<p>I'm getting wavy lines on the first layer only in both the x and y direction identically.  The first layer is 0.4 mm with a 0.4 mm tip. The other layers are 0.2 mm.  I've tried changing the Z offset all the way from -1.2 to 0.5 mm.  I've tried changing the hot end leveling the heated bed.  None of these changes affected the wavy lines.  The waves have about a 1 mm period.  The printer is a German RipRap.  The material is ABS.  The heated bed is 110&nbsp;&deg;C.  I've tried the hot end at 220&nbsp;&deg;C and 240&nbsp;&deg;C.  So far, nothing has changed the waves.  </p>

<p><a href="https://i.stack.imgur.com/e74SF.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/e74SF.jpg" alt="enter image description here"></a></p>

The general recommendation for layer height is to go no thicker than 75% of the nozzle diameter. Your post states 0.4 mm layer height with a 0.4 nozzle, exceeding the recommendation.
If your first layer is dropped to 0.3 mm, you'll fall into the recommendation, but the thickness is a reference for ALL layers.