Improperly printed last layers

[user898]

Hi,

The last layer never prints correctly for this (attached) model. The model does not have any manifold errors.
Notice how their is a void under the last 3 layers where extrusion begins?

Print error

I have tried all of the following and more:

[*] 100% infill
[*] 30 perimeter shells
[*] Turned off all retractions

The material is PLA. Print speed has been done at 40mm/s up to 70mm/s.

Nothing seems to fix the problem.

Here's the model:

test top.stl

STL Model

(26.84 KiB) Downloaded 65 times

Can someone please suggest how to slice this right using Simplify3D?

The model prints perfectly fine using Craftware but that software is missing some features I need which simplify3d has. Or maybe I'm just used to Simplify3D.

Thanks in advance.

[CompoundCarl]

It would probably help more if you posted your factory file (File > Save Factory File)