How to program CNC screw milling, how to program thread milling

The formation of the spiral line is the synchronous axial movement of the cutter while making circular interpolation motion, and its command format is:

G17x Y Z K F where: G02 and G03 are the rotation directions of the spiral, and their definitions are the same as circular arcs; x, y, z are the end coordinates of the spiral; i and j are the coordinates of the center of the arc on the x-y axis on the x-y plane relative to the starting point of the spiral; r is the projection radius of the spiral in the x-y plane; k is the lead of the helix. The meanings of the following two equations are similar, as shown in Figure C.

g18x___y___z___j___f___g19x___y___z___i___f___

g17 g03 x0. y0. z50. i15. j0. k50. f100

or g17 g03 x0 y0. z50. r15. f100

This should be the same as a machining center! Computer programming is fine!

Thread cutting cycle G92.

Command format: G92 x(u) z(w) f j k l (metric straight thread cutting cycles).

g92 x（u）_ z（w）_ i_ j_ k_ l；(Inch straight thread cutting cycle).

G92 x(u) z(w) r f j k l (metric taper thread cutting cycle).

G92 x(u) z(w) r i j k l (inch taper thread cutting cycle).

Thread Programming Example:

N1G92X50Z120 (Sets up the coordinate system and defines the position of the tool setting point).

N2M03S300 (spindle rotates at 300r min).

To the starting point of the thread, the speed section, the praise of eating the knife deep.

Cutting the thread to the end of the thread cutting, the speed reduction section is 1mm).

N5G00X40 (X-axis direction rewind).

The axis direction retracts to the start of the thread).

Fast forward to the beginning of the thread in the direction of the shaft, and eat the knife deep.

Cutting the thread to the end of the thread cut).

N9G00X40 (X-axis direction rewind).

The axis direction retracts to the start of the thread).

Fast forward to the beginning of the thread in the direction of the shaft, and eat the knife deep.

Cutting the thread to the end of the thread cut).

N13G00X40 (X-axis direction rewind).

The axis direction retracts to the start of the thread).

Fast forward to the beginning of the thread in the direction of the shaft, and eat the knife deep.

Cutting the thread to the end of the thread cut).

N17G00X40 (X-axis direction rewind).

N18x50Z120 (back to tool center).

N19M05 (spindle stop).

N20m30 (the main Cheng Ye faction section sequence ends and resets).

Due to the different CNC systems configured on the CNC milling machine, there are certain differences in the definition and function of the instructions used, but their basic functions and programming methods are still the same. Next, I will tell you about the programming knowledge of CNC milling machine, I hope it will be helpful to you!

Point control function

CNC milling machine'Point control is mainly used for the drilling of workpieces, such as center drilling positioning, drilling, reaming, countersinking, reaming and boring and other various hole making operations.

Continuous control function

The planes and surfaces of the workpiece are milled by linear interpolation, circular interpolation or complex curve interpolation movements of CNC milling machines.

Tool radius compensation function

If you program directly according to the workpiece contour, when machining the workpiece inner contour, the actual contour will be increased by one tool radius value; When machining the outer contour of the workpiece, the actual contour line is one more tool radius value smaller. Using the method of tool radius compensation, the CNC system automatically calculates the tool center trajectory, so that the tool center deviates from the workpiece contour by one tool radius value, so as to process the contour that meets the requirements of the drawing.

Using the function of tool radius compensation, the amount of tool radius compensation can be changed, and the amount of tool wear and machining error can also be compensated, so as to realize the roughing and finishing of the workpiece.

Tool length compensation function

Changing the compensation amount of the tool length can compensate the length deviation value after the tool change, and can also change the plane position of the cutting process to control the axial positioning accuracy of the tool.

Fixed cycle machining function

The application of fixed-cycle machining instructions simplifies the machining program and reduces the programming effort.

Subroutine functions

If the workpiece is machined with the same or similar shape, it is written as a subroutine and called by the main program, so as to simplify the program structure. The function of the reference subprogram makes the processing program modular, and it is divided into several modules according to the process of the processing process, which is written into a subprogram respectively, and is called by the main program to complete the processing of the workpiece. This modular program facilitates machining and debugging and optimizes the machining process.

Flat machining

The milling plane of CNC machine tools can be divided into horizontal plane (xy) processing of the workpiece, positive plane (xz) processing of the workpiece and side plane (yz) processing of the workpiece. Such a flat milling process can be completed by using a two-axis semi-controlled CNC milling machine.

Surface machining

Fixtures

The general fixtures of CNC milling machines mainly include flat pliers, magnetic chucks and platen devices. If pneumatic and hydraulic fixtures are used, the automatic assembly of the workpiece can be realized through the program control fixture, which can further improve the work efficiency and reduce the labor intensity.

Knives

Commonly used milling cutters include end mills, face mills, profile mills, and holemaking cutters.