Course: PMT 250 Multi-Axis CNC Programming (Section 060)

HAAS ST20Y Lessons

Programming the Y Axis
Programming the Y Axis
- The Y-axis on lathes moves in the opposite direction of what we learned when programming a vertical mill.

- The positive direction is towards the operator.

The cutting tool is positioned towards the front of the machine.

- The negative direction is away from the operator.

The cutting tool is positioned towards the back of the machine.

- An incremental movement of the Y-axis uses a V code

Example - G00 V-.500

This will move the axis towards the back of the machine.

- When milling arcs in a G02 or G03 you can program with a J or and R value.

Y-Axis Travel limits

- The ST20Y CNC lathe has a Y-axis travel total of 4 inches.

- There are 2 inches of travel in both the positive and negative direction.

- The Y-axis is at 2.00 in the positive direction or above the part. (Notice the ways on the turret)

- The Y-axis is at the negative 2.00 position or behind the part. (Notice the ways on the turret)

X-Axis Travel Limits
- The X-axis can travel .400 below the center line of the part.

- In the picture below, the red box shows the X-axis travel limit for a ST20Y lathe.

- If you need to machine below that limit you must use a XC plane or G112.

Program Structure for C-Axis Programming

Regular start of a lathe program

M154 (Engage C-axis)

G98 (Inches per minute feed)

G97 P1250 M133 (Starting the live tooling motor)

M15 (Spindle brake off)*

M19 P60. (Orient spindle)*

M14 (Spindle brake on)*

Ending

M135 (Live tooling motor off)

M155 (C-axis disengage)

*These 3 lines are used to rotate spindle to the next angle.