Mastercam Post Processor Editing [upd] đź”–
: The post processor is typically stored in a .pst file containing logic and variables that format the NCI (binary toolpath data) into text G-code.
Modern controls require activation codes for high-speed look-ahead profiling (e.g., FANUC AICC G05.1 Q1 or Haas G187 ). You can automate this by adding conditional logic inside the ptlchg$ block to read Mastercam's operation parameters and output the corresponding code before the tool enters the material. Managing Coolant Options
Mastercam post processor editing is a powerful way to customize and optimize your machining operations. By understanding the basics of post processor editing and following best practices, you can unlock the full potential of your CNC machines and improve your manufacturing efficiency. Whether you're a seasoned CAM professional or just starting out, mastering post processor editing will help you take your machining operations to the next level.
: Always create a backup copy of your post processor before making any changes. Common Variables :
Eliminating errors that cause machine crashes or downtime. The Language of Editing: MPL (Mastercam Post Language) mastercam post processor editing
Formats data types, defines prefixes (like 'X', 'Y', 'Z'), and sets rounding tolerances.
| | Find this variable/block | Change to this | | :--- | :--- | :--- | | Remove "N100" lines | omitseq$ | yes$ | | Remove "O0000" (program number) | pprog$ block | Comment out "O", progno$ | | Force G43 H on every tool | psof$ or ptlchg$ | Ensure *tlngno$ is present, not commented | | Turn off the G43 line entirely | psof$ | Look for "G43" , add # in front of the line | | Add a custom comment (SAMPLE) | pheader$ | " (SAMPLE)", e$ | | Change G28 to G91 G28 | pretract block | Look for "G28" ; change to "G91" , "G28" | | Output decimals for inches only | fs2 definitions | Create one format without decimal point for integers. | | Suppress the "D" comp on lathe | ptoolend$ | Find *tldia$ or cc_pos$ ; comment it out. |
A lightweight alternative. You can download custom user-defined language (UDL) files for Mastercam MP syntax highlighting.
Read the code carefully in a text editor or simulation software (like Cimco Edit) to ensure all G-codes are in the correct format. : The post processor is typically stored in a
Add custom logic or modify feed rate commands. Debug: Utilize comment lines to test logic. ⚠️ Important Precautions: Always Backup
Editing a Mastercam Post Processor ( .pst and .psb files) isn’t just a technical skill—it’s a survival skill for any shop that wants to move beyond generic G-code.
A forum user wanted an M01 (optional stop) after every tool change. The solution requires editing two specific post blocks: psof$ (start of file) and ptlchg$ (tool change).
To begin editing, you need the right tools and a safety-first mindset. Managing Coolant Options Mastercam post processor editing is
: While standard text editors work, Mastercam Code Expert is recommended for its built-in recognition of variables and operators.
The best post processor is invisible. You generate the code, press cycle start, and walk away. If you have to touch the G-code, you need to edit your post.
Create a simple file in Mastercam with common operations (Contour, Pocket, Drilling).