Extrude tapered : find limit

 From:  PaQ
7917.1 
Hello guys,

Is there any trick to get tapered extrusion finding to maximum limit on simple shape like this ?



I mean, i'm trying to end with a sharp corner on the top of the extrusion, but it's really hard to archive.
(either i'm too low in the extrusion distance and I create a small plane like on the attach. example, or I'm too far and the model vanish).

(I need a quick solution to build roofs on lots of differents (but simple) houses shape)
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