An idea on Moineau pumps

I needed a pump for a viscous fluid in one of my projects and it seemed a no brainer to uses ttsalo's version http://www.thingiverse.com/thing:15538

However, I have been hitting a wall in my tests and when discussing the matter it was pointed out that stator should be made of rubber to provide a tight fit with the rotor so cavities are sealed while moving.

Not having elastic filament at hand nor experience on how rubbery it might be, I asked around. User A2 suggested on reprap forums http: