RACER SHAPE, was RE: [Balloon-makers] Singer Oiling and Gremlins

[Don Piccard]

Nightmares...
Well, Sandy, the idea of building a racer is great.  But the idea of copying
one on the market is fraught with pitfalls.  There is a lot that may not
meet the eye.  There are hidden things.  One I think of is the ratio of skin
tension versus load tape tension in the sewing process which would be
critical for the stress analysis.  I have seen that one completely missed by
the rip off artists.

Please be very careful and verify your design details by your own
engineering not just by assuming what you see is what you get.  I have very
disturbed by observing close copies that overlooked seemingly minor, but
actually very critical, points.

Yes, the carnival smoke balloon barnstormers would grab some muslin and sew
a "Lock seam" to make a racer shape balloon that could lurch into the sky
hundreds of pounds light, but they used heavy muslin and wore their bags out
in just a few hors or maybe minutes of flight time.  A tall thin balloon
gets a lot more stress than a Natural Shape unit.

Your high school geometry student, especially one with a CAD program, should
be able to help you with the volume.

Good fortune, and fly safely,

Don  Piccard

-----Original Message-----
From: balloon-makers-bounces at taleos.com
[mailto:balloon-makers-bounces at taleos.com] On Behalf Of Sandy
Sent: Thursday, August 09, 2007 7:13 AM
To: Norm Best; Paul Vincent Craven; balloon-makers at taleos.com
Subject: Re: [Balloon-makers] Singer Oiling and Gremlins

Daydreams...
I'd like to build a racer type balloon next spring when I get my garage back

after Jeff's project is moved to a hanger.  While I can build one simply, 
well alot of calculations, by copying one on the market, I am mathamatically

challenged to calculate the volume.  Does anyone have a program similar to 
the Smalley spreadsheet?
Any thoughts on "racer" type balloons.

Sandy Hixenbaugh-Barlett



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