Cnc Machining Org

PTJ SHOP-Global innovation leader in metalworking.


Advanced 5-axis milling technology or 6-sided complete turning / milling technology.

Cnc Machining Paraphrase

CNC machining refers to a process method for machining parts on CNC machine tools. The process specifications of CNC machine tools and traditional machine tools are generally consistent, but significant changes have also occurred. Machining method that uses digital information to control part and tool displacement. It is an effective way to solve the problems of variable part varieties, small batches, complex shapes, high precision, etc. and to achieve high efficiency and automatic machining.

CNC Machine Operation Process

  • 1. Select and determine the parts and content for CNC Machining;
  • 2. Process analysis of CNC machining of part drawings;
  • 3. Process design of numerical control processing;
  • 4. Mathematical processing of part drawings;
  • 5. Writing processing program list;
  • 6. Make the control medium according to the program list;
  • 7. program verification and modification;
  • 8. First trial processing and on-site problem handling;
  • 9. Shaping and archiving of CNC machining process files.

Cnc Machining Process Analysis

1.Dimensions should conform to the characteristics of CNC machining

In CNC programming, the size and position of all points, lines, and areas are based on the programming origin. Therefore, it is best to directly give the coordinate size on the part drawing, or try to quote the size with the same reference.

2.The conditions of geometric elements should be complete and accurate

In programming, the programmer must fully grasp the geometric element parameters that constitute the contour of the part and the relationship between the geometric elements. Because all geometric elements of the part outline are defined during automatic programming, the coordinates of each node must be calculated during manual programming. No matter what is ambiguous or uncertain, programming cannot be performed. However, due to inadequate consideration or neglect during the design process, part designers often have incomplete or unclear parameters, such as whether arcs and lines, arcs and arcs are tangent or intersected or separated. Therefore, when reviewing and analyzing the drawings, you must be careful and contact the designer in time when problems are found.

3.Reliable positioning reference

In NC machining, the machining steps are often concentrated, and it is important to position with the same reference. Therefore, it is often necessary to set some auxiliary benchmarks or add some process bosses to the blank.

4.Uniform geometry type or size

It is best to use a uniform geometry type or size for the shape and inner cavity of the part. This can reduce the number of tool changes. It is also possible to use a control program or a special program to shorten the program length. The shape of the part is as symmetrical as possible, which is convenient for programming with the mirror machining function of the CNC machine tool to save programming time.

Part Clamping Principle

The Basic Principles Of Positioning And Installation

When machining parts on CNC machine tools, the basic principle of positioning and installation is to choose a reasonable positioning reference and clamping scheme. The following points should be noted when selecting:

  • 1. Strive for a unified benchmark for design, process, and programming calculations.
  • 2. Minimize the number of times of clamping, and process all the surfaces to be processed after positioning and clamping as much as possible.
  • 3. Avoid using the manual adjustment processing scheme of the machine to make full use of the effectiveness of CNC machine tools.

The Basic Principles Of Selecting Fixtures

The characteristics of CNC machining put forward two basic requirements for the fixture: one is to ensure that the coordinate direction of the fixture is relatively fixed to the coordinate direction of the machine tool; the other is to coordinate the dimensional relationship between the part and the machine tool coordinate system. In addition, consider the following:

  • 1. When the batch size of parts is not large, the combination fixture, adjustable fixture and other general fixtures should be used as much as possible to shorten the production preparation time and save production costs.
  • 2. Only consider the use of special fixtures in batch production, and strive for simple structure.
  • 3. The loading and unloading of parts should be fast, convenient and reliable, so as to shorten the machine’s pause time.
  • 4. Each part on the fixture should not prevent the machine tool from processing the surface of the part, that is, the fixture should be open, and its positioning and clamping mechanism components must not affect the cutting during processing (such as collision).

Cnc Machining Precision Calculation

The cnc machining precision is a combination of programming precision △ editing, machine tool precision △ machine, positioning precision △ setting, tool setting precision △ knife and other precision.

  • 1. Programming precision △ is composed of approximation precision δ and rounding precision. The approximation precision δ is generated during the process of approximating a non-circular curve with a straight line segment or an arc segment, as shown in Figure 1.43. The rounding precision is an precision caused by rounding the coordinate value to an integer pulse equivalent value during data machining. Pulse equivalent refers to the displacement of the coordinate axis corresponding to each unit pulse. For ordinary precision CNC machine tools, the average pulse equivalent value is 0.01mm; for more precise CNC machine tools, the pulse equivalent value is 0.005mm or 0.001mm.
  • 2. Machine tool precision △ machine is caused by CNC system precision, feed system precision and other reasons.
  • 3. The positioning precision △ must be generated when the workpiece is positioned on the fixture and the fixture is positioned on the machine tool.
  • 4. Tool setting precision The △ tool is generated when the relative position of the tool and the workpiece is determined.

Cnc Machining Technology

Cnc Milling

Cnc Milling

At the PTJ Shop, you will find the most powerful and innovative CNC-turning service available today, exactly the type you need for your production.

Cnc Turning

Cnc Turning

Milling is an indispensable service for industrial production, and our milling centers ensure higher technical standards. Therefore, the services of PTJ Shop increase your productivity.

Multi Axis Machining

Multi Axis Machining

PTJ offers services dedicated to 5-axis high-precision laser machining of turbine blades and aerospace and industrial gas turbine workpieces.

Swiss Type Automatic Lathe

Swiss Type Automatic Lathe

PTJ has swiss type automatic lathe, which can simultaneously complete turning, milling, drilling, boring, tapping, engraving and other composite machining at the same time.