（1）NC Numerical Control 数字控制 （2）CNC Computer Numerical Control 计算机数字控制
（3）A TC Automatic Tool Changer 自动换刀系统 （4）HSS High Speed Steel 高速钢
（5）MCU Micro Controller Unit 单片机 （6）MDI Manual Date Input 手动手工数据输入
（7）Cad Computer Aided Designing 计算机辅助设计 （8）FMS Flexible Manufacturing System柔性制造系统
cnc 的全称 立式加工中心 卧式加工中心
主轴 立柱 工作台 床身 防溅板 床鞍 操作面板 主轴箱 刀架 控制器 车床 铣床 钻床 刀库 机械手 旧刀具 新刀具 车刀 铣刀 铰刀 钻头 镗刀 丝锥 自动换刀装置 刀具系统 通用刀具 重复定位精度 强度 硬度 刚度 脆度
笛卡尔直角坐标系 第一象限 第二象限 第三象限 第四象限
原点 交点 极坐标 绝对方式编程 增量方式编程 命令
参考平面 参考点 三维空间 正 负 直角三角形 斜边 直角边 对顶角 同位角 数学原理 切线 垂线
三角定理 对边 临边 三角法正弦定理 余弦定理 三角函数补偿 刀具长度补偿 刀具半径补偿 面铣刀 立铣刀 钻头 过切 偏置 试加工 显示屏 实体模型 表面模型
磨耗补偿 几何补偿 主轴驱动 导轨驱动 重复定位精度
驱动 直流电 交流电 传动带 齿轮
步进电动机 非步进电动机 大功率直线电动机
分级驱动 导轨 液压的 脉冲 伺服系统 稳定性
丝杠 反馈单元 作业准备 偏置 拆卸 生产维护 维持生产 工件装卸 托盘交换系统 轮班 麻花钻 精加工刀具 粗加工刀具 型腔铣削 铣螺纹 铣平面 背镗 镗孔 六种操作模式：手动 MDI 自动 手轮 回零 编辑 键盘 处理机 模式切换开关 显示器 空运行 程序检查 空切循环 首件试切削
语法错误 动作错误 作业准备错误大意错误
CAD CAM CNC CAPP FMS CIM
HSS ATC MDI 刀具路径 后处理 型腔 三维线框模型 三维表面模型 三维实体模型 垂直的, 直立的, 水平的车床主轴箱 ; 立柱主轴刀库模态的绝对的增量的; 坐标象限, 四分仪垂直的, 直立的地平线的, 水平的床;headstock 主轴箱; colum 立柱;spindle 主轴;Magazine 刀库;Modal 模态的;absolute 绝对的 ;incremental 增量的;Coordinate 坐标;quadrant 象限, 四分仪;Rigidity 刚性，刚度;Turning 车削;Alloy 合金代码 编码补偿 赔偿伺服系统;Toolpath 刀具轨迹;Boring 镗孔; Stability 稳定性;
3. 指令, 说明书, 教育, 指导 instruction ; 手轮, 驾驶盘 hand wheel ;
机械装置 机构 机制 Mechanism ;转塔式换刀装置 T urret head ;矩阵 Matrix ;
锥度 Taper ; 多种用途的 多目标的 Multipurpose ; 重复定位精度 Repeatability; 公差 Tolerance ; 装配 Assembly ; 交点 intersection ;原点 origin; 命令 command; 矩形的，成直角的 Rectangular; 非模态的 Nonmodal; 二中择一 Alternative; 技术 T echnique; 使最优化 Optimize; 软钢 低碳钢 Mild steel ;激活 Activation;
传动带 Belt; 导轨 Slide;
4、立式加工中心; 卧式加工中心;
铣床; 刀具系统; 笛卡儿坐标系; 程序字符; 程序字; 准备功能; 硬质合金刀具; 铸铁 锻铁; 工件夹紧设备;
刀具长度补偿; 语法错误; 面铣刀; 铣螺纹; Face milling 铣平面;
5、三维空间Three dimentional gird 直角三角形Right triangle 斜角三角形Oblique triangle 程序段Program block 线性插补Linear interpolation 表面粗糙度 表面处理Surface finish 整体硬质合金刀具Solid carbide tool 设置盘setting dial 刀具半径补偿cutter radius compensation 步进电动机S tepping motors 非步进电动机Nonstepping motors 麻花钻Twist drill 型腔铣削Pocket milling 过切over cut 直流电Direct current
交流电Alternating current 空运行Dry run 锁定机床的空运行Machine lock dry run
6、Translate the following sentences into Chinese.
