Holes designing are crucial for the connection of drilling parts, and it can directly affect the manufacturing difficulty and cost. To realize on-budget and time-efficient CNC manufacturing, here 5 design guidelines about holes for your CNC drilling parts.
1. The intersection of hole and cavity
If the intersection is unavoidable, the center of the hole should be outside the cavity.
2. Small and deep holes
The over-deep hole may break the drill tool, and it's also difficult to remove the chips. The ratio of hole depth to diameter should not be greater than 3. To make room for the chips generating during process, the deep hole requires additional 25% hole depth. Using stepped holes instead of deep holes is recommended.
3. Holes location
Making sure that 75% of hole is inside the part edge. Otherwise, it will easily cause a breakage on drilling tool.
4. The curving holes
It is unfeasible to manufacture a curving hole. The curving holes could be optimized to a combination of three right-angle holes.
5. The axis of holes
The axis of the hole should be perpendicular to the end faces of the inlet and outlet. Otherwise, the drilling tool is prone to skew or bend, or even break. Avoid drilling on curved or inclined walls to improve productivity and ensure accuracy.