I'll try to be as polite as possible but I don't understand what you are trying to accomplish,
and I don't have the part, nor can I find any images of it.
In your part 13.dat
The light blue inner surface is not allowed to touch the outside salmon surface
4 9 15 11.5 -17 15 -7 -17 15 -7 1.25 15 11.5 1.25
4 9 12.5 -10 -1.89 -12.5 -10 -1.89 -12.5 -10 1.25 12.5 -10 1.25
4 9 15 -7 1.25 15 -7 -1.89 12.5 -10 -1.89 12.5 -10 1.25
4 12 10 -7 1.25 10 -11 1.25 13 -11 1.25 16.5 -7 1.25
4 12 10 11.5 1.25 10 -7 1.25 16.5 -7 1.25 16.5 11.5 1.25
What is the point of having a ring prim inside this ndis?
1 5 0 -21 1.25 1 0 0 0 0 1 0 -1 0 2-4ring3.dat
1 10 0 -21 1.25 4 0 0 0 0 4 0 -1 0 2-4ndis.dat
Better to use a smaller ndis and add two quads on the sides.
When placing quads around a ndis you should connect them to the corners of the primitive.
1 13 0 0 1.25 10 0 0 0 0 -10 0 -1 0 2-4ndis.dat
3 14 -10 -10 1.25 -16.5 -7 1.25 -13 -11 1.25
4 14 -16.5 11.5 1.25 -16.5 -7 1.25 -10 -10 1.25 -10 11.5 1.25
4 14 -10 -10 1.25 -13 -11 1.25 10 -11 1.25 10 -10 1.25
Why do you place a big quad above this cylinder
4 4 12.5 -10 -17 -12.5 -10 -17 -12.5 -10 -13.89 12.5 -10 -13.89
0 BFC INVERTNEXT
1 10 0 0 -17 10 0 0 0 0 -10 0 3 0 2-4cyli.dat
and I don't have the part, nor can I find any images of it.
In your part 13.dat
The light blue inner surface is not allowed to touch the outside salmon surface
4 9 15 11.5 -17 15 -7 -17 15 -7 1.25 15 11.5 1.25
4 9 12.5 -10 -1.89 -12.5 -10 -1.89 -12.5 -10 1.25 12.5 -10 1.25
4 9 15 -7 1.25 15 -7 -1.89 12.5 -10 -1.89 12.5 -10 1.25
4 12 10 -7 1.25 10 -11 1.25 13 -11 1.25 16.5 -7 1.25
4 12 10 11.5 1.25 10 -7 1.25 16.5 -7 1.25 16.5 11.5 1.25
What is the point of having a ring prim inside this ndis?
1 5 0 -21 1.25 1 0 0 0 0 1 0 -1 0 2-4ring3.dat
1 10 0 -21 1.25 4 0 0 0 0 4 0 -1 0 2-4ndis.dat
Better to use a smaller ndis and add two quads on the sides.
When placing quads around a ndis you should connect them to the corners of the primitive.
1 13 0 0 1.25 10 0 0 0 0 -10 0 -1 0 2-4ndis.dat
3 14 -10 -10 1.25 -16.5 -7 1.25 -13 -11 1.25
4 14 -16.5 11.5 1.25 -16.5 -7 1.25 -10 -10 1.25 -10 11.5 1.25
4 14 -10 -10 1.25 -13 -11 1.25 10 -11 1.25 10 -10 1.25
Why do you place a big quad above this cylinder
4 4 12.5 -10 -17 -12.5 -10 -17 -12.5 -10 -13.89 12.5 -10 -13.89
0 BFC INVERTNEXT
1 10 0 0 -17 10 0 0 0 0 -10 0 3 0 2-4cyli.dat