CNC lathe arc problem? 5. CNC lathe arc problem?

In the milling process of CNC lathe, according to the relationship between the rotation direction of the milling cutter and the contact part of the workpiece and the direction of cutting feed, it is divided into two types: climb milling and conventional milling. When the direction of rotation of the contact part between the milling cutter and the workpiece in the CNC lathe is the same as the feed direction of the workpiece, the force of the milling cutter on the workpiece is the same as the feed direction of the workpiece, which is called by-milling.

In this case, it may be that the radius of the drill bit used is relatively large, resulting in a part of the area that he walked to not be cut. One possibility is that you have the previous point in a row, and the latter point is collinear, resulting in the machine tool not recognizing this position, so this step is not carried out.

Finishing e.g. Tip Programming without radius compensation G0 Z2 G99 G1 Z0 G03 X16 z-8. g1 x20.Programming with radius compensation knives.

The realization of the arc radius compensation of the CNC lathe tool is G40, G41, G42.

The G40, G41, and G42 commands are modal commands, and G40 is the default value. In order to change the direction of the tip radius compensation, you must first use the G40 command to remove the original left or right tool compensation state.

The G40, G41, and G42 commands cannot appear in the same program segment as the G02, G03, G71, G72, G73, and G76 commands. Tool compensation is not possible when the G01 program section has a chamfer control function.

When the tool is worn, resharpened or replaced with a new tool, and the tip radius changes, only the r value of the tool parameter needs to be changed in the tool offset input interface without modifying the programmed machining program.

Possible causes of the error.

1 The hypothetical tip t is in the wrong position.

The imaginary tip of the tool is shown in the figure below, which represents the tools in different directions, which means that the turning tools are of different shapes.

There is x z in the knife patch, followed by r and tr values, and the values of t need to be entered correctly.

For example, the radius tip of the right-hand outer circle knife has an r-value t-value of 3

The radius of the boring cutter r-value t-value2

2 g41 g42 is used incorrectly.

See the figure below for the outer circle of the car in the negative direction of the z-axis, use g42, and vice versa, use g41

The interior hole is in the negative direction of the z-axis, and G41 is used in reverse, and G42 is used in reverse

Inaccurate tool alignment and incorrect arc value of the tip may lead to changes in the outer circle size.

G41 or g42 got it wrong.

Or the t-direction is wrong.

What is the reason for the loss of roundness of the outer circle of the CNC lathe? Hello dear! First of all, I am skeptical of what you said about "no matter what material", to check whether the machine tool has produced an ellipse, you must use brittle materials, generally gray cast iron, the diameter is not less than 30mm, the clamping part is flat and reliable, the workpiece stretches out about 40 to 50mm, and the tool is sharp, so that the data obtained after turning is more reliable.

If you don't have gray cast iron on hand, you can also replace it with a brass rod of the corresponding size. There are many factors that cause loss of roundness after turning, in addition to the lack of accuracy of the machine tool itself, the process is unreasonable, the tool is not sharp, the chuck is aging, and the workpiece is too thin will produce roundness. Or try to wrap a little thick copper skin in the workpiece clamping part during processing to see if the situation is improved, and then test the accuracy of the machine tool.

Hope it helps! If my answer is helpful to you, please give a thumbs up (in the lower left corner), I look forward to your like, your efforts are very important to me, and your support is also the motivation for my progress. Finally, I wish you good health and a good mood!

Circular interpolation instruction:

G02 Clockwise arc interpolation: Along the tool feed path, the arc segment is clockwise.

G03 Counterclockwise circular interpolation: Along the feed path of the tool, the arc section is counterclockwise.

Circle guess the radius of the Bucha arc programming

Format: G02 G03X Y Z R F;

Move to the start point of the arc;

G02 G03 + Arc End Coordinates + R Arc Radius. (arc "or = semicircle with +r; -r is used for larger than a semicircle (180 degrees) and less than a full circle (360 degrees). Circular radius r programming cannot be used for full circle machining. ）

Advantages and disadvantages of CNC programming:

1. Advantages. It is mainly used for point processing (such as drilling, reaming) or processing of parts with simple geometry (such as plane, square groove) and zero drawbacks, with a small amount of calculation, a limited number of program sections, and intuitive programming that is easy to implement.

2. Disadvantages. For parts with spatial free-form surfaces and complex cavities, the calculation of tool trajectory data is quite cumbersome, laborious, error-prone, difficult to proofread, and some even impossible to complete.

With the round head tool of R5, the rough turning path is arranged in concentric circles, and the processing from right to left is programmed with G02. The processing arc is basically formed by interpolating the two axes of the lathe XZ with the two axes of the lathe, and the instruction is G02 G03. To set the arc diameter is the size specified in the drawing, and then ensure that the two round dots and tangent points are on a straight matching cover line.

Note that to determine whether it is clockwise or counterclockwise, you need to look at the drawing. When judging, look at the coordinates of the starting point and the end point of this arc, whether the line from the starting point to the end point is straight or reverse, if you see that it sells limbs clockwise, use g02, and counterclockwise use g03.

When CNC lathe machining of the outer circle, breaking is one of the very important processing methods. The following introduces two methods of CNC lathe external cutting of the cylinder:

1.Front-cutting breaking: In the early part of the turning, the cutting tool touches only a small part of the surface of the workpiece, and then stops feeding and turns the lathe at an angle.

This is followed by a short cut, then the feed is stopped again and the lathe angle is turned again. This is done sequentially until the desired machining length is reached. This method is suitable for large-diameter workpieces that cause a large impact on the cutting tool.

2.Multi-stage cutting of machining: Splitting the machining length into multiple segments, machining only the current section of the length each time it is turned.

Wait until the turning is complete, the rotary lathe is above again and further turns the next length. This method does not cause a large impact on the cutting tool and is suitable for a wide range of workpiece diameters.

In conclusion, when CNC lathe machining of the outer circle, the method of breaking should consider factors such as the size, material and shape of the workpiece to ensure the best workpiece quality and cutting tool life.