TABLE OF CONTENTS Obsolete subject - chapter included for compatibility purposes
Relationships between various reference points in CNC programming are always expressed as preset numeric values. More often than not, these numbers, these specific values, are required well before actual machine setup takes place. During programming, many dimensions are known exactly, others are known approximately and there are also those that are not known at all. Some known dimensions are subject to variations between jobs. Without any corrective facility available to the programmer, it will be almost impossible to setup the machine precisely and efficiently. Fortunately, modern controls offer many features to make both programming and machine setup an easier, faster and more precise activity. A number of coordinate systems, offsets and compensations are typical support tools used in programming for corrective purposes.
One of the oldest programming methods available is called position compensation. As the name suggests, using position compensation functions, the actual tool position is compensated relative to its theoretical or assumed position.
It is only one of several corrective methods available to the programmer. On modern CNC systems, this method is available for compatibility with older programs. Today, this technique is obsolete. It has been replaced by the much more flexible Work Offsets (Work Coordinate System), described in the next chapter. This chapter describes some typical programming applications that can benefit from using the old-fashioned position compensation method.
The main purpose of position compensation is to correct any differences between machine zero...
