The Basics Of Computer Numerical Control(3)
Key concept number two: Know your machine
A CNC user MUST understand the makeup of the CNC machine tool beingutilized. While this may sound like a basic statement, a CNC user must be ableto view the machine from two distinctly different perspectives. Here in keyconcept number two, we will be viewing the machine from a programmer'sperspective. Much later, in key concept number seven, we will look at themachine from an operator's viewpoint.
Basic machining practice - the key to success with any CNC machine
Many forms of CNC machines are designed to enhance or replace what iscurrently being done with more conventional machines. The first goal of any CNCbeginner should be to understand the basic machining practice that goes intousing the CNC machine tool. The more the beginning CNC user knows about basicmachining practice, the easier it will be to adapt to CNC.
Think of it this way. If you already know basic machining practice as itrelates to the CNC machine you will be working with, you already know what itis you want the machine to do. It will be a relatively simple matter oflearning how to tell the CNC machine what it is you want it to do (learning toprogram). This is why machinists make the best CNC programmers, operators, andsetup personnel. Machinists already know what it is the machine will be doing.It will be a relatively simple matter of adapting what they already know to theCNC machine.
For example, a beginner to CNC turning centers should understand the basicmachining practice related to turning operations like rough and finish turning,rough and finish boring, grooving, threading, and necking. Since this form ofCNC machine can perform multiple operations in a single program (as many CNCmachines can), the beginner should also know the basics of how to processworkpieces machined by turning so a sequence of machining operations can bedeveloped for workpieces to be machined.
This point cannot be overstressed. Trying to learn about a particular CNCmachine without understanding the basic machining practice related to themachine would be like trying to learn how to fly an airplane withoutunderstanding the basics of aerodynamics and flight. Just as a beginning pilotwill be in for a great number of problems without understanding aerodynamics,so is the beginning CNC user have difficulty learning how to utilize CNCequipment without an understanding of basic machining practice.
Learning about a new CNC machine - the key points
From a programmer's standpoint, as you begin to learn about any new CNCmachine, you should concentrate on four basic areas. First, you shouldunderstand the machine's most basic components. Second, you should becomecomfortable with your machine's directions of motion (axes). Third, you shouldbecome familiar with any accessories equipped with the machine. And fourth, youshould find out what programmable functions are included with the machine andlearn how they are programmed.
While you do not have to be a machine designer to work with CNC equipment,it is important to know how your CNC machine is constructed. Understanding yourmachine's construction will help you to gauge the limits of what is possiblewith your machine. Just as the race car driver should understand the basics ofsuspension systems, breaking systems, and the workings of internal combustionengines (among other things) in order to get the most out of a given car, somust the CNC programmer understand the basic workings of the CNC machine inorder to get the most from the CNC machine tool.
For a universal style slant bed turning center, for example, the programmershould know the most basic machine components, including bed, way system,headstock & spindle, turret construction, tailstock, and work holdingdevice. Information regarding the machine's construction including assemblydrawings is usually published right in the machine tool builder's manual. Asyou read the machine tool builder's manual, here are some of the machinecapacity and construction questions to which you should find answers.