Sharing Some Operational Skills and Experiences of CNC Machining

Sharing Some Operational Skills and Experiences of CNC Machining

DongGuang, China, 2019-Jul-22 — /EPR Network/ — In CNC Machining processing, many places need to concentrate on manipulation, so as to prevent some unnecessary problems in the process of manipulation, thereby delaying the progress of work and affecting the efficiency of all work. Underneath, let Xiaobian explain some manipulation skills and experience of CNC Turning for everyone! Let’s learn together.

I. Programming Techniques

1. Processing sequence of parts:

Drilling first and then flat end (this is to prevent shrinkage during drilling);

First roughing, then finishing (this is to ensure the accuracy of parts);

The first step is to process the larger part and the smaller part (which ensures that the surface of the size of the smaller part is not scratched and prevents parts from deforming).

2. Choose the correct rotational speed, feed rate and cutting depth according to the hardness of raw materials.

1) Carbon steel raw material selection of high speed, high feed, large depth of cut. For example: 1Gr11, S1600, F0.2 and 2 mm cutting depth were selected.

2) Cemented carbide should be selected with low speed, low feed and small depth of cut. For example: GH4033, select S800, F0.08 and cut depth 0.5mm;

3) Titanium alloy should be selected with low speed, high feed rate and small cutting depth. For example: Ti6, choose S400, F0.2 and 0.3mm cutting depth. Take the processing of a part as an example: the raw material is K414, which is a special hard raw material. Through repeated tests, S360, F0.1 and 0.2 cutting depth are selected to produce qualified parts.

2. Knife-setting Techniques

Tool alignment is divided into tool alignment instrument and direct tool alignment. Most lathes in our factory have no tool alignment instrument. For direct tool alignment, the following knife alignment technique is direct tool alignment.

Firstly, the center of the right end face of the part is chosen as the cutter point and set to zero. When the machine tool returns to the origin, the center of the right end face of the part is the zero point for each cutter to be used. When the cutter touches the right end face and inputs Z0 click measurement, the cutter compensation value of the cutter will automatically record the value of measurement, which means that Z-axis cutter alignment is good, X-cutter alignment is the trial cutter, and the outer circle of the part is turned with the cutter. Less, the measurement is inputted into x 20 by the value of the outer circle of the car (e.g. x is 20 mm). Click on the measurement, and the cutter compensation value will automatically record the measured value. At this time, the x-axis is also good. This tool alignment method, even if the machine is powered off and the call is restarted, will not change the tool alignment value. It can be applied to large quantities of long-term light production of the same parts, during which no need to turn off the lathe from scratch.

3. Debugging Techniques

In order to prevent errors in the procedure and errors in tool setting and collision, we should first simulate the empty travel, and move the total length of the part to the right in the coordinate system of the machine tool 2-3 times as long as the tool, and then start the simulated processing, confirm the correctness of the program and tool setting after the imitation processing is completed, and then confirm the correctness of the program and tool setting after the imitation processing is completed. The first part is processed. After the first part is processed, the first part is self-checked, confirmed and passed. Then the professional check is found. Only after the professional check is confirmed, the debugging is finished.

4. Experience in preventing collision of machine tools

Machine tool collision has a great impact on the accuracy of machine tools. The impact on different types of machine tools is also different. Generally speaking, the impact on machine tools with weak rigidity is greater. So for high precision CNC lathe, the collision must be absolutely prevented. As long as the operator carefully manages the positive anti-collision way, the collision can be prevented and prevented completely.

The main reasons for the collision are as follows: first, the input errors of tool diameter and length; second, the input errors of workpiece size and other related geometric dimensions and the positioning errors of initial position of workpiece; third, the configuration errors of workpiece coordinate system of machine tool, maybe the zero point of machine tool is reset in the process of machining, and the change occurs. The collision of machine tool mostly occurs in the process of rapid movement of machine tool. At this time, the collision hazards are also great and should be absolutely prevented. Therefore, the operator should pay special attention to the machine tool in the initial stage of the implementation of the program and the machine tool in the time of tool replacement. Once the program compilation error, tool diameter and length input error, then it is very easy to collide. At the end of the program, the cutter withdrawal behavior of NC axis is sequential error, then collision may occur.

In order to prevent the collision mentioned above, the operator should fully develop the performance of the five senses when operating the machine tool, and watch whether the machine tool has extraordinary behavior, sparks, noise and extraordinary noise, sensation and burning odor. If the special situation is found, the program should be stopped immediately, and the machine tool can continue to work only after the problem of the machine tool has been solved.

Only by concentrating on accurate manipulation can we prevent the impact of manipulation errors. We trust that people have learned a lot from the beginning and end of this article. Welcome to continue to pay attention to us. We will periodically launch this kind of knowledge of CNC Turning and manipulation for everyone to learn.

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