Design and Manufacturing of CNC Milling for Small scale Industries

如何制作数控铣床：机械项目188金宝搏怎么样

Introduction:
在现代CNC系统中，端到端的组件设计使用计算机辅助设计（CAD）和计算机辅助制造（CAM）程序高度自动化。程序生成被解释为提取操作所需的命令的计算机文件
特定机器通过后处理器，然后加载到CNC机器中进行生产。由于任何特定的组件可能需要使用许多不同的工具 - 钻头，锯等，现代机器通常将多个工具与单个“单元格”组合。其他安装，许多不同的机器都与外部控制器和人机或机器人操作器一起使用，使组件从机器移动到机器。在任何一种情况下，生产任何部分所需的一系列步骤是高度自动化的，并产生与原始CAD设计密切匹配的部分。

With the on-going development of technology and economy, new industrial requirements such as high precision, good quality, high production rates and low production costs are increasingly demanded. Most of such requirements, including dimensional accuracy,
conformance to tolerances of finished products and production rate can be met with better machine tools. With the help of CNC technology, machine tools today are not limited to human capabilities but are able to make ultra-precision products down to Nano scales in a much faster manner. The traditional design philosophy of machine tools is multi-functionality and highest precision possible. However, with the dramatic increase of industry varieties and the growing demand of miniature products, these general purpose machine tools are not efficient, either in terms of machine time or cost, in manufacturing products with special sizes and precision requirements

使用小机器产生小型尺寸对象有几个优点。机器尺寸较小，节省空间。操作机器所需的能量也降低。它现在需要更少的材料和组件来制造机器，因此彻底降低了成本。移动部件的重量也下降，以便在操作期间，振动和噪声以及对环境的污染显着降低。由于机器变得更密集，更轻，它变得更加便携。布局制造工厂可以更加灵活。由于可能更快的操作，生产率和制造速度也增加。

Objective:
The idea behind fabrication of low cost CNC Milling Machine is to full fill the demand of CNC machines from small scale to large scale industries with optimized low cost. A major new development in computer technology is the availability of low-cost open source hardware, such as the Arduino microcontroller. An advantage of open source hardware is that a wide variety of ready-to-use software is available for them on the Web; therefore the prototyping and development times are drastically reduced. Moreover, a wide range of low-cost interfaces and accessories such as Arduino shields are also available. However, for the development of low-cost models of CNC machines, such tools may be quite adequate from the viewpoint of machine control. In this project, the development of a prototype 3-axis CNC Milling Machine using Arduino-based control system is presented with the following specification.
• Low cost
•易于操作
•易于界面
• Flexible
• Low power consumption

方法：
This system can be divided in to three modules.
•机械系统
• 电子系统
• Software system

机械系统从电子系统获取必要的控制信号，最终导致电动机的所需致动。电子系统获取命令或来自软件系统的一组命令，并为机械系统生成控件。

Mechanical System
机械系统以这样的方式组装，使得通过使用线性轴承和导杆实现3轴移动。步进电机安装在每个轴上，每个轴是根据电子设备产生的控制信号作用的运动源circuit. Each stepper motor is coupled to the screw rod which carries nut with the help of coupling bush. This screw rod and nut arrangement is responsible for converting the rotational motion of the stepper motor to linear motion. The linear motion of each axis is carried away通过线性轴承和引导杆组件平稳地连接到能够负载载波的每个轴并且允许在每个轴中线性运动。通过控制步进电机的旋转，直接实现每个轴中的受控运动。通过提供所需的控制信号，也可以通过直接控制步进电机的速度来控制每个轴中的运动速度。因此，固定到末端执行器的主轴的刀具路径被控制在每个轴上，以平滑雕刻或切割工件的切割动作。

电子系统
Electronics system comprises of:
• Power supply
•微控制器板
• Stepper motor driver board
电源供应
电源是CNC系统的核心，它将交流电压转换为直流电压，并为相应的设备提供所需的电压。微控制器板在5V电源下运行，而步进电机板在12V下运行。

微控制器板
选择Atmega 328P基于Arduino基于微控制器的微控制器开发板以控制系统的运动。它充当CNC系统的大脑，它从通过USB串行端口连接的计算机接收来自软件系统的命令。
Arduino development board is flashed with the GCODE interpreter code which was written in the C language, which is responsible to generate the control signal for corresponding command signal from the computer system to the stepper motors which directly controls the motion of the tool path. The command from computer or software system is received and converts them to the actual electronic signals to the Stepper Motor Driver Board.

步进电机驱动板
Pololu A4988，选择用于平稳和安静操作的微步驱动，以驱动NEMA 17步进电机。步进电机驱动板从微控制器板接收控制信号到端子脉冲和导体，产生相应的脉冲digital pulse signals for stepper motor to control the rotation of the motor.

Software System
基于CNC的制造的软件刀具链在图1中表示。要加工的部件采用计算机辅助设计（CAD）软件设计，其输出是众多可接受格式中的许多可接受格式之一的绘图.STL格式。然后将该图馈送到计算机辅助制造（CAM）软件，其输出是用于机器的数值控制的机器可读代码。由于G代码的实现是机器依赖的，因此需要测试Arduino的开源G代码解释器的不同选择，从而获得通过步进电机驱动器的机器轴获得正确的运动。我们已经使用GRBL，一个用于Arduino开发板的开源G代码解释器或铣削控制器。