20455 - Hemisphere 9 x 4 x 7 (from Jurassic World)

[Gerald Lasser]

The first round part of the sphere I did with Pathtruder, however I wanted to try the CSG with LDPE to get a proper result.

I want to list the steps here, first of all the final result of the CSG operations:
   
I made the blind stud transparent to show the pocket that is there.

To start we need some Hi-Res spheres, i.e. 48 divisions of a circle, for the outer and inner surfaces.

Code:

0 !LPE CSG_QUALITY 48
0 !LPE CSG_ELLIPSOID OuterSphere  16 0 68 0 85 0 0 0 85 0 0 0 85
0 !LPE CSG_ELLIPSOID InnerSphere  16 0 68 0 82.50 0 0 0 82.50 0 0 0 82.50

Now we need the inner parts, which are all formed from cylinders. Those are the bases for the Axleholes and the blind stud as I call it for a lack of better name. I have decided not to use hi-res here so switch back to 16 sides:

Code:

0 !LPE CSG_QUALITY 16
0 !LPE CSG_CYLINDER  AxleHoleR  16 50 18 0 0 25 0 0 0 9 9 0 0
0 !LPE CSG_CYLINDER  AxleHoleL  16 50 118 0 0 25 0 0 0 9 9 0 0
0 !LPE CSG_CYLINDER  BlindStud  47 50 18 20 0 20 0 0 0 9 9 0 0

Now we need the 3mm wide hole for the bases and a slightly larger cylinder to get the pocket within the Blind Stud

Code:

0 !LPE CSG_CYLINDER  HoleR    16 50 18 0 0 25 0 0 0 4 4 0 0
0 !LPE CSG_CYLINDER  HoleL    16 50 118 0 0 25 0 0 0 4 4 0 0
0 !LPE CSG_CYLINDER  PocketR  16 55 18 20 0 25 0 0 0 5 5 0 0

The final parts are used to cut the bowl into shape:

Code:

0 !LPE CSG_CUBOID    Cube  16 90 68 0 90 0 0 0 90 0 0 0 90
0 !LPE CSG_CUBOID    l  16 90 98 0 90 0 0 0 90 0 0 0 90
0 !LPE CSG_CUBOID    m  16 90 38 0 90 0 0 0 90 0 0 0 90

All parts are now available and the construction starts!
The first step is to unite the inner parts and cut the pocket. I tried to cut the pocket in the end, but this did not form the bottom of the pocket, so I did it at this step as well:

Code:

0 !LPE CSG_UNION AxleHoleR AxleHoleL InnerParts
0 !LPE CSG_UNION InnerParts BlindStud InnerParts
0 !LPE CSG_DIFFERENCE InnerParts PocketR InnerParts

   

Second Step is to cut the inner parts with the shape of the Inner Sphere as they need to be attached to this surface:

Code:

0 !LPE CSG_INTERSECTION InnerParts InnerSphere InnerParts

   

As the inner parts are nearly done, I can do the bowl itself: First cut the sphere in half, the subtract the inner sphere

Code:

0 !LPE CSG_INTERSECTION OuterSphere Cube OuterSphereHalf
0 !LPE CSG_DIFFERENCE OuterSphereHalf InnerSphere BowlHalf

   

Next we put in the Inner Parts into the bowl:

Code:

0 // Add the Inner Parts
0 !LPE CSG_UNION BowlHalf InnerParts Bowl1
0 // “Drill” the holes, the Pocket needs to be done again
0 !LPE CSG_DIFFERENCE BowlHalf HoleR BowlHalf
0 !LPE CSG_DIFFERENCE BowlHalf HoleL BowlHalf
0 !LPE CSG_DIFFERENCE BowlHalf PocketR BowlHalf

   

Finally we need to cut off the unwanted parts and we get the final result before adding primitives.

Code:

0 // Cut off the Top and Bottom of the bowl
0 !LPE CSG_INTERSECTION BowlHalf l BowlHalf
0 !LPE CSG_INTERSECTION BowlHalf m BowlHalf

Kudos to Nils for this fine SW that made the generation of this central subpart very smooth!