There is the "Rings and Cones" which can be found in the "Tools" Menu of LDPE, that gives the following result:
1 16 0 0 0 1.16666666 0 0 0 -1 0 0 0 1.16666666 4-4rin66.dat
1 16 0 0 0 1.28142076 0 0 0 -1 0 0 0 1.28142076 4-4rin61.dat
1 16 0 0 0 1.30242766 0 0 0 -1 0 0 0 1.30242766 4-4rin61.dat
On the other hand, what if you extend the outer cylinder by 0.25 LDU (0,1mm) ? it wouldn't fit?
1 16 0 0 0 1.16666666 0 0 0 -1 0 0 0 1.16666666 4-4rin66.dat
1 16 0 0 0 1.28142076 0 0 0 -1 0 0 0 1.28142076 4-4rin61.dat
1 16 0 0 0 1.30242766 0 0 0 -1 0 0 0 1.30242766 4-4rin61.dat
On the other hand, what if you extend the outer cylinder by 0.25 LDU (0,1mm) ? it wouldn't fit?