● The chain may be located on the side or the top of the CNC machine .these positions enable tools to
be stored away from the spindle and work. This will ensure a minimum of chip interference with the storage mechanism and a maximum of tool protection.
链式矩阵刀库可以安装在CNC 机床的侧面或顶部，这种位置可使存放的刀具远离主轴和共建，从而最大限度的减少切削对存刀装置的影响，同时更好的保护刀具。
● Ensure repeatability of a tool :center the tool in the spindle such that the tool’s relation to the work
is repeated every time the tool in used.
保证刀具的重复定位精度：将刀心定位于主轴中心，从而保证每次使用该刀具时其相对于工件位置是可重复的。
●
●
● the location of a CNC tool at any time is controlled by a system of XYZ coordinates called cartesian coordinates . 任何时候，CNC 刀具的位置都是由一个叫笛卡尔坐标的XYZ 坐标控制的。 In the early days of NC (before computer numerical control), the NC programmer actually had to
know how many rotations of an axis drive motor equated to an inch of linear movement.
在NC 发展的最初期（计算机数字控制出现之前），NC 程序员确实必须知道走一英寸直线长时各轴的驱动电动机转多少转。
● Many problems in CNC programming involve finding the Xand Y coordinates of tool motion based
on a given length and angle .these tasks can usually be accompolished by using basic right-triangle trigonometry.
在CNC 编程中常碰到根据已知长度和角度确定刀具运动的X Y 坐标问题，这些问题一般是通过基本的直角三角运算解决的。
● A progam format is a system of arranging information so that it is suitable for input to a CNC
controller 。
所谓程序格式就是一套组织信息的系统，其目的是使这些信息更适合输入到CNC 控制器。
● A program is a sequence of bolcks that describe in detail the motions a CNC machine is to execute in
order to manufacture a part .
程序是一组按顺序排列的程序段，它详细描述了为加工某个工件CNC 机床要执行的所有运动。 ● For this reason ,there are those in the industry who feel that manual programming is a thing of the
past .they contend that there are alternative to manual programming that eliminate the need to learn it .
基于这个原因，行业中有些人认为手工编程已经成为过去。他们认为既然有替代手工编程的方法，所以完全没有必要学习它。
● Though this is the case,the beginning programmer must grasp a basic understanding of manual
programming in order to continue on to the alternatives
即便在这种情况下，为了继续学习各种替代方法，初学者夜必须对于手工编程又基本的理解。
● This newwe form of CNC control allows the operator to input programs right at the machinein a
more understandable and graphic manner than with manual programming .
在这种新型的CNC 控制器上，操作员就可以直接在机床上输入程序，这种方式要比手工编程法更容易理解，图示性更强。
● It is difficult to determine precise date for any metal-cutting operation without knowledge of the
practicalities involved.
没有经过实践的知识，要确定任何金属切削加工的准确数据是很难的。
● For example, the condition of the machine, the power available, the rigidity of tooling and
working-holding arrangements, the volume of metal to be removed, the surface finish required, and the type of coolant be used are all factors that have to be considered when determining the appropriate speeds and feeds to be used.
例如，机床的条件、电力状况、刀具刚度及夹具情况、金属切削体积、表面粗糙度要求以及所用冷却液的类型等，都是确定适当的速度和进给时 要考虑的因素。
● Any complex project can be simplified by breaking it down into small pieces, this can make
seemingly insurmountable tasks much easier to handle
通过化整为零，任何复杂的项目都可以得到简化，这可以使表面看来不可逾越的任务变得简单起来。 ● The less a programmer leaves to the setup person’s imagination ,the less the chance there will be of a
mistake being made during the setup .
程序员留给作业准备人员的想象空间越小，作业准备过程中出现错误的机会就越小。
● A better approach is to creat a separate program called a subprogram ,which contains the
instruction for maching one pattern .a main program is also created calls the subprogram as many times as the machining sequence is repeated.
