Generative Algorithms - Porous Structures

hi,

i try to explore for me the tutorial "POROUS SHELL" by zubin m khabazi.
http://www.grasshopper3d.com/page/tutorials-1

Unfortunately I have overlooked something in phase three,
and the result is not gratifying.
maybe someone has also made this tutorial,
and can draw attention to my fault.

that would be very nice.

as you can see, the edge MidPts and some circles are not created!

 

this must be like the picture above.