Programming of CNC Machines. Ken Evans
When a Program Stop is commanded in the program by the program word M00, automatic operation is stopped and the LED on this button is turned on. This button does not have an ON/OFF function that affects the program stop condition. It is merely an LED indicator lamp to indicate when a program stop condition is active.
OPERATION
The keys in the Operation section (middle column) are used for manual operation of the machine during setup and initial startup. Their specific functions are described below:
REF (Reference)
Press the REF button to activate it. Then, pressing the X or Z buttons in the positive direction (X, Y or Z for machining centers) causes the machine to return to the Machine Zero position for each axis in relation to the machine coordinate system at the rapid traverse rate (maximum feedrate). The button must be held until the axis indicator LED is lit.
Jog
Pressing the JOG button activates a manual feed mode that allows the selection of manual feed movements along single axes X or Z (X, Y, or Z for machining centers). With the button activated, use the Axis/Direction (+ or –) buttons and the Feed Override dial to move the desired axis at the chosen feed rate. On some controls, Speed/Multiply is a rotary type switch that activates this function.
INC (Incremental)
Press the INC (Incremental JOG) button to activate the JOG mode in incremental steps. When the INC option is selected from the Operation Mode buttons, the incremental step selected by the Speed/Multiply buttons determines the magnitude of the displacement along the chosen axis in the selected direction. When one of the axes directional buttons is pressed and released, the movement will be as follows:
X1 = a movement of .0001 inch or .0025 millimeters (mm)
X10 = a movement of .001 inch or .0254 mm
X100 = a movement of .010 inch or .254 mm
X1000 = a movement of .100 inch or 2.54 mm
The buttons used to select the axis and the direction of movement (+, RAPID, and –) are located in the third column on the fourth row of the Operator Panel, as shown in Figure 2-6 for this controller.
For example, to displace the tool along the X-axis in a positive direction by the value of .010 inch, follow these steps.
• Press the INC button.
• Press the X100 button.
• Press the X button to activate the axis.
• Press the + button once.
Each time the button is pressed, a displacement of the selected value results.
If the JOG mode is selected when one of these buttons is activated, and the selected axis button is pressed and held in, the movement will occur at feed as indicated by the % Traverse Feed override dial.
Handle
Pressing the HANDLE button activates the manual handle feed mode for the selected axis. This handle is known as the Manual Pulse Generator (MPG). Pressing this button places the machine in the HANDLE mode, which enables manual control of axis movements [for X, Y, or Z; or for rotational axes 4 (A), 5 (B), or 6 (C)] by use of the handle after activating their respective axis buttons (Figure 2-7). For instance, press HANDLE, then press X, and then use the Handle to move to the desired position along the X-axis. By turning the handle clockwise, you can move the tool in a positive direction with respect to the position of the coordinate system. By turning the handle counterclockwise, the tool is moved in a negative direction with respect to the position of the coordinate system. The handle contains 100 notches, each of which corresponds to an increment (distance to be moved). Turning the handle, you can feel the displacement from one notch to the next.
To set the magnitude for the distance to be moved, press one of the Speed/Multiply buttons as described in the INC section above.
Caution: If the handle is rotated quickly while the magnitude is set at X100 or X1000, the tool will move at a rapid feed rate and a crash could occur!
When the HANDLE mode is selected, the incremental step selected by the Speed/ Multiply buttons determines the magnitude of the movement along the chosen axis in the selected direction. Each button setting corresponds with the scale of the hand-wheel. One full revolution of the hand-wheel (360°) corresponds to 100 units on the scale. On the button X1, the X means “times” the minimum increment. In manual control, you must use the + or – buttons to identify axis direction as well as to determine the axis of displacement.
Usually, X1 is used when you are precisely dialing-in the zero of the workpiece and when you are determining the tool length offset. For example, if you need to move the machine table with respect to the tool by 1.00” along the X-axis in a positive direction, follow these steps:
• Press HANDLE mode button.
• Press the axis directional button +X.
• Press the SPEED/MULTIPLY button X10.
• Turn the handle one full revolution (100 units) and then check the value of the displacement on the screen. It should indicate a movement of 1.00 inch.
Figure 2-7 Manual Pulse Generator (MPG) HANDLE Courtesy FANUC FA America
X, Y, Z
The X, Y, and Z buttons correspond with each of the linear axes. When one is pressed, that axis becomes active for manual positioning by any of the manual modes.
4, 5, 6
The 4, 5, and 6 buttons correspond with each of the rotary axes. When one is pressed, that axis becomes active for manual positioning by any of the manual modes.
AXIS DIRECTION
+ and −
These buttons are used to select the manual feed axis direction. Pressing these buttons executes movement along the selected axis in the selected direction relative to the machine coordinate system—by Jog feed (or INC feed) or HANDLE—when the corresponding button is set to ON in the jog feed mode (or INC feed mode). The same is true for each of the linear and rotational axis buttons. As long as the button is held, the axis will move at a feed rate determined by the Feed Override dial or INC setting until released.
Rapid
After selecting the desired axis and pressing the Rapid button simultaneously with the + or – button, the machine will move along that axis at rapid traverse until released.
Caution: Prior to activation, be sure the part, fixture, or clamping devices that are in the chosen path are not going to interfere. The axis will move at a rapid feed rate and a crash could occur!
The Operator Panel in Figure 2-2 includes a Feed/Rapid % override dial you can use to control the rapid feed rate. This dial is used to reduce the rapid feed rate (G00). If it is positioned at 100, it corresponds to 100% of the rapid feed rate that the machine can generate. When override buttons are used, they are commonly incremented in steps of 10, 25, 50, and 100%.
SPINDLE
The spindle buttons are used exclusively during the machine’s manual operation for setup functions. The descriptions below explain their specific function:
SPDL CW
By pressing the SPDL CW button while in one of the operation modes REF, JOG, INC, or HANDLE, the spindle will start rotation in