How to safely and correctly start a CNC machining program?

　　Why is this content arranged this way?

　　This is also considering that if you are just starting CNC machining or have arrived at a mass production unit or position.

　　The company and other personnel have already set the offsets of the tool, workpiece coordinate system, etc...

　　This program has even been verified and has been used to normally machine many parts.

　　Usually, you only need to load the workpiece according to the specifications, and then press the start button to run the program normally.

　　In this case, we need to understand how to safely and normally start a machining program.

　　I have been engaged in CNC machining for more than ten years, and I have seen many unsafe machining situations.

　　I have also seen the main shaft as thick as a bowl break. You can imagine how shocking the sound is when an impact occurs, and what kind of insecurity it creates;

　　I have also seen the impact during processing, the knife breaking the machine's safety glass and flying out, and the flying tool flying past a colleague's head, a very dangerous situation!

　　Safety is always the top priority in any work we do!

　　Moreover, some CNC equipment is very expensive, costing hundreds of thousands or even millions of yuan.

　　You can imagine how much economic loss will be caused if you cannot correctly and safely run a machining program.

　　We may encounter various unimaginable problems in CNC machining. Even if this program has been proven to have been run and is error-free, it is hard to imagine what other problems may occur.

　　For example, if you take over a shift, you don't know what the previous shift did or what problems occurred.

　　Therefore, if you can correctly start a machining program, you may be able to find problems in advance, reduce waste products, avoid tool collisions, and prevent accidents such as personal injury and property loss...

　　So we must know how to safely and normally start a machining program, not just correctly, what's the difference?

　　Although you can safely and normally start a machining program, it does not necessarily guarantee that the machined parts are genuine; these are different concepts. Safely and normally starting a machining program means this.

　　Before starting to execute a machining program, the premise is that all the preparatory work has been done.

　　The workpiece has been clamped and installed in place, or the blank has been set up with the tool and loaded into the machine's tool magazine.

　　Including the tool length has been measured and entered into the data.

　　The workpiece coordinate system has been measured and set. This may have been set by the previous shift's personnel, or it may have been set by yourself.

　　Of course, if it is set by others, you need to check and confirm again whether the workpiece coordinate system offset value has been set.

　　Select the correct machining program to load. At this time, you can press the start button on the machine tool to start executing a machining program.

　　After the program starts executing

　　You can turn on the single-step mode "Single Block" button. When you press it, the light next to it will turn on, and you will enter the single-step mode. The purpose is also to facilitate debugging, find errors, and correct them in time.

　　This single-step mode executes once with each press, strictly speaking, it executes instruction by instruction.

　　Execute a segment of instructions, press the start button, and then execute the next segment of instructions. For beginners, this is safer.

　　At the same time, turn off the coolant to facilitate viewing the tool position. At the same time, you need to operate some buttons on the control panel to display the program and the tool position of the machine tool on the machine tool screen.

　　You need to find these buttons on the control panel, or you can ask your colleagues. Of course, we may also introduce them later.

　　At the same time, place your hand on the rapid traverse rate or feed rate button to increase or decrease this rate, making it easier to control the tool movement, observe the tool position, and estimate how far the tool needs to move.

　　Each machine tool has its own characteristics. Some machine tools are placed on the rapid traverse rate, while others are placed on the feed rate.

　　Specifically, you need to select the corresponding rate button according to the machine tool you are using.

　　Program Inspection Process

　　During the manual control of the rapid traverse rate or feed rate, observe which instruction the program is executing, observe the position displayed on the screen that has already moved, and observe the "Remain" (Remain indicates the remaining distance) on the screen.

　　For example, we now see that the screen shows that the instruction is to move to Z, the tool's tool position moves to Z0.6924. After executing the instruction, it has moved to the 0.85725 position, and there is still a distance of 0.16485 to go.

　　At this time, let it stop moving, and then observe and estimate whether this is roughly the distance. If the difference is large, there must be a problem with the program; the program should be stopped and the error should be checked. Either your workpiece coordinate system offset is incorrect, or your tool length is incorrect...

　　If the estimation is correct, you can cancel the single-step mode, turn on the coolant, gradually increase the feed rate until you hear a relatively normal cutting sound, and then you can start the normal machining program.

　　Program Normal Execution

　　If the machining program has been verified, or others have run it normally, after safely and normally starting the machining program, you can cancel the single-step mode or the Optional Stop mode and execute the program normally.

　　If the program is still in the verification stage, it is recommended to treat each tool as the beginning of the program.

　　If the program cannot automatically stop before the tool call instruction, you can modify the program.

　　Add a stop instruction such as M00 or M01 before the tool call instruction, and restore normal operation after verification.