3D Hubs is the category leader in on-demand CNC prototyping. Upload a design to receive an instant quote and a Design for Manufacturing analysis for CNC manufacturing, 3D printing, or injection molding.
CNC machining is an affordable and effective manufacturing process, but the method does have some limitations. Create an intelligent CNC design to significantly reduce the cost of production for any custom part.
1. Avoid sharp vertical edges and corners
The tools used for CNC machining all feature a cylindrical shape. As a result, this rounded geometry is passed onto every hole, channel, and groove cut by the machine.
It is extremely difficult to produce a sharp corner with CNC manufacturing. Even if a small tool is used, there will still be a noticeable internal radius.
To reduce the cost of a CNC design, make the radius of each corner as wide as possible; larger tools can remove material much more efficiently. If a right angle is necessary for the final product, design an undercut at each corner that can be accessed by the cylindrical tool.
2. Choose the best material for the design
Materials with high structural integrity are more difficult to machine and are therefore more expensive. Select the cheapest possible material for any design; 3D Hubs offers a variety of materials suited for different applications.
Aluminum is a pliable metal and provides the cheapest CNC machining results. Plastics, steel alloys, polycarbonates, and brass all come with scaling costs according to the material's structural integrity. Stainless steel is by far the most expensive machining material, but it also provides the greatest strength and durability.
Upload a design to the 3D Hubs online manufacturing tool to compare material costs. Generate an instant CNC quote for different materials, preferences, and production methods.
3. Minimize additional machine orientations
CNC mills have multiple directional axes, but some designs still require manual re-orientation. If a worker must personally remove and rotate the object to complete production, the manufacturing costs will naturally increase.
Create designs that can be machined with only one or two orientations. Alternatively, plan to use a 3- or even 5-axis machine; this will increase production costs, but it may not cost as much as manual re-orientation.
4. Break designs into multiple parts
CNC machining is a subtractive manufacturing process. The more material that needs to be removed, the more expensive the final product will be. Projects with thin walls, deep pockets, and complicated geometries have naturally increased manufacturing costs.
Instead of attempting to carve the entire object out of a single block of material, try creating a design with several easy-to-machine pieces. As an example, a container with a deep internal pocket might be better designed as two interlocking parts. This lets the container's walls meet design specifications without paying to remove the entire volume of the internal pocket.
Other features that tend to increase the cost of CNC manufacturing include beveled edges, embossed text, extremely thin walls, and undercuts with non-standard dimensions. Understand the limits of CNC machining early in the design process. In the case of geometrically complex designs, 3D printing might be a more viable manufacturing technology.
3D Hubs offers on-demand 3D printing, injection molding, and CNC online machining services with short lead times and exceptional results. Generate a CNC quote with the 3D Hubs online manufacturing tool and start production on any custom part today.
