Program proving

Abstract

Once a part program has been written and the supporting documentation prepared, it is loaded into the machine and the documentation supplied to the operator. The program and all relevant information must be checked, either by viewing the program displayed on the MCU screen, or by using a software package on a computer and then proving the program on the machine. Errors that may be detected include the following:

• errors in the part program:

  • typing errors

  • incorrect sign

  • program omissions;

• errors in the supporting details

  • tool offsets

  • feeds and speeds

  • centres of arc.

Graphic simulation (see below) compares the programmed shape with the required component shape (Figure 12.1). It doesn’t check for correct speeds, feedrates, tools and possible crash conditions. The part program must be proof-tested on the machine by any of the following methods before production starts; in fact, it is a good idea (and often necessary) to prove the program by more than one method.