Mista Ballista returned to Delaware to compete in the Torsion division once again.
It was a competition fraught with challenges.
Mista Ballista left Massachusetts at 11:30 pm, and drove straight through the night
and onto the chunkin' field in Millsboro Delaware at 8:00 am. Here the trailer
had just been detached, and Jeff pulls out a drill to finish a task that had been
left undone from MA.
The only other team on the field was Fibonacci way down at the far end of the
catapult line. And no wonder. It was beginning to rain as Roger covers up the
equipment.
Despite the rain, the team continued on. Here Jeff begins deploying the rope
bundles from the horizontal to vertical position. This is done by using a come-along
on the front end of the ballista rope bundles. You can read more about
Deployment here.
That night, Roger worked into the wee hours of the morning attempting to splice
our new bowline together with the pouch from the previous year. The bowstring is
a high tech 6mm 12 strand braid. Roger was able to splice it together with a home-made
splicing tool made from a copper pipe and some solder. Nifty.
We worked feverishly attempting to get ready for our first shot at 8:30am on
Friday, but missed the deadline. Instead we concentrated on making sure we
didn't break any of our expensive parts. Here leather is wrapped around the
new fiberglass arms we made. The leather is meant to protect the torsion bundle
from the sharp edges left behind by the lightweight resin filler we used
to remove the bigger rough edges from bagging the arms in the first place.
Learn more about the
arms here.
Next, we installed the new arms into the rope bundles. Eric and Dave manage the
torsioning of the upper modiolus, Jeff handles the lower, and Roger makes sure
nothing falls down.
Our new torsioning arms made this much easier. We got them much tighter by just
pushing on these arms. Later, a come-along tightened them up even more. At the
very end (on Sunday) we pulled out the hydraulic cylinders to put the final bit of
wind into them.
At long last, we get to test the new bowstring Roger had worked so hard on.
Here you can see our fancy new snatch block we built. Roger had forgotten the
one we usually use, so we had to fabricate our own out of a spare pulley and scrap steel.
As the rope pulled back, eventually, one of Roger's splices came undone, and shot
the pumpkin out of the ballista about 200 feet into the field. That was the end
of our Friday adventures.
Bright and early the next morning, the torsion bundles were tightened and
this Australian Blue Pumpkin was fit into the pouch. A pouch Roger once
again worked late into the night repairing. We had warned one of the spotters
about these particularly ugly pumpkins, and he recognized it when we shot it
at him. Unfortunately, a bowstring splice once again slipped during pullback,
but we had pulled back far enough, and tightened things up, so our shot went
off 358.73 feet. This secured our 3rd place position in the Torsion division.
This just helped prove that all the work we put into these new fiberglass arms
and lightweight bowstring is really paying off. This improved distance was at
half the wind strength of last years best shot.
Roger spent the rest of the morning hunting down someone who knew how to splice
this type of rope to avoid a third splice failure on Sunday. Once the secret was
revealed (ie, no one had tried making a ballista bowstring before) we just made
something up, and off he went.
Eventually Eric's son Trevor showed up, and got to play on the catapult.
He liked all the catapults, but seemed more interested in all the carnival
rides.
Later that day, disaster strikes. Team Chucky apparently was scared by our
show of force that morning, and lobs a pumpkin straight up a few hundred feet
and on to our torsioning system we
were preparing to use. It left a massive amount of pumpkin mess on the deck
of the trailer and all over our hydraulic cylinders. Mark donated many
paper towels as we tried to clean up the pumpkin guts.
That night, the bowstring layout is tested again. One of the splices was misplaced
and Roger had to remove it and try again. Getting everything even was really challenging
on this project. An uneven location, and one line will take more force than the other
and increases it's chance of failure. An uneven line could also cause the ammunition
to miss the opening on the front of the machine and smack into the regulae.
We showed up Sunday morning even earlier than usual to test out the new bowstring.
To everyone's relief, it holds! Huzzah!
Which of course meant it was time to pull out the hydraulic cylinders and put some
real tension into our rope bundles. Hoo-ya! The new torsioning arms proved to be
very safe, and all four ends were give a 1/4 turn for good measure.
We pulled the system back with an Orange pumpkin. The last Blue was sent to
the Pumpkin Putter for use on its last shot.
The bowstring held to the last. As Eric tugged at the Seacatch lanyard, however,
it did not release right away, and the pumpkin slowly started to fall out of the
pouch. When it finally launched, the orange pumpkin was sent on it's way but a small
section was scalped off the bottom, thus disqualifying our shot. There was so much
power in the launch that the lower bowstring sliced the bottom very cleanly off the
pumpkin. The scalp was left on the deck of our trailer. We are guessing the shot
went about 500ft.
Unfortunately, during this chunk, we also bent our stanchions. You can examine
the animation of this in the Animation section below.
After fixing the decapitation problem, we spent the rest of the day slinging gourds.
We were able to launch a new pumpkin about every 5 minutes.
Sproing! Off it goes! Too bad our lower right bowline bushing decided to go
sailing off. This was our last shot.
Another view from below the raised rope bundles.
And then the 3rd place trophy was ours! Huzzah!
Move mouse over a frame number to switch to a different frame view.
In this animation you can see the bowstring slinging the pumpkin. Then in frame 3
the stanchions bend, and the pumpkin is pulverized. In frame 6, the remaining bits
of pumpkin are sent skyward.
Google Video Service
Mista Ballista 2004
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Information:
Shot sunday afternoon after the Punkin Chunkin copetition was over. 28 sec - Jun 25, 2006
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Additional Pages for Punkin Chunk 2004
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Punkin Chunk 2004
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The 2004 World Championship Punkin Chunk was a great year for Team Tormentum.
We brought Mista Ballista, our torsion machine.
We also brought the Pumpkin Putter out of retirement to compete in the
the new Human Powered Centripetal division.
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Punkin Chunk 2004: Mista Ballista's Story
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Mista Ballista returned to Delaware to compete in the Torsion division once again.
It was a competition fraught with challenges.
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Punkin Chunk 2004: The Torsion Division
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The torsion division returned for more adventures this year. While the outcome
as the same as last year, the adventures were all different.
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Punkin Chunk 2004: Pumpkin Putter's Story
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The Pumpkin Putter returns from retirement to defend its previously unofficial title
as champion human-powered centripetal. Don Young was instrumental in getting this
new division together.
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Punkin Chunk 2004: The Human Powered Centripetal Division
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The Centripetal division was very tightly matched. While the other
machines had trigger problems, when they did work, they all sent the
pumpkin out past 100 feet.
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Punkin Chunk 2004: Other catapult divisions
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Battles raged in the youth and trebuchet divisions, and a new record was set in the
unlimited catapult division.
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