Parametric Motion Isolation Nut

So, to be honest, this is not really meant to be used. It is based on some discussion in #reprap around isolating a leadscrew motion from the carriage.

They pointed to this totally overkill product:
http://punk-couplings.co.uk/products/punk-nut/

And of course it just had to be modelled.

Very tiny clearances should allow it to be printed in one piece, and it should take any standard M8 leadscrew nut.

Totally not tested.