Re: Estimating Tracker Bar Tubing Needed

OK, John, here's my solution:

1. Measure the shortest piece of tubing needed (I'd think a string
would give the best results); call this length S.

2. Measure the longest piece needed; call this L.

3. The average length needed would be (S + L) / 2

4. Total for 88 notes would be the average length times 88, or
((S + L) / 2) x 88, or simplifying, (S + L) x 44.

Actually, this gives a result that is about 6 to 8 percent too large,
since the tubes part way out from the center of the action aren't much
longer than the shortest tubes.  The difference in length from note to
note is more pronounced at the extreme ends of the action.  But it's
better to have too much tubing on hand than to come up short.

If you have an action like the Amphion where the tubes run to valve
blocks on three different decks, measure the S and L values to the
center deck.  That way there are as many pieces that need to be longer
to reach the bottom deck as there are pieces that need to be shorter,
for the top deck, and they all average out.

I just replaced the tubing recently on this Amphion, and I figured that
I would need a little more than 200 feet, using this formula.  I had
two 100-foot rolls of tubing, and when finished, had about 15 feet left
over.

Bill Luecht
bill.luecht@aes.com