TABLE OF CONTENTS Dwell is a technical name for a pause in CNC programs - it is an intentional time delay applied during program processing, at the machine. In this time period - specified in the program - any axis motion is stopped, while all other program commands and functions remain unchanged (function normally). When the specified time expires, control system resumes processing of program block immediately following the dwell command.
Programming a dwell is very easy and can be quite useful in two main applications:
During actual cutting,
when the tool is in contact with material
For operation of machine accessories,
when no cutting takes place
Each application is equally important to programmers, although the two are not used simultaneously.
When cutting tool is removing material stock, it is in contact with the machined part. A dwell can be applied during machining for a number of reasons. If the spindle is running, the spindle speed (r/min) is very important.
In practice, the application of dwell during a cut may be used for breaking chips while drilling, grooving, countersinking, counterboring, or parting-off. Dwell may also be used while turning or boring, in order to eliminate any physical marks left on the part by end thrust of the cutting tool. This thrust is the result attributed to various tool pressures during cutting. In many other applications, the dwell function is useful to control cutting feed deceleration on a corner during very fast feedrates, for example. This...
