Copper rub out operation is the second of the copper milling operations. It may follow insulation milling. The difference is that the rub out completely removes copper from the places where it’s not supposed to be, whereas insulation milling only isolates the traces from the copper layer. Remaining unconnected copper alters electrical properties of the circuit board, which is often undesired in the layouts involving radio frequencies or high voltages.

As rub out is an additional step, which is not always required, there’s an option in Settings – Rub out to skip it. This option is turned on by default. In this case, the rub out stage is skipped and the wizard continues to the next step. Rub out can still be selected manually, though.

Rub out screen is very similar to insulation milling screen, the only difference being the tool paths. So all of the same controls work on this screen as well, namely you can zoom in and out in one of the following ways:

  • click on the corresponding icons in the upper left corner of PCB design pane
  • hold Ctrl (or Cmd on Mac OS X) button and use the scroll wheel of your mouse
  • press Ctrl+= (or Cmd+=) to zoom in, or Ctrl+- (Cmd+-) to zoom out

You can select, which tool paths are going to be milled (this is useful if you didn’t like the result in some places and want to have another go there). Tool paths can be selected with mouse. Selected tool paths can be enabled and disabled with toolbar buttons or with keyboard shortcuts: Ctrl+E (or Cmd-E on Mac OS X) to enable, and Ctrl+D (or Cmd+D) to disable. Shortcut Ctrl+A (Cmd+A) selects all tool paths.

For your convenience offsets that were entered on previous steps can be checked (and should it be necessary edited) in Offsets popover. The same way all of the relevant settings can be accessed and changed in Settings popover.

If you wish to have a look at G-Code that will be send to the machine, you can press a button with wrench icon in the toolbar.

When you are happy with all of the settings, press Run button. cirQWizard will send generated G-Code to the machine.