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Mista Ballista is Team Tormentum's Torsion Division competition catapult. We started construction in 2000 with our first purchase of two very large steel donuts that now make up the lower scutulas. The different pages documenting Mista Ballista focus on different aspects of it's construction and do not go in chronological order. 2008 Deployment 2007 Deployment Mr. B just before launch at the 2007 Punkin Chunk. This resulted in a 582ft chunk. 2006 Deployment Mr. B getting ready to launch at the 2006 Punkin Chunk. 2800 lbs of measured tension is sitting at the trigger! That's approximately 22700 foot pounds at the base of the arm, and perhaps 26800 foot pounds at the point where we had a catastrophic failure last year. To put in that tension, we had about 7000 lbs exerted by the hydraulic ram which was running around 800psi at the pump. Sproing! 670 feet! Thanks to Jim Goodwin for these two great pictures. 2005 Deployment First competition launch at the 2005 Chunk! Ouch! Things didn't go so well for us. 2004 Deployment Preparing for a test launch at the 2004 Chunk! Sproing! 2003 Deployment Preparing for a launch at the 2003 Chunk. Fire! It goes 250 feet 2002 Deployment After winding rope bundles late into the night Thursday before the 2002 Punkin Chunk, we packed up, traveled to Delaware, assembled and fired Mista Ballista for the first time. Our first shots broke pumpkins, but they did go forward about 100 feet with minimal tightening of our rope bundles. Additional Pages for Mista Ballista Mista Ballista (This Page) Mista Ballista is _Team Tormentum's_ *Torsion Division* competition catapult. Mista Ballista : Modiolus and Epizygis The Modiolus and Epizygis used in Mista Ballista account for a majority of the time spent. The size and detail needed to construct these items in a way that could reliably contain the force of so much rope worried us, and we over engineered them. Mista Ballista : Rope Bundles The rope bundles are the main engine of the machine. The framework that holds everything together is about 24 ft long, and 6 feet tall. Mista Ballista : 2005 Rope bundle Upgrade At the 2004 chunk the main stanchions for the torsion frames were bent by the impact of the arms. You can see the animation of when this happened on the Mista Ballista Arms page. Mista Ballista : 2006 Rope Bundle Reconfiguration In 2005 we broke our fancy fiberglass arms. In 2006 we got the new carbon fiber arms and video taped them in action in the summer at our 2006 History Chunk. This led us to discover how much they bounced around the outer stanchions. We were getting multiple recoils after every shot, sometimes back at least 30 degrees. That was also just with 2000 lbs of pullback, which is much less than we expect to use in competition. Mista Ballista : Frame The framework for the Ballista had to be built strong enough to resist the pullback, and to hold up the 2500 pounds we currently estimate of our engine. It must also push it up 16 feet in the air! Mista Ballista : Arms Building an arm for a torsion machine this large has been very challenging. A list of our failures in this area might provide some hints on what not to do. Mista Ballista : Trailer One of our goals for the 2003 season is to acquire a dedicated trailer for Mista Ballista. Mista Ballista : Mystery Parts All winter during 2003 we have been collecting the parts we need to accomplish our 2003 chunk goals. Here are a bunch of pictures of these random parts. Can you guess what they are for? Mista Ballista : Deployment To travel to different chunkin' locations, we need to pack the system down onto our trailer. Deploying from the folded up position is challenging and time consuming, taking a day and a half at the 2002 chunk. This year at the 2003 Punkin Chunk, we were done in about 4 hours. Mista Ballista : Torsion Mista Ballista's engine operates with torsion from twisted rope bundles. One of the biggest challenges of torsion for this machine has been adding the twist. An onager is pretty straight forward in that a large lever and gravity can be used. With our ballista, the direction of twist is sideways, so alternate means of twisting is needed. Mista Ballista : Hydraulic and Electric Power Mista Ballista uses hydraulics for lifting the engine to a 45 degree angle for firing, and also for winding the cord bundles. We also like having electricity on hand since Mr. B has a tendency to break, and need on-field repairs. This page describes what we are using to power up the system. Mista Ballista : Failed Arms Building an arm for a torsion machine this large has proven to be very challenging. Based on the experiences of our competitors, who also keep breaking arms, we find that we are not alone in this dilemma.

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Contact: Team Tormentum Copyright © 2000-THISYEAR Eric M. Ludlam All rights reserved. Twas' brillig, and the slithy toves did gyre and gimble in the wabe...

Last Modified: 11/19/08