更好的方法是创建一个称为子程序的独立程序，该子程序包含加工某一形状的指令。同时编制一个主程序，需要加工该形状多少次，主程序就调用子程序多少次。
● Just as tool length compensation lets you gorget about each tool’s length as you write the program,so
does cutter radius compensation let you forget about the diameter of the tool as you write the program.
有了刀具长度补偿，编程的时候就不需要考虑刀具长度，于此相同，有了刀具半径补偿，编程的时候就不必考虑刀具直径。
● By varying the voltage input ,their speeds are infinitely variable as they rotate and so a constant
cutting speed can be maintained.
通过改变输出电压其速度可无极改变，这样就可以保持恒定的切削速度。
●
● The ability of the machine to produce continually accurate slide movement is called repeatability. 重复定位精度是机床的一个性能，它能使机床滑动部分连续地, 精确地运动。 A precise definition of repeatability is as follows : The maximum difference that can occur between
the shortest and the
Longest positions achieved in a number of attempted moves to any programmed target position.
重复定位精度的精确定义是：对于程序指定的任意目标位置，（机床）多次运动到此处后，其所到达的最远与最近位置之差的最大值即为其重复定位精度。
● One very good definition of setup-related task is ‘anything that happens from the running of the last
workpiece in the previous production run to efficiently running the first good workpiece in the next production run .
与作业准备相关工作由一个非常恰当的定义，即从前一个加工过程中最后一个工件的加工开始，到开始有效的加工下一个加工过程中第一个合格的工件为止，这期间发生的所有事情都属于作业准备的范
畴
● On the other hand ,many machining centers are equipped with pallet changer s,which allow the
operator to be unloading and loading one pallet while the machine is running another.
另一方面，许多加工中心都配有托盘交换装置，这样操作者就可以在机床加工一个零件的过程中完成另一个零件的装卸。
● The physical positions of the mode switch that are included as manual modes include manual or
jog ,handwheel and zero return.
模式切换开关的多个物理位置都被归为手动模式，其中包括手动、手轮和回零。
● Once the geometry is completed,then we can use a computer-aided manufacturing system to
generate an NC toolpath based on the CAD geometry.
几何形状一旦形成，我们就可以利用计算机辅助制造系统，根据CAD 的几何形状生成数控机床的刀具轨迹。
● The free flowing dry allowed you to take total control of all motion rates with the dry run motion
rate switch .this means when dry is turned on ,you will not be able to tell the difference between rapid motions and cutting motions.
在带进给运动的空运行中，通过空运行速率开关可以控制所有运动的速度，也就是说，只要一打开空运行开关，就看不出快速运动和切削运动的区别。
7、
● Translate the following sentences into english 乍一看，卧式加工中心的结构好像非常不同
at first glance ,it may appear that the c configuration of a horizontal maching center is dramatically different from that of a vertical maching center.
●
● 记住，任何运动都既可以绝对模式又可以增量模式编程 Keep in mind that any motion canbe commanded in either the absolute or incremental mode. 今天，由于矩形坐标系的出现，程序员不必为了对定位运动进行编程而去关心各轴的内部工作了。
Today, thanks to the rectangular coordinate system, programmers need not to concern themselves with the inner workings of each axis in order to command positioning movements.
●
● 进给率是指刀具切入共建材料的速度。The feed rate is the speed at which the cutter penetrates into the work material . 实际上，有了长度补偿，程序员在编程时就不需要考虑刀具的长度问题了。
in essence ，tool length compensation eliminates the need for a programmer to be concerned with a tool ‘s length as the program is written .
MDI 用来输入并执行CNC 命令，一次一条。CNC 命令一经执行就会丢失。
MDI is used to enter and execute CNC commands ,one at a time .Once the CNC command has been executed ,it is lost .
8、Translate the following passage into Chinese or English.
