======MQL - Minimum Quantity Lubrication======

{{youtube>0NRn-5vOnkU?large}}

myCNC software allows the user to implement MQL, or Minimum Quantity Lubrication, on their machines. 

MQL is a process in which tiny drops of high-quality aerosol lubricant are sprayed over the cutting tool and the material, providing lubrication at extremely low rates of lubricant use. This allows for a greatly reduced fluid usage (with the workpiece being nearly dry throughout the lubrication process) as opposed to typical flood setups, resulting in a greener environmental impact and eliminating the need for fluid disposal. 

MQL is available in myCNC software by going into the Step/Dir Coolant control tab within User Settings, where you can set the coolant rate. 

{{:mycnc:mql-002-user-settings.png}}

The fine-tuning is done through the built-in PLC procedures, with the setup described in detail in the [[mycnc:independent_pulse_generator|Independent Pulse Generator]] manual. 

In certain profiles (such as the X1366M4E), the MQL functionality is accessible via the main myCNC screen (in the Coordinates section):

{{:mycnc:mql-002-main-screen-x1366m4e.png}}

This on-screen element displays the current Flood Coolant Rate (global variable #8133). 

A series of hotkeys can also be assigned within the myCNC software to quickly control the flood rate. This can be done by going into Settings > Config > Panel/Pendant > Hotkeys, and assigning two new keyboard shortcuts with the following actions:

<code>cnc-gvariable-inc-8133</code>

and 

<code>cnc-gvariable-dec-8133</code>

The following screenshot shows an example configuration of two key bindings to increase and decrease the flood rate: 

{{:mycnc:mql-003-hotkeys.png}}

This will allow the user to quickly change the coolant flood rate from their keyboard.

====MQL Setup in myCNC software====

<code>This section has been copied from the Independent Pulse Generator manual linked above.</code>

=== Software PLC for MQL ===
The rate, ratio and acceleration can be set up in the Software PLC, as well as in the User Settings widget (the Step-Dir Coolant Control section). 

"HANDLER_INIT.plc" procedure is started just after the configuration is sent to the myCNC controller. A few lines to set up the Frequency generator can be added there.

++++ Show HANDLER_INIT code |
<code C HANDLER_INIT.plc>
main()
 {
 gvarset(60000,1);//run Servo ON procedure

 gvarset(8131, 8000); //set Frequency acceleration
 gvarset(8132, 1359); //set Ratio
 gvarset(8133, 0);    //Off the Generator.

 exit(99);
};
</code>
++++

=== Hardware PLC for MQL ===

In addition to the software HANDLER_INIT PLC, certain hardware PLC procedures must be changed for the Minimum Quantity Lubrication to be set up.

Function ''coolant_motor_start()'' is added to the ''mill-func.h'' file:

++++ Show mill-func.h code |
<code C mill-func.h>
coolant_motor_start()
{
  timer=10;do{timer--;}while(timer>0);

  gvarset(8131,1000000); //acceleration
  timer=10;do{timer--;}while(timer>0);

  x=gvarget(8133);//get the speed (frequency)
  k=gvarget(8132);//get the ratio

  x=x*k; //calculate the RAW frequency
  gvarset(8130,x); //send the raw frequency to the register
  timer=30;do{timer--;}while(timer>0); //wait a time for the frequency value to be delivered
};
</code>
++++

''M08.plc'' procedure which starts the coolant motor would be the following (//note the inclusion of mill-func.h at the beginning of the code//):

++++ Show M08 code |
<code C M08.plc>
#include pins.h
#include mill-func.h

main()
{
  gvarset(7372,1);
  portset(OUTPUT_FLOOD); //
  coolant_motor_start();
  exit(99);	//normal exit 
};
</code>
++++

A procedure ''M09.plc'' to stop a coolant motor is simpler - we simply need to write "0" to the raw frequency register.

++++ Show M09 code |
<code C M09.plc>
#include pins.h
main()
{
  gvarset(7373,0);
  gvarset(7372,0);

  portclr(OUTPUT_FLOOD);
  portclr(OUTPUT_MIST);

  gvarset(8130,0); //stop the pulse generator
  timer=30;do{timer--;}while(timer>0); //wait a time for the frequency value to be delivered
  exit(99);	//normal exit 
};

</code>
++++

This concludes the software setup for MQL within the myCNC software.