Inverse Time Feed Rate

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Inverse Time Feed Rate

In 4 Axis operations you can set the your post processor to output feedrates in Inverse Time format.  Once this is set, then all 4 and 5 axis motions will be processed with this feedrate being output.  

 

tog_minusThe way Inverse Time Feedrate is computed:

1.First the distance traveled by the tool is computed for each move = dist  

2.Then the time taken for traversing the move is computed thus:
timeForTravel = dist / cutFeedRate;

3.Then the inverse time feedrate is = 1.0/timeForTravel;

4.And it is output for each move if different from the previous move.  
tog_minusTo enable Inverse Time Feedrate

You do not need to edit your toolpath operations to output the Inverse Time Feedrate format!  It is done automatically once it is enabled in your post processor.  Follow these steps to enable the Inverse Time Feedrate format in your post:

1.From the Program tab under Machine Setup, select the Post icon to display the Set Post-Processor Options dialog.

2.For Current Post Processor, select your post.

3.Pick the Edit button to the right.  This will display the Post-Process Generator dialog.

Launch the Post-Process Generator

Launch the Post-Process Generator

4.From the left side pane, select the Feedrate section.

Post-Process Generator / Feedrate / Inverse Time

Post-Process Generator / Feedrate / Inverse Time

5.On the right side pane, under Block Format, check the box next to "Output inverse time feedrate for 4 & 5 Axis motions".

6.For On Code, enter G93.

7.For Off Code, enter G94.

8.Pick Save As to save your (*.spm) post.  

Hint!Anytime you make an edit to your post (*.spm) file, it is recommended that you select Save As to save your post file to a unique name and to a unique folder where you can find it (such as your Desktop or shared Network Drive).

9.With your revised post set as your Current Post Processor, pick OK to close the Set Post-Processor Options dialog.

Hint!If you do not see your revised post in the Current Post Processor list, select the "..." button to the right of "Folder where post processor file are located" and navigate to the folder where you save your post (*.spm) file.  It should then appear in the list.

10.Test the revised post with a sample 4 or 5 Axis toolpath operation.