The modifications cleared the end effector, but now would have intersected with the cables at the back of the build area.  Bah.

The new solution now squashes the part light ring down from a circle to an ellipse.  

I've been stuck in thinking it could only be a cylinder from the 'light intensity falls off as square of the distance' thingy, but then again, I'm also then putting more elements in the same space due to the increased circumference.  It will probably all even out.  

The diameter of the ring is all old math, and was based on even multiples of the segment length for the light strip fitting the inner circumference.  I hope that scales like I think it does.  

It may also bring the edge of the ring into the FOV of the camera, which may cause me to need to move it back closer to the camera to kill the glare.  

Trying it.

Printing.