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.

We discussed many possibilities, and it was decided that we could leave the stanchions bent (which gave us more room for arms) and just reinforce them.

We had to fully disassemble the machine to accomplish this.

First things first, we had to remove some welds we had made that held the epizygii in place. We could then remove the epizygii and pull the rope out.

Once things were removed from one side, the entire rope bundle could be extracted out the back side.

Next up, remove the engine frame from the trailer. Dave got to use his forklift with exciting effect to manage this maneuver. The bundles are certainly on the edge of the forklift's capacity.

This picture shows quite clearly the amount of bending the stanchions have gone through.

Once it was down, it was time to start cutting, fitting, and welding steel plates onto all four of the bent stanchions. We had found several pieces of 1/2" steel plate that were just the right size to be split and added over the bent stanchion. This process took several weeks. (We meet once a week Thursday evening.)

Each time one side was partially welded or painted, Dave brought out the forklift and flipped the frame over to access the other side.

Eventually, all the welding was complete, and we even got the frame painted up. Huzzah!

Dave had purchased two new 600ft spools of 1" nylon rope to replace the yellow poly-propylene.

Eric greases up the modiolus in preparation for rewinding the bundle.

Roger and Eric lay the first layer of rope in without pulling the entire spool through. Each strand we pull through and make as tight as possible.

To speed up winding, the massive spool is layered up, and tied together so we only need to pull 120ft through at a time, instead of 500 ft.

We continue on deep into the night, filling up the bundle until there was no room left. We managed to stuff about 500ft of rope in. See the 2005 Punkin Chunk for more on how these bundles performed.

Additional Pages
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 (This Page)	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.