|You must purchase the Rotation and Scaling option to use this G-code. A 200-hour option tryout is also available; refer to Option Tryout for instructions.|
The control always uses a scaling center to determine the scaled position. If you do not specify a scaling center in the G51 command block, then the control uses the last commanded position as the scaling center.
With a scaling (G51) command, the control multiplies by a scaling factor (P) all X, Y, Z, A, B, and C end points for rapids, linear feeds, and circular feeds. G51 also scales I, J, K, and R for G02 and G03. The control offsets all of these positions relative to a scaling center.
There are (3) ways to specify the scaling factor:
G51 affects all appropriate positioning values in the blocks after the G51 command.
These example programs show how different scaling centers affect the scaling command.G51 No Scaling Gothic Window:  Work coordinate origin.
The first example illustrates how the control uses the current work coordinate location as a scaling center. Here, it is X0Y0Z0.G51 Scaling Current Work Coordinates: The Origin  is the work origin and the center of scaling.
The next example specifies the center of the window as the scaling center.G51 Scaling Center of Window:  Work coordinate origin,  Center of scaling.
The last example illustrates how scaling can be placed at the edge of tool paths as if the part was being set against locating pins.G51 Scaling Edge of Tool Path:  Work coordinate origin,  Center of scaling.
Tool offsets and cutter compensation values are not affected by scaling.
For canned cycles, G51 scales the initial point, depth, and return plane relative to the center of scaling.
To retain the functionality of canned cycles, G51 does not scale these:
The control rounds the final results of scaling to the lowest fractional value of the variable being scaled.