When milling complex workpieces, the use of CNC end mills should pay attention to the following issues:

When the diameter of the end mill is large, even if the tool holder and the tool holder are very clean, a knife accident may occur. At this time, the tool holder with a flattened gap and the corresponding side locking method should be selected. Another problem that may occur after the end mill is clamped is that the end mill is broken at the port of the tool holder during processing. The reason is generally because the tool holder has been used for a long time, and the port of the tool holder has been worn into a tapered shape. A new tool holder should be replaced.

The end mills used for processing are mostly spring-clamped, and are in a cantilever state when in use. During the milling process, sometimes the end mill may gradually extend from the tool holder, or even fall, causing the workpiece to be scrapped. The reason is generally due to the existence of the inner hole of the tool holder and the outer diameter of the end mill tool holder. Oil film, caused by insufficient clamping force. End mills are usually coated with anti-rust oil when they leave the factory. If water-insoluble cutting oil is used for cutting, a layer of mist oil film will also be attached to the inner hole of the tool holder. When there is oil film on the handle and the tool holder, the tool holder It is difficult to clamp the shank firmly, and the end mill is easy to fall off during processing. Therefore, before the end mill is clamped, the end mill shank and the inner hole of the tool clamp should be cleaned with cleaning fluid, and then dried before clamping.

The CNC drilling and milling machine must be strictly prepared before operation in order to work well. Preparations before work are as follows:

• 1. Before machining parts, strictly check the origin of the machine tool and whether the tool data are normal and perform the simulation operation without cutting trajectory.
• 2. After the debugging of the program is completed, you can only follow the steps with the consent of the instructor.
• 3. Before starting the machine tool, check whether the electrical control system of the machine tool is normal, whether the lubrication system and oil quality are good, and add enough lubricating oil as required, whether the operating handles are correct, and whether the workpiece, fixtures and tools are firmly clamped. Check whether the cooling liquid is sufficient, and then drive the idle to idle for 3 to 5 minutes, check whether the transmission components are normal, and confirm that there is no fault before they can be used normally.
• 4. Before operation Familiar with the general performance, structure, transmission principle and control program of CNC drilling and milling machine, master the function and operation program of each operation button and indicator light. Do not operate and adjust the machine tool until you understand the entire operation process.