I do not know td , I think the best solution is:
- create the tube;
- on a tangent plane the outer surface of the tube, with an angle of 45° create the first passing hole;
- create a circular set of the newly created hole, using the 45° series angle with 3 copies.
I attach the result to the above mentioned solution.
with pro|e instead everything is even easier because you can create the first hole in any position and passing only on the first wall (in practice that does not cross all geometry), you create a circular series of 8 copies for 45°, you exclude the holes that we do not want to be placed, and the game is made... :smile: