How can I cut the back of an airfoil to constant thickness of 0.4mm?

 From:  simba 9 Nov 2014  (4 of 5) 
7023.4 In reply to 7023.3 
Hello Michael,

I cannot reproduce the creation of the fillet.

I split the shell into two parts but when I try to create the fillet as proposed, the calculation fails?!

What is it, I am missing?

S.
Attachments:
Attachmentbasefoil_V2.3dm