. 3-axis and 5-axis milling and turning machines provide the flexibility to design component with complex geometries and tight tolerances. Machining costs depend on the type of machine and the number of hours it will run, typically referred to as machine time.
Component Features
A component’s features refer to the geometry and complexity in design. For component with complex features, more programming time, run time, and setup time becomes necessary. Complex component may also demand specialized tools, multiple setups and machines to fabricate, increasing the final product’s cost.
Material
A material’s cost and machinability will be a major factor in determining the cost. Materials include aluminum, stainless steel, plastics, and many others.
Labor
CNC machines require almost no human intervention once set up. A machinist, engineer, or programmer must perform specific steps. Those include:
- Programming: A programmer converts a CAD file into a CAM file for the CNC machine to process. Some AutoCAM technology automatically programs toolpaths, greatly reducing the reliance on humans for this step in manufacturing.
- Setup: A machinist will set up the machine/s for production. Someone always has to cut the billet, set it up in the workholding and load the tools into the tool changer. The cost depends upon the quantity and complexity of component produced.
- Quality control: Quality procedures differ from one shop to the next. Typically a shop will have a quality team and training that varies depending on roles.
- Post-processing: Part-assembly, cleaning, support removal, and surface finishes typically require manual intervention.
Finishes
Surface finishes improve the final surface of a part, removing any tool marks or roughness, fulfilling cosmetic purposes, and providing wear resistance. Machine shops offer a wide range of surface finishes for different materials. Surface finishes affect part tolerances and range from simple “as-machined” to more expensive anodizing or bead blasting. The surface finish depends on a component’s application.
