title: Gimbal lock at y axis 90 degrees
body: <p>I found a problem with rotations.
  Using the transform controls helper, if I rotate a mesh on the Y axis, when I reach 90 degrees everything is flipped by -180 degrees.</p>
  
  <p>I think this is due to the software avoiding gimbal lock, how to avoid it?
  <strong>That is, I would like the x- and z-angles to remain 0 degrees in the display.</strong></p>
  
  <p>I tried even on the threejs editor (<a href="https://threejs.org/editor/" rel="nofollow noreferrer">https://threejs.org/editor/</a>) and it occurs even there.
  Please help me :)!</p>