Aluminum Fastener,Aluminum Rivets,Aluminum Screws,Aluminium Rivet Taizhou TS HARDWARE Co., Ltd , https://www.shuwengroup.com
The physical map shown in Figure 1 is an outsourced component produced during the internship training at our hospital. It is a conveying screw shaft, which is part of a machine used for transporting materials. The material is made of cast aluminum alloy. Overall, the component features a tapered thread with a left-hand configuration, and the spiral groove has a complex shape. The length of the spiral section is 550 mm, and due to its poor rigidity during machining, the cutting amount must be kept low. The spiral groove is composed of three arcs and includes straight segments, making it a special-shaped thread that cannot be machined on standard machine tools. Additionally, there is no direct threading code available on the CNC lathe, which makes the main challenge the programming process and tool selection.
**Processing Program Analysis**
The core idea behind CNC machining programming is accurately describing the contour of the part. Therefore, the key focus of this thread programming lies in precisely representing the shape of the spiral groove. Since there's no pre-defined threading code available, we use the G32 command in macro programming to machine the part, as illustrated in Figure 2.
As shown in Figure 2, the coordinates of points along the R4mm arc change throughout the machining process. To calculate these coordinates, we start by defining the initial point A of the thread. From there, we determine the center coordinates of the R4mm arc (which remain constant). Similarly, we can calculate the center coordinates for the R5mm and R25mm arcs. The program calculates the starting angle for the R4mm arc and uses the circle equation to determine the coordinates of any point on the arc. For example, if point A is defined with a starting angle #1, then the X-coordinate can be calculated as #3 = COS[#1] * 4. After converting from the circular coordinate system to the workpiece coordinate system, the formula becomes #3 = COS[#1] * 8 + 94.688, where 94.688 represents the diameter at the center of the R4mm arc. Similarly, the Z-coordinate for point A would be #2 = SIN[#1] * 4, and after conversion, it becomes #2 = SIN[#1] * 4 - 593.575, reflecting the Z-coordinate of the R4mm arc’s center.
This calculation is repeated for the endpoint of the arc, and the G32 command is used to connect the start and end points. This completes the macro programming for the R4mm arc. The full program is detailed below:
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**For more details, please download the attachment or refer to "Metalworking (Cold Processing)", Issue 23, 2013.**