Have anyone attempted the Curta Calculator?

Hey guys, 

I actually got the machine specifically to try to tackle this: 


I'm new to this world, so I'm sure there is some setting that perhaps need tweaking... 

I am encountering an odd issue with the upper_housing_-_upper_housing.stl, trying with 0.4 nozzle, 0.1mm layer, 65% infill, fine quality. The raft prints ok, and it is solidly attached to the print surface, but the part itself keeps detaching itself from the raft a few layers in. 

I have tried several other prints of other not Curta parts, and those seem ok, so perhaps there is some tweaking needed for this specific geometry.

It is a 40hr+ print, so any guidance that would speed my trial and error would be most appreciated.