Design Guidelines: CNC Milling
Our basic guidelines for CNC milling include important design considerations to help improve part manufacturability, enhance cosmetic appearance, and reduce overall production time.
|SIZE (3-axis milling)||10 in. x 7 in.|
|SIZE (5-axis milling)||2.6 in. x 2.9 in. x 3.9 in.|
|DEPTH (3-axis milling)||0.75 in. to 3.75 in.|
|Maximum depth that can be milled is 2 in. from either side of part|
|SIZE (3-axis milling)||254mm x 177.8mm|
|SIZE (5-axis milling)||66mm x 73mm x 99mm|
|DEPTH (3-axis milling)||19.05mm to 95.25mm|
|Maximum depth that can be milled is 50.8mm from either side of part|
|SIZE||0.25 in. x 0.25 in.|
|SIZE||6.35mm x 6.35mm|
Typically, Proto Labs can maintain a machining tolerance of +/- 0.005 in. (0.127mm). Parts may be as thin as 0.020 in. (0.508mm) in regions as long as nominal part thickness is above 0.040 in. (1.016mm).
With 3-axis milling, larger part sizes may be available in ABS, acetal, aluminum 6061 and 7075, and magnesium materials.
- For these materials with depths up to 1.75 in. (44mm), maximum size increases to 10 in. by 14 in. (254mm by 356mm).
- For these materials with depths up to 0.75 in. (19mm), maximum size increases to 22 in. by 14 in. (559mm by 356mm).
- For parts in aluminum 6061, depths up to 1.25 in. (32mm) are possible with a maximum part size of 22 in. by 14 in. (559mm by 356mm).
For additional questions, please contact an applications engineer at firstname.lastname@example.org or 877.479.3680.
5-Axis Milling Capabilities
We use 5-axis indexed milling—in addition 3-axis milling and turning—to machine parts. With 5-axis indexed milling (also referred to as 3+2 milling), two axes are stopped while the tool is engaged with the part. This allows for more complex geometries and non-orthogonal features like off-axis holes.
Better finishes are also possible on non-orthogonal surfaces and because 5-axis milling increases machining efficiencies, more cost-efficient parts can be had.
All machined plastic parts are left as-milled, which typically means they show visible tool marks. Some metal parts, on the other hand, allow more choice. Magnesium, like plastic, is always left as-milled. Soft metals like brass, copper, and aluminum can be lightly bead blasted leaving a fine matte finish. Hard metals like steel and stainless steel can also be deburred with a light bead blast which removes metal slivers and sharp or particularly rough areas.
||As-machined, deburred, or deburred with a light bread blast|
We currently support UNC and UNF threads from #2 up to 0.5 in., and metric threads from M2 to M12. Avoid modeling internal threads on your part design.
Sharp inside corners on a part will be radiused (rounded) as a natural result of the CNC machining process. Resulting radii will be identified before the part is milled.
Recommended text considerations for CNC milling:
- Recessed text should have a minimum stroke width of 0.020 in. (0.508mm).
- The spacing between characters on raised text should be 0.020 in. (0.508mm) or greater.
- If design permits it, opt for raised text versus recessed.
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