09 use a grid helper

To copy objects along a line angled differently to the default X,Y,Z we can create a new UCS Grid helper. From the Helpers menu select Grid and drag the square form into a viewport. Rotate and move the Grid to the angle and position in which you would like the new UCS to operate. You have to make the UCS active by rightclicking it and selecting Activate Grid. Finally, the viewport you wish to work in must also be activated. Click on the active view name at the top left of the viewport and from the dropdown go to Extended Viewports>grid and then whichever view you require.