Tubulongs: help!

Stevie and I stocked up on copper plumbing pipe (10 feet of 1"
diameter, and 10 feet of 3/4" diameter), and today we began cutting
them. However, we've run across a few peculiarities that have left
us quite perplexed. For one, we noticed that large diameter pipes
are higher in pitch than small diameter pipes...the ones we got seem
to differ almost uniformly by major thirds. We also noticed that
drilling holes in the pipes lowers the pitch by a small amount, and
were wondering if it matters where along the pipes the holes (for
mounting via suspension) should be drilled. Also, we tried grinding
a few down to raise the pitch but were shocked to find that grinding
actually *lowered* the pitch...this boggles me. I imagine it must
have something to do with temperature, so tomorrow I'm going to check
back and see if the pipes have changed pitch over night.

All complications aside, we were actually quite fortunate in that out
of 6 random sample pipes we cut, 3 were actually perfectly in tune
with our chosen scale, and 2 more were very close (within 15 cents).
Tomorrow we'll hopefully get at least half of the tubes cut.

We'd appreciate any advice for fine-tuning these things, or
suggestions on how to suspend them.

BTW, we did a lot of work on the keyboard ideas too, but I've decided
I've taken up enough of the group's time with that topic so I'm going
to start a blog to document our progress. If anyone's interested,
I'll post a link once I get it going.

-Igs

Hi IJ!
I thought i had mentioned the phenomenon of diameter before with the incresed mass mainly effecting volume The more metal the more resistance hence a higher pitch. it sound like you are heating the tube up quite a bit , sounds like you are using a machine which i do not recomend. hack saw, also to take off small slivers , you can only drill small holes at the nodes being .225 of the length

Igliashon Jones wrote:

>Stevie and I stocked up on copper plumbing pipe (10 feet of 1" >diameter, and 10 feet of 3/4" diameter), and today we began cutting >them. However, we've run across a few peculiarities that have left >us quite perplexed. For one, we noticed that large diameter pipes >are higher in pitch than small diameter pipes...the ones we got seem >to differ almost uniformly by major thirds. We also noticed that >drilling holes in the pipes lowers the pitch by a small amount, and >were wondering if it matters where along the pipes the holes (for >mounting via suspension) should be drilled. Also, we tried grinding >a few down to raise the pitch but were shocked to find that grinding >actually *lowered* the pitch...this boggles me. I imagine it must >have something to do with temperature, so tomorrow I'm going to check >back and see if the pipes have changed pitch over night.
>
>All complications aside, we were actually quite fortunate in that out >of 6 random sample pipes we cut, 3 were actually perfectly in tune >with our chosen scale, and 2 more were very close (within 15 cents). >Tomorrow we'll hopefully get at least half of the tubes cut.
>
>We'd appreciate any advice for fine-tuning these things, or >suggestions on how to suspend them.
>
>BTW, we did a lot of work on the keyboard ideas too, but I've decided >I've taken up enough of the group's time with that topic so I'm going >to start a blog to document our progress. If anyone's interested, >I'll post a link once I get it going.
>
>-Igs
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> >Yahoo! Groups Links
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--
Kraig Grady
North American Embassy of Anaphoria Island <http://anaphoria.com/>
The Wandering Medicine Show
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