● Although high-speed steel (HSS) is used for small-diameter drills, taps, end mills, and spot drills,
the bulk of tooling for computer numerical control machine involves the use of cemented carbide. 尽管高速钢被用于小直径钻头、丝锥、绞刀、立铣刀以及点钻，但数控机床上大量使用的刀具都是超硬合金材料的。
● Unfortunately, CNC using companies vary dramatically with regard to what they expect their
operators to do. In some companies, the CNC operator does everything, including processing, tool design and fabrication, programming, setup, program loading, program verification, and actually
running production.
不幸的是，CNC 公司对于他们需要操作者做的事情有显著不同， 在一些公司里，CNC 操作者做每件事情，包括工艺、刀具设计、编程、安装、程序加载、程序检查以及实际运行生产。
● tool length compensation will be used for every tool in every program you write, so it mandatory
that you master this form of compensation. Cutter radius compensation is only applicable to milling cutters, and only when milling on the periphery of the tool.As stated several times to this point, cutter radius compensation allows you to work form the work surface as opposed to the cutter ’s center line, meaning you can save yourself a great deal of work if you understand cutter radius compensation. Note that the first two kinds of compensation apply to the cutting tools. Fixture offsets relate to your work holding setup.
刀具长度补偿将要被使用在你编写的每个程序的每把刀具，所以你必须要掌握这种补偿的类型。刀具半径补偿仅仅应用于铣刀，而且仅仅用在铣刀的外围。对于这一点就像陈述好多次那样，刀具半径补偿允许你将工件表面与刀具中线对应，也就是说，如果理解了刀具半径补偿，就可以节约大量的工作时间。
9、ask and answer
（1）、N0020 G18 G91 G00 X3.25 Y-8.75 F30 S500 ;
● ● ● how many program characters in this program block? how many program words in this block?
how many addresses in this block?
（2）、State the main elements of a vertical machining center.
Headstock 、spindle 、Colum 、splash guard 、table 、saddle 、bed 、automatic tools changer
（3）、State three modes of operation
G00 G01 G90 M99 T01
（4）、why learn manual programming? Page 42
（5）、which steps is included as the preparation for programming? Page 53
（6）why is the cutter radius compensation necessary?
（7） please write out six kinds modes of operation.
(8) what is subprogram? Do you think they are necessary ? why ?
（1）NC Numerical Control 数字控制 （2）CNC Computer Numerical Control 计算机数字控制
（3）A TC Automatic Tool Changer 自动换刀系统 （4）HSS High Speed Steel 高速钢
（5）MCU Micro Controller Unit 单片机 （6）MDI Manual Date Input 手动手工数据输入
（7）Cad Computer Aided Designing 计算机辅助设计 （8）FMS Flexible Manufacturing System柔性制造系统
cnc 的全称 立式加工中心 卧式加工中心
主轴 立柱 工作台 床身 防溅板 床鞍 操作面板 主轴箱 刀架 控制器 车床 铣床 钻床 刀库 机械手 旧刀具 新刀具 车刀 铣刀 铰刀 钻头 镗刀 丝锥 自动换刀装置 刀具系统 通用刀具 重复定位精度 强度 硬度 刚度 脆度
笛卡尔直角坐标系 第一象限 第二象限 第三象限 第四象限
原点 交点 极坐标 绝对方式编程 增量方式编程 命令
参考平面 参考点 三维空间 正 负 直角三角形 斜边 直角边 对顶角 同位角 数学原理 切线 垂线
三角定理 对边 临边 三角法正弦定理 余弦定理 三角函数补偿 刀具长度补偿 刀具半径补偿 面铣刀 立铣刀 钻头 过切 偏置 试加工 显示屏 实体模型 表面模型
磨耗补偿 几何补偿 主轴驱动 导轨驱动 重复定位精度
驱动 直流电 交流电 传动带 齿轮
步进电动机 非步进电动机 大功率直线电动机
分级驱动 导轨 液压的 脉冲 伺服系统 稳定性
