Haas G150 Pocket Milling: How to Use It Like a Pro

I must admit I used to think this feature was a waste of time. But I didn’t realise that some folks don’t have a CAM sytem so long hand programming would take ages.

CNC Training Call David: 07834 858 407

Dirty old beast but then so am I and I still have my uses.

The Haas G150 pocket milling command is a versatile and powerful feature for CNC machinists looking to machine pocket shapes. By defining a pocket’s geometry in a subprogram and then using G150 to call it, you can streamline your code.

What is Haas G150 Pocket Milling?

The G150 G-code command on Haas CNC mills is designed for general-purpose pocket milling. It allows machinists to mill out complex pocket shapes by defining the geometry once in a subprogram, then calling it using a single line of code in the main program.

G150 Explained

The G150 command uses a range of parameters to control the milling operation:

• P – Subprogram number that defines the pocket shape, can be internal or external (but not on my old machine)
• X, Y – Starting location (usually the pre-drilled entry hole)
• Z – Final pocket depth
• I or J – Step-over distance in X or Y direction, make sure you only include one as you will get an alarm
• K – Finish allowance for a final pass
• Q – Incremental Z depth per pass
• R – Height for pocket, depth is from here
• F – Feed rate
• D – Tool diameter offset register (for G41/G42)
• L – Optional repeat count with incremental positioning

Writing the Pocket Geometry Subprogram

The subprogram specified by the P code outlines the pocket’s perimeter. Important rules:

• Must be a closed loop (start and end at the same point)
• Max 40 moves (linear or circular)
• Start move should go from entry hole to the boundary
• Final move must not go back to the entry hole
• Use cutter comp G41 with lead-in/lead-out moves add to cycle.

This example it really simple try it out first just to make sure all is ok. You can then hit it with a much more complex shape.

On older controls you have to put the shape in an external sub program like O500 you can’t use internal sub routine.