A fixture offset is a datum coordinate that you specify and then apply to a copy of a toolpath. This enables you to shift the toolpath—without needing to recalculate it—so it can be machined in a new position. A fixture offset also enables you to make last-minute adjustments to the position of a toolpath, as you can use the machine tool controller to change the values of the fixture offset on the tape file.
If you want to machine the same toolpath more than a couple of times, you should use the Move option on the Toolpath Transform tab.
PowerMill has two levels of Fixture offset tabs that have a parent-child relationship:
- This Fixture Offset dialog is a child of the parent Fixture offset tab. It inherits all the fixture offsets already specified in the parent Fixture offset tab.
When you have created an NC program, the child Fixture offset dialog associated with NC program does not continue to inherit changes you make in the parent Fixture offset tab. To inherit subsequent changes, select the Reset to Default button.
- The parent Fixture offset tab does not inherit changes you make in the childFixture offset dialog. You can display the parent Fixture offset tab by, in the Explorer, right-clicking NC Programs and selecting NC Preferences > Fixture offset tab.
To display this dialog, in the Explorer, right-click an NC program and select Edit > Fixture Offsets.
This dialog contains the following:
Name — Enter the name of the fixture offset.
The names you specify for the fixture offsets must be recognised by the option file that writes the NC program. For example, an option file for a Fanuc machine tool controller recognises G-codes (for example, G55, G56 and G57).
Add Fixture Offset — Click to add the fixture offset to the Fixture offset table.
Fixture offset table — The table displays each fixture offset and its coordinates. To enter or change a coordinate, enter the coordinates in the X, Y, or Z boxes.
You can leave the X, Y and Z boxes blank, and specify the coordinates on the machine tool controller.
Reset to default — Click to reset to the fixture offsets created in the parent Fixture offset tab. Any edits or additional fixture offsets created in the child Fixture offset dialog are deleted.
Reset Fixture Offset — Click to reset the coordinates of the selected fixture offset to 0.0.
Delete Fixture Offset — Click to delete the selected fixture offset from the Fixture offset table.