Tubulum Construction: How does including elbows affect the pitch?

Question

I am considering building a tubulum out of 2" PVC pipes. (Like Blue Man Group) There are some specs on the internet for making the notes, but no one really says when inserting an elbow into the length, how much doing it will change the pitch of the note. Can I add a fixed amount to the overall pipe length for each elbow? I would like to know ahead of time before I do a lot of cutting and wasting time and materials. I would think it would be better to have at least one bend in each pipe because you want to strike the pipe in a vertical position, but you want the end to be in a somewhat horizontal position facing the listeners.

I am especially interested in the guidance of someone who has first hand experience in building a tubulum.

Answer 1

As a rule of thumb, you can measure the length of the elbow along a line through its middle and add it to the whole. I would still (as I did with my tubulum) make the total length of each pipe a few inches longer than the specs and tune to pitch when it's done anyway.