After Mista Ballista had a arm failure on it's second year out at the 2003 Punkin Chunk,
we decided to use Baby Ballista as a test platform for a new and lighter bowstring
attempt. We took our basic design from The Book of the Crossbow and enhanced it
based on the materials we hoped to use on the big guy.
First Amy made a throwing pouch that would fit a cherry tomato. This would be similar
in design to the pouch made for the big ballista, but we are not planning on building
a rigid frame for it this time.
The tomato was chosen as being small scale equivalent to a pumpkin.
After experiments with string Roger then learned how to splice multi-strand braided rope
which is what all the high tech super strong ropes are made as. We measured two lengths
of this small yellow braided polypropylene to fit a new set of arms for the ballista
and spliced eyes onto each end.
Mista Ballista's arms have pegs on the end which we loop the bowstring onto. The new arms
for our little ballista mimic this feature.
Next, a throwing pouch was woven into the line. Historically, the bowstring would be
several parallel strands, and the pouch would be tied on by winding another rope around
the bowstring over and over. With the braided rope, we opted to splice the string
tying on the pouch into the bowstring.
And naturally, we had to go outside and shoot some cherry tomatoes with it. To our amazement we were unable to measure their distance because they went completely over
the cul-de-sac (160ft) up a hill (+40 ft) and flew over Roger's head at the edge of
a property we didn't want to tromp around in late at night with a powerful flashlight
(+30ft). They seemed to have flown over 230 ft. Except for the ones that got blasted
into small fragments upon launch.
As the ballista used to shoot soda bottles about 30 or 40ft, this was an impressive
improvement.
We used a small sea-catch Eric had purchased for building a competition catapult
to be used by his children an upcoming year. It's 700lb working load was a bit of
overkill for this operation, but we didn't mind.
We performed our launches from the top of a big trash can. A convenient height to
operate on a night with temperatures hovering around 21 degrees F.
Additional Pages for Baby Ballista
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Baby Ballista
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Baby Ballista was constructed while we were trying to design Ballista
Jr. We had realized part way through that we weren't quite sure what
was up, so we built Baby Ballista in an attempt to figure our what was
going on.
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Bowstring Upgrade
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After Mista Ballista had a arm failure on it's second year out at the 2003 Punkin Chunk,
we decided to use Baby Ballista as a test platform for a new and lighter bowstring
attempt. We took our basic design from _The Book of the Crossbow_ and enhanced it
based on the materials we hoped to use on the big guy.
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Test Firing
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In June 2005 my brother Greg came out from California, and we spent time shooting
the catapults. I recorded the results for Baby Ballista.
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