How to control positioning motion splitting
The CAM-POST Questionnaire provides settings that can split rapid positioning moves based on the direction of one particular axis (typically the Z-axis). For example, XYZ positioning moves where the Z-axis is plunging are split in two motions: XY followed by Z, whereas positioning moves where Z is retracting are output as Z first, followed by XY. However, these settings may not be appropriate for 5-axes positioning moves in RTCP, where all axes must position simultaneously.
The SAFETY command allows programmers to control when and how safe positioning analysis should be applied. This command can be included in a post-processor macro, or inserted in the Cutter Location file via a PP Instruction (CATIA), a User-Defined UDE (NX), a Custom CL Command (Creo), or a Manual Entry output as code (Mastercam).
The syntax of the SAFETY command is summarized below.
Any combination of axis identifier minor words or couplets can be used, interceded with the word NEXT to indicate a block purge. Coding the word NEXT as the first argument causes safe positioning analysis to be executed only once, on the next rapid move following the SAFETY command. If NEXT is omitted after the major word, motion splitting will be applied on all upcoming rapid moves. The SAFETY/OFF command can be used to cancel positioning analysis settings currently in effect.
In the examples below, different SAFETY commands are coded after a tool change. The captures illustrate the resulting motion data output by the post-processor for each case. As NEXT is used as a first argument, each command will remain in effect only until the next rapid position. The highlighted NEXT minor words indicate when block purging is required to occur.
SAFETY / NEXT, XAXIS, YAXIS, AAXIS, BAXIS, NEXT, ZAXIS
SAFETY / NEXT, XAXIS, YAXIS, NEXT, ZAXIS, AAXIS, BAXIS
Benefit to User
Control rapid positioning splitting directly from the CAM system.
For more information or comments, please do not hesitate to contact Phil at TechTipTuesday@icam.com