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.
Baby ballista is preparing to fire one of its favorite projectiles,
an empty soda can. It is 30 inches wide, 3.5 feet long, with 1
foot long cord bundles that are 1.25 inches thick.
The arms are 16 inches long.
Baby Ballista uses a `traditional' frame set up. By traditional, I
mean the most common form found in The Book of the Crossbow.
The bowstring is a bit of doubled up clothes hanging line that was
lying about in my basement.
The arms are made of two different woods. One arm is made of walnut, the
other is made from cherry. They were left over bits from a group
furniture wood shop Roger scrounged up.
The Modiolus, which is the round bit of plywood in this picture,
was a bit of left overs from a different project. The Epizygis is
a 1/2 inch partially threaded bolt resting across the top, and was
left over from a bulk purchase for a different project.
The cord bundle is made from 1/4 inch braided nylon, a 3 dollar
purchase.
Our trigger is based on a spear throwing ballista trigger, instead
of the rock ballista we are actually building. Internet stories
about a blocked hook design made us shy away from building one of
those on a large scale, so we used the wheel design in our
model.
The extra bit of line on the bowstring was due to a
miscalculation on the length of our runway, but proved useful
while playing with rock pouch designs.
A shot of the trigger wheel partially turned over. You can see
another trigger similar to this one on Juggernaut2. It is the second
to last image on the page.
During a day of flinging with Onager Jr. a couple kids got to play
with our model ballista. Here is one of them setting up an empty
cranberry jug for a toss.
Here they are launching an empty 20oz soda bottle. it launched them
about 20 feet or so. It could have done better, but the high wind
resistance, and low weight of the bottles cause them to stall early.
Visit the 2001 History Channel Chunk where
there is a little more on Baby Ballista.
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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