Protect Your Tools

Since the very first Haas control was released there has been a provision for the monitoring of tool (spindle) load with facilities for the operator to set a limit for each tool, found in the Current Commands display and pressing page down until the screen is displayed.

Entering a maximum value would cause the machine to either Alarm, Feedhold or Beep depending on setting 84 Tool Overload Action. This standard control feature can help to prevent machine damage through tool failures, unexpected material differences (cold spots etc.) or programming errors.

However with the release of 9.43 software, this feature was further enhanced with the inclusion of Autofeed - a function that automatically limits the feedrate based on the tool load.

To use this feature, select AUTOFEED in Setting 84 and specify load limits for the tools that will be used. If, during a feed, the tool load exceeds the tool load limit, the AUTOFEED feature will automatically override the feed rate (reduce it) down to the percentage specified by parameter 301 (e.g. 1%) at the rate specified by parameter 300 (e.g. 20% per second.) 

If the tool load later falls below 95% of the tool load limit percentage, the AUTOFEED feature will automatically override the feed rate (increase it) back to the feed rate that was in effect at the start of the feed at the rate specified by parameter 299 (e.g. 10% per second.) These automatic adjustments will be made in 0.1 second increments.


  • When tapping (rigid and floating), the feed and spindle overrides will be locked out, so the AUTOFEED feature will be ineffective (although the display will appear to respond to the override buttons.)
  • The AUTOFEED feature should not be used when doing thread milling or using auto reversing tapping heads.  Refer to Chapter III-Part 15 of the VF-SERIES OPERATORS MANUAL.
  • The last commanded feed rate will be restored at the end of program execution, or when the operator presses RESET or turns off the AUTOFEED feature.
  • The operator may use the feed rate override buttons while the AUTOFEED feature is active. As long as tool load limit is not exceeded, these buttons will have the expected effect and the overridden feed rate will be recognised as the new commanded feed rate by the AUTOFEED feature.  However, if the tool load limit has already been exceeded, the control will ignore the feed rate override buttons and the commanded feed rate will remain unchanged.
  • Parameter 299 AUTOFEED-STEP-UP specifies the feed rate step-up percentage per second and should initially be set to 10.
  • Parameter 300 AUTOFEED-STEP-DOWN specifies the feed rate step-down percentage per second and should initially be set to 20.
  • Parameter 301 AUTOFEED-MIN-LIMIT specifies the minimum allowable feed rate override percentage that the AUTOFEED feature can use and should initially be set to 1.