丝杠 反馈单元 作业准备 偏置 拆卸 生产维护 维持生产 工件装卸 托盘交换系统 轮班 麻花钻 精加工刀具 粗加工刀具 型腔铣削 铣螺纹 铣平面 背镗 镗孔 六种操作模式：手动 MDI 自动 手轮 回零 编辑 键盘 处理机 模式切换开关 显示器 空运行 程序检查 空切循环 首件试切削
语法错误 动作错误 作业准备错误大意错误
CAD CAM CNC CAPP FMS CIM
HSS ATC MDI 刀具路径 后处理 型腔 三维线框模型 三维表面模型 三维实体模型 垂直的, 直立的, 水平的车床主轴箱 ; 立柱主轴刀库模态的绝对的增量的; 坐标象限, 四分仪垂直的, 直立的地平线的, 水平的床;headstock 主轴箱; colum 立柱;spindle 主轴;Magazine 刀库;Modal 模态的;absolute 绝对的 ;incremental 增量的;Coordinate 坐标;quadrant 象限, 四分仪;Rigidity 刚性，刚度;Turning 车削;Alloy 合金代码 编码补偿 赔偿伺服系统;Toolpath 刀具轨迹;Boring 镗孔; Stability 稳定性;
3. 指令, 说明书, 教育, 指导 instruction ; 手轮, 驾驶盘 hand wheel ;
机械装置 机构 机制 Mechanism ;转塔式换刀装置 T urret head ;矩阵 Matrix ;
锥度 Taper ; 多种用途的 多目标的 Multipurpose ; 重复定位精度 Repeatability; 公差 Tolerance ; 装配 Assembly ; 交点 intersection ;原点 origin; 命令 command; 矩形的，成直角的 Rectangular; 非模态的 Nonmodal; 二中择一 Alternative; 技术 T echnique; 使最优化 Optimize; 软钢 低碳钢 Mild steel ;激活 Activation;
传动带 Belt; 导轨 Slide;
4、立式加工中心; 卧式加工中心;
铣床; 刀具系统; 笛卡儿坐标系; 程序字符; 程序字; 准备功能; 硬质合金刀具; 铸铁 锻铁; 工件夹紧设备;
刀具长度补偿; 语法错误; 面铣刀; 铣螺纹; Face milling 铣平面;
5、三维空间Three dimentional gird 直角三角形Right triangle 斜角三角形Oblique triangle 程序段Program block 线性插补Linear interpolation 表面粗糙度 表面处理Surface finish 整体硬质合金刀具Solid carbide tool 设置盘setting dial 刀具半径补偿cutter radius compensation 步进电动机S tepping motors 非步进电动机Nonstepping motors 麻花钻Twist drill 型腔铣削Pocket milling 过切over cut 直流电Direct current
交流电Alternating current 空运行Dry run 锁定机床的空运行Machine lock dry run
6、Translate the following sentences into Chinese.
● The chain may be located on the side or the top of the CNC machine .these positions enable tools to
be stored away from the spindle and work. This will ensure a minimum of chip interference with the storage mechanism and a maximum of tool protection.
链式矩阵刀库可以安装在CNC 机床的侧面或顶部，这种位置可使存放的刀具远离主轴和共建，从而最大限度的减少切削对存刀装置的影响，同时更好的保护刀具。
● Ensure repeatability of a tool :center the tool in the spindle such that the tool’s relation to the work
is repeated every time the tool in used.
保证刀具的重复定位精度：将刀心定位于主轴中心，从而保证每次使用该刀具时其相对于工件位置是可重复的。
●
●
● the location of a CNC tool at any time is controlled by a system of XYZ coordinates called cartesian coordinates . 任何时候，CNC 刀具的位置都是由一个叫笛卡尔坐标的XYZ 坐标控制的。 In the early days of NC (before computer numerical control), the NC programmer actually had to
know how many rotations of an axis drive motor equated to an inch of linear movement.
在NC 发展的最初期（计算机数字控制出现之前），NC 程序员确实必须知道走一英寸直线长时各轴的驱动电动机转多少转。
● Many problems in CNC programming involve finding the Xand Y coordinates of tool motion based
on a given length and angle .these tasks can usually be accompolished by using basic right-triangle trigonometry.
在CNC 编程中常碰到根据已知长度和角度确定刀具运动的X Y 坐标问题，这些问题一般是通过基本的直角三角运算解决的。
● A progam format is a system of arranging information so that it is suitable for input to a CNC
controller 。
所谓程序格式就是一套组织信息的系统，其目的是使这些信息更适合输入到CNC 控制器。
● A program is a sequence of bolcks that describe in detail the motions a CNC machine is to execute in
order to manufacture a part .
