Flattening the bottom
The bottom of the mug, while flatter than before, is not perfectly flat and is therefore not suitable for printing yet. However, there is a way to use the scale operator in Edit Mode to make a flat bottom, by carrying out the following steps:
Jump to the front view (Numpad 1).
Enter Edit mode (Tab).
Clear the selection (A).
Use the Box Select operation (B) to select the bottom few layers.
Without touching the mouse carry out the following steps:
Begin the Scale (S) operation.
Press Z to lock the scale operation to the z-axis.
Type
0
(zero) to scale by a factor of zero.Press Enter to end the scale operation.
Rotate the view and notice that all the points that were there before are still there, they are all just on the exact same z level making a perfectly flat bottom for printing.
Remember to save (Ctrl + S).