Post Processor Lessons - Lesson 1

Post Modification Lesson 1: Enabling Debug and Deleting Output

In this lesson we will cover making some common modifications to the header block that may be required for your machine tool. We are going to use the following files for this lesson:

Machine File: BC_3x_Mill

Post Processor: BC_3x_Mill.BCPst

Part File: Post Guide – Lesson 1.bbcd

This test file includes multiple machining features. Each feature contains multiple operations to complete the part. It is important when creating, customizing, or modifying post processors that you test all machining scenarios to ensure the post processor is working fully on the machine tool.

This includes but is not limited to:

Profile Milling with and without machine cutter compensation
All drilling canned cycles supported by the software and the machine
Tool Change blocks
Subprogram output
File ending

The start of the NC program is referred to as the “Header” and below you can see an example of the default header output.

O0100 (PROGRAM NUMBER)

(PROGRAM NAME - POST GUIDE - LESSON 1.NC)

(POST - BC_3X_MILL 3-AXIS GENERIC FANUC)

(DATE - FRI. 04/21/2017)

(TIME - 04:36PM)

(BEGIN PREDATOR NC HEADER)

(COORD_SYS 1=X0 Y0 Z0)

(MTOOL T1 S1 D0.25 C0. A0. H2.5)

(MTOOL T2 S1 D0.25 C0. A0. H2.5)

(MTOOL T3 S4 D0.4375 C0. A60. H2.75)

(MTOOL T4 S4 D0.375 C0. A118. H5.)

(MTOOL T5 S1 D0.375 C0. A0. H2.25)

(MTOOL T6 S1 D0.5 C0. A0. H3.)

(MTOOL T7 S1 D0.5 C0. A0. H3.)

(SBOX X0. Y-2.5 Z-0.375 L3.5 W2.5 H0.375)

(END PREDATOR NC HEADER)

For the 1st modification we will alter the header to remove the following items and then we will add some new information.

Items to remove:

% sign
Post Processor Name line
Time

Lesson 1 - Step 1:

Open the post processor file in your text editor. (We recommend using Notepad ++ for this as it is a no cost text editor that works well).

Lesson 1 - Step 2:

Search or scroll down to Post Block 26. This is the Debugging Post Block. Change the “debug_off” variable to “debug_on” and save the file.
This turns on the post debugging. It will help us locate what Post Block is outputting the lines of code we wish to modify.

Lesson 1 - Step 3:

Run the post processor to generate the gcode. Open the Gcode in your text editor and I recommend you tile the two windows so you can see the post processor output (Gcode) and the post processor file itself at the same time as shown in the image below.

Lesson 1 - Step 4:

Notice now the extra entries for the Debugging comments. These comments tell us which Post Blocks are responsible for the output we are seeing in the NC code. (See Below)