程序是一组按顺序排列的程序段，它详细描述了为加工某个工件CNC 机床要执行的所有运动。 ● For this reason ,there are those in the industry who feel that manual programming is a thing of the
past .they contend that there are alternative to manual programming that eliminate the need to learn it .
基于这个原因，行业中有些人认为手工编程已经成为过去。他们认为既然有替代手工编程的方法，所以完全没有必要学习它。
● Though this is the case,the beginning programmer must grasp a basic understanding of manual
programming in order to continue on to the alternatives
即便在这种情况下，为了继续学习各种替代方法，初学者夜必须对于手工编程又基本的理解。
● This newwe form of CNC control allows the operator to input programs right at the machinein a
more understandable and graphic manner than with manual programming .
在这种新型的CNC 控制器上，操作员就可以直接在机床上输入程序，这种方式要比手工编程法更容易理解，图示性更强。
● It is difficult to determine precise date for any metal-cutting operation without knowledge of the
practicalities involved.
没有经过实践的知识，要确定任何金属切削加工的准确数据是很难的。
● For example, the condition of the machine, the power available, the rigidity of tooling and
working-holding arrangements, the volume of metal to be removed, the surface finish required, and the type of coolant be used are all factors that have to be considered when determining the appropriate speeds and feeds to be used.
例如，机床的条件、电力状况、刀具刚度及夹具情况、金属切削体积、表面粗糙度要求以及所用冷却液的类型等，都是确定适当的速度和进给时 要考虑的因素。
● Any complex project can be simplified by breaking it down into small pieces, this can make
seemingly insurmountable tasks much easier to handle
通过化整为零，任何复杂的项目都可以得到简化，这可以使表面看来不可逾越的任务变得简单起来。 ● The less a programmer leaves to the setup person’s imagination ,the less the chance there will be of a
mistake being made during the setup .
程序员留给作业准备人员的想象空间越小，作业准备过程中出现错误的机会就越小。
● A better approach is to creat a separate program called a subprogram ,which contains the
instruction for maching one pattern .a main program is also created calls the subprogram as many times as the machining sequence is repeated.
更好的方法是创建一个称为子程序的独立程序，该子程序包含加工某一形状的指令。同时编制一个主程序，需要加工该形状多少次，主程序就调用子程序多少次。
● Just as tool length compensation lets you gorget about each tool’s length as you write the program,so
does cutter radius compensation let you forget about the diameter of the tool as you write the program.
有了刀具长度补偿，编程的时候就不需要考虑刀具长度，于此相同，有了刀具半径补偿，编程的时候就不必考虑刀具直径。
● By varying the voltage input ,their speeds are infinitely variable as they rotate and so a constant
cutting speed can be maintained.
通过改变输出电压其速度可无极改变，这样就可以保持恒定的切削速度。
●
● The ability of the machine to produce continually accurate slide movement is called repeatability. 重复定位精度是机床的一个性能，它能使机床滑动部分连续地, 精确地运动。 A precise definition of repeatability is as follows : The maximum difference that can occur between
the shortest and the
Longest positions achieved in a number of attempted moves to any programmed target position.
重复定位精度的精确定义是：对于程序指定的任意目标位置，（机床）多次运动到此处后，其所到达的最远与最近位置之差的最大值即为其重复定位精度。
● One very good definition of setup-related task is ‘anything that happens from the running of the last
workpiece in the previous production run to efficiently running the first good workpiece in the next production run .
与作业准备相关工作由一个非常恰当的定义，即从前一个加工过程中最后一个工件的加工开始，到开始有效的加工下一个加工过程中第一个合格的工件为止，这期间发生的所有事情都属于作业准备的范
畴
● On the other hand ,many machining centers are equipped with pallet changer s,which allow the
operator to be unloading and loading one pallet while the machine is running another.
另一方面，许多加工中心都配有托盘交换装置，这样操作者就可以在机床加工一个零件的过程中完成另一个零件的装卸。
● The physical positions of the mode switch that are included as manual modes include manual or
jog ,handwheel and zero return.
