I don't know why you used the box4t and this quad for the outside
1 16 0 30 0 15 0 0 0 -30 0 0 0 15 box4t.dat
4 16 -15 30 -15 -15 0 -15 15 0 -15 15 30 -15
Shorten the stud4:
1 16 0 4 0 1 0 0 0 -6.5 0 0 0 1 stud4a.dat
You can't use a box5 for the inside, so instead of:
0 BFC INVERTNEXT
1 16 0 30 0 12 0 0 0 -26 0 0 0 12 box5.dat
use:
0 BFC INVERTNEXT
1 16 0 30 0 12 0 0 0 -26 0 0 0 12 box4.dat
1 16 0 4 0 8 0 0 0 -1 0 0 0 8 4-4ndis.dat
4 16 -12 4 -12 -12 4 12 -8 4 8 -8 4 -8
4 16 -12 4 -12 -8 4 -8 8 4 -8 12 4 -12
4 16 12 4 -12 8 4 -8 8 4 8 12 4 12
4 16 -12 4 12 12 4 12 8 4 8 -8 4 8
The outer box instead of:
1 16 0 30 0 15 0 0 0 -30 0 0 0 15 box4t.dat
construct it like this:
1 16 0 30 0 15 0 0 0 -30 0 0 0 15 box4.dat
1 16 0 0 0 6 0 0 0 1 0 0 0 6 4-4ndis.dat
4 16 -6 0 6 6 0 6 15 0 15 -15 0 15
4 16 -6 0 6 -15 0 15 -15 0 -15 -6 0 -6
4 16 -6 0 -6 -15 0 -15 15 0 -15 6 0 -6
4 16 6 0 -6 15 0 -15 15 0 15 6 0 6
Now the top stud2 needs to get rid of the inner edge lines, replace:
1 16 0 0 0 1 0 0 0 1 0 0 0 1 stud2.dat
with:
1 16 0 0 0 1 0 0 0 1 0 0 0 1 stud2.dat
1 16 0 0 0 6 0 0 0 1 0 0 0 6 4-4edge.dat
and extend the hole to the stud4 with:
0 BFC INVERTNEXT
1 16 0 0 0 4 0 0 0 4 0 0 0 4 4-4cyli.dat
1 16 0 4 0 4 0 0 0 1 0 0 0 4 4-4edge.dat
1 16 0 4 0 2 0 0 0 -1 0 0 0 2 4-4ring2.dat
Hope that helps
1 16 0 30 0 15 0 0 0 -30 0 0 0 15 box4t.dat
4 16 -15 30 -15 -15 0 -15 15 0 -15 15 30 -15
Shorten the stud4:
1 16 0 4 0 1 0 0 0 -6.5 0 0 0 1 stud4a.dat
You can't use a box5 for the inside, so instead of:
0 BFC INVERTNEXT
1 16 0 30 0 12 0 0 0 -26 0 0 0 12 box5.dat
use:
0 BFC INVERTNEXT
1 16 0 30 0 12 0 0 0 -26 0 0 0 12 box4.dat
1 16 0 4 0 8 0 0 0 -1 0 0 0 8 4-4ndis.dat
4 16 -12 4 -12 -12 4 12 -8 4 8 -8 4 -8
4 16 -12 4 -12 -8 4 -8 8 4 -8 12 4 -12
4 16 12 4 -12 8 4 -8 8 4 8 12 4 12
4 16 -12 4 12 12 4 12 8 4 8 -8 4 8
The outer box instead of:
1 16 0 30 0 15 0 0 0 -30 0 0 0 15 box4t.dat
construct it like this:
1 16 0 30 0 15 0 0 0 -30 0 0 0 15 box4.dat
1 16 0 0 0 6 0 0 0 1 0 0 0 6 4-4ndis.dat
4 16 -6 0 6 6 0 6 15 0 15 -15 0 15
4 16 -6 0 6 -15 0 15 -15 0 -15 -6 0 -6
4 16 -6 0 -6 -15 0 -15 15 0 -15 6 0 -6
4 16 6 0 -6 15 0 -15 15 0 15 6 0 6
Now the top stud2 needs to get rid of the inner edge lines, replace:
1 16 0 0 0 1 0 0 0 1 0 0 0 1 stud2.dat
with:
1 16 0 0 0 1 0 0 0 1 0 0 0 1 stud2.dat
1 16 0 0 0 6 0 0 0 1 0 0 0 6 4-4edge.dat
and extend the hole to the stud4 with:
0 BFC INVERTNEXT
1 16 0 0 0 4 0 0 0 4 0 0 0 4 4-4cyli.dat
1 16 0 4 0 4 0 0 0 1 0 0 0 4 4-4edge.dat
1 16 0 4 0 2 0 0 0 -1 0 0 0 2 4-4ring2.dat
Hope that helps