Designing CNC Machine Parts: 8 Tips to keep in mind

CNC machining is a manufacturing process that creates high-quality outputs by guiding machinery to manufacture parts with the help of computer software. You need pieces that suit the strengths and fit the bill to get the most out of CNC machining. The benefit of using CNC machining is its cost-effectiveness and versatility but there are always some limitations. You can create better designs while keeping these limits in mind before you can begin with the manufacturing process. Here are a few tips for optimizing CNC machining designs.

● Avoid pockets and cavities

While starting with the designing process for CNC milling, it necessary to note the diameter and depth of the cavities. In your design, the suggested depth for the cavity is four times its width because end mills have a limit to their cutting capacity. So, by limiting the depth of the cavities can help you get excellent results. In the case of larger design depths, try the variable depth of the cavity to overcome this issue.

● Internal edges should be round

The CNC machining tools will leave rounded inside corners. Now, using a smaller diameter machining tool will reduce the corner radius but this will result in more passes leading to more machining time. Ideally, you should keep the vertical corner radius one-third of the cavity depth when designing the inner edges, and use the same radius in the inner edges. This results in eliminating any tool changes, which adds complications.

● Change the thickness of thin walls

Thin walls are a big no for CNC machining process. CNC machined parts with thin walls can result in distortion which ultimately slows down the process and makes it difficult for the machine accurately. There would be a significant rise in the cost if you will keep on using thin walls in the parts. To reduce the cost of machining, the width for thin walls should be 0.8 mm for metal parts and for plastic parts it should be 1.5 mm.

● Optimize holes

Machinists use drill bits for machine holes. When deciding on the diameters of the holes in the design, regular drill bit sizes should be used which are measured using metric units. The first 2–3 turns will do all the work. If you will try to go deeper, it can increase the risk of tap breakage. The ideal length of the thread should be 1.5x to 3x of the hole’s diameter.

● Include small features into your design

Sure, you can definitely have small features in your design. But you can follow certain guidelines to make them work out the way you want to. The diameter of the hole should be 2.5 millimeters and the majority of machine shops should be able to give machine holes of this diameter without any problem.

● A key factor should be part tolerances

A company should use part tolerances for its parts other than general tolerances. You can decide what tolerance you want to use based on the part’s form and function. Do keep in mind that looking for higher tolerances can increase your costs, as the project will take longer to finish. To keep costs under the tab, you need to apply tolerances to parts where it’s critical to the design.

● Detach complex parts

The logic is simple, designing multiple single parts is less costly than designing a single complex machine part. This is for complex parts with deep pockets that require hours of machining time and there would be additional material costs. Most of the shops will charge a hefty fee for a complicated part. The ideal way is to detach complex parts into simple parts and assemble them.

● Go for engraved text design on parts

If you require to add text on machined parts, then engraved text works well as it requires less material to be removed from the part. Confused about the font? Use a sans-serif font with keeping the size to at least 20 points. Most of the CNC machines have pre-programmed decisions for these fonts.

Conclusion

When designing parts for CNC machining, they should be machined in a few setups as possible. Still having trouble to optimize the design for CNC machining, then MDA can help you to manufacture precision machined parts.