模式切换开关的多个物理位置都被归为手动模式，其中包括手动、手轮和回零。
● Once the geometry is completed,then we can use a computer-aided manufacturing system to
generate an NC toolpath based on the CAD geometry.
几何形状一旦形成，我们就可以利用计算机辅助制造系统，根据CAD 的几何形状生成数控机床的刀具轨迹。
● The free flowing dry allowed you to take total control of all motion rates with the dry run motion
rate switch .this means when dry is turned on ,you will not be able to tell the difference between rapid motions and cutting motions.
在带进给运动的空运行中，通过空运行速率开关可以控制所有运动的速度，也就是说，只要一打开空运行开关，就看不出快速运动和切削运动的区别。
7、
● Translate the following sentences into english 乍一看，卧式加工中心的结构好像非常不同
at first glance ,it may appear that the c configuration of a horizontal maching center is dramatically different from that of a vertical maching center.
●
● 记住，任何运动都既可以绝对模式又可以增量模式编程 Keep in mind that any motion canbe commanded in either the absolute or incremental mode. 今天，由于矩形坐标系的出现，程序员不必为了对定位运动进行编程而去关心各轴的内部工作了。
Today, thanks to the rectangular coordinate system, programmers need not to concern themselves with the inner workings of each axis in order to command positioning movements.
●
● 进给率是指刀具切入共建材料的速度。The feed rate is the speed at which the cutter penetrates into the work material . 实际上，有了长度补偿，程序员在编程时就不需要考虑刀具的长度问题了。
in essence ，tool length compensation eliminates the need for a programmer to be concerned with a tool ‘s length as the program is written .
MDI 用来输入并执行CNC 命令，一次一条。CNC 命令一经执行就会丢失。
MDI is used to enter and execute CNC commands ,one at a time .Once the CNC command has been executed ,it is lost .
8、Translate the following passage into Chinese or English.
● Although high-speed steel (HSS) is used for small-diameter drills, taps, end mills, and spot drills,
the bulk of tooling for computer numerical control machine involves the use of cemented carbide. 尽管高速钢被用于小直径钻头、丝锥、绞刀、立铣刀以及点钻，但数控机床上大量使用的刀具都是超硬合金材料的。
● Unfortunately, CNC using companies vary dramatically with regard to what they expect their
operators to do. In some companies, the CNC operator does everything, including processing, tool design and fabrication, programming, setup, program loading, program verification, and actually
running production.
不幸的是，CNC 公司对于他们需要操作者做的事情有显著不同， 在一些公司里，CNC 操作者做每件事情，包括工艺、刀具设计、编程、安装、程序加载、程序检查以及实际运行生产。
● tool length compensation will be used for every tool in every program you write, so it mandatory
that you master this form of compensation. Cutter radius compensation is only applicable to milling cutters, and only when milling on the periphery of the tool.As stated several times to this point, cutter radius compensation allows you to work form the work surface as opposed to the cutter ’s center line, meaning you can save yourself a great deal of work if you understand cutter radius compensation. Note that the first two kinds of compensation apply to the cutting tools. Fixture offsets relate to your work holding setup.
刀具长度补偿将要被使用在你编写的每个程序的每把刀具，所以你必须要掌握这种补偿的类型。刀具半径补偿仅仅应用于铣刀，而且仅仅用在铣刀的外围。对于这一点就像陈述好多次那样，刀具半径补偿允许你将工件表面与刀具中线对应，也就是说，如果理解了刀具半径补偿，就可以节约大量的工作时间。
9、ask and answer
（1）、N0020 G18 G91 G00 X3.25 Y-8.75 F30 S500 ;
● ● ● how many program characters in this program block? how many program words in this block?
how many addresses in this block?
（2）、State the main elements of a vertical machining center.
Headstock 、spindle 、Colum 、splash guard 、table 、saddle 、bed 、automatic tools changer
（3）、State three modes of operation
G00 G01 G90 M99 T01
（4）、why learn manual programming? Page 42
（5）、which steps is included as the preparation for programming? Page 53
（6）why is the cutter radius compensation necessary?
（7） please write out six kinds modes of operation.
(8) what is subprogram? Do you think they are necessary ? why ?