CNC Milling Parts

Overview

The question “What is the CNC milling process and CNC milling parts?” is often asked. For starters, it’s good to know that CNC stands for “Computer Numerical Control.” Briefly, this means that your milling operations are performed by a computer instead of being done manually.

In CNC milling, the operations to be performed are written in advance in a program. The CNC milling machine reads these operations from the program and performs them without the intervention of a hobbyist, production worker, or craftsman.

What is CNC milling?

CNC milling is a manufacturing process that uses a cutting tool mounted on a rotating spindle to remove material from a block of the raw substrate selectively. The workpiece is rigidly mounted to a table, and this table moves or rotates on different planes so the tool can work at many angles. Sophisticated CNC milling machines can have 5 or more axes of independent motion to make more complex shapes or avoid moving the workpiece to a separate machine.

What are the Axes of Motion on a Typical CNC Milling Machine?

The axis of motion for a CNC milling machine is based on an X-Y-Z coordinate measuring system. All machinists refer to this when describing the basic movements of the mill, relative to an operator facing the machine. A standard CNC mill for example has three axes. The milling spindle represents the Z-axis, moving up and down. The X-axis is left-to-right, and the Y-axis is front-to-back.

When to do CNC milling?

In general, CNC milling becomes more attractive when operations to be performed become more complex or if you want to repeat operations more often. This is because a CNC milling operation requires a program to be written first. If you want to mill a few simple wood joints or a small profile, it often does not pay to write a program for a CNC milling machine.

Nevertheless, CNC milling does have several important advantages, even when only simple machining operations are performed:

• Operations are performed exactly according to instructions. Of course, the milling machine must be properly adjusted, but the computer will take over the instructions one-to-one.
• Operations are reproducible without extra work. You only need to re-enter the same program into the machine.
• Complex operations are performed easily and accurately. Very complex shapes are difficult to mill by hand, but with computer-controlled milling this is not a problem.

CNC machining for the fastest and best results

With a CNC milling machine, you can have complex operations applied to different materials. Not surprisingly, a CNC can be equipped with multiple milling cutters. To increase the versatility of a CNC machine, a CNC machining center with a changeover magazine is often used. A machining center consists of one or more CNC machines that can automatically change cutters and other tools. The advantage of this is that you can have complex operations performed automatically, without having to change cutters yourself.

What are the common CNC milling parts?

CNC milling parts of aluminum

Aluminum can be milled into all kinds of shapes and is therefore ideal for applications where it must be light but above all robust. We can also mill and engrave small signs for lockers or seat numbers, for example. We often paint engravings for an even more beautiful end result.

Aluminum sandwich panels (such as Dibond) are also perfect for milling with a CNC machine. With various milling techniques, the most beautiful creations can be made.

CNC milling parts of Stainless steel

stainless steel has become one of the materials often selected by engineers due to its corrosion resistance and wear resistance. Stainless steel is one of the hardest metals in machining, so CNC milling or turning stainless steel is difficult which makes its cost high and hard to ensure the quality. At FRIMA, we hold the key to successful stainless steel machined parts. Common types of stainless steel that we work with are austenitic, martensitic, 304, 303, 316, 420, duplex stainless steel, etc.

Different kinds of CNC milling stainless steel due to the different mechanical properties and chemical composition of the difficulty of stainless steel CNC milling is not the same. FRIMA has 3-axis, 4-axis, and 5-axis CNC milling Machines.

CNC Milling parts of Plastic

Plastic is increasingly used to replace other materials, such as steel or wood. A major advantage of plastic is that it is wear-resistant. Plastic does not have the property of rotting or wearing out.

With the use of the right technique, it is possible to mill or laser very precise products from plastic sheets (or blocks). Acrylic, for example, is a widely used material for facade letters or displays. But polycarbonate can also be processed, which is more impact-resistant than acrylic.

What is FRIMA’s capability for the CNC milling parts service?

• Maximum Dimensions. The maximum depth that can be milled is 2 in. (50.8mm) from either side of the part. For specific milling dimensions by material, see maximum part extents for machining.

*Hard metals: Titanium (6Al-4V), Stainless Steels (303, 304, 316, 17-4PH), Alloy Steel (4140), Carbon Steel (1018)

**Denotes two-sided machining only

• Minimum Dimensions

• Threading. 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.
• Tolerances. Typically, FRIMA can hold a machining tolerance of +/- 0.005 in. (0.13mm). Part features are recommended to be thicker than 0.020 in. (0.51mm) in all regions and a nominal part thickness above 0.040 in.
• Radii. Sharp inside corners on a part will be radiused (rounded) as a natural result of the CNC machining process. The resulting radii will be identified on your quote.