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World Championship Chunk 2007: Mista Ballista
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Mista Ballista returned to Delaware for the 2007 Punkin Chunk. We didn't get everything done that we wanted, but we had high-hopes to improve over last year.
We started to do the master list checking and last minute packing after work. One of the tasks involved filling tires with the correct air pressure, but the regulator on the air-compressor was broken at only 40psi and Mr. B wanted 115 psi in the tires. Getting that fixed with a regulator that happened to be around took a long time, and we didn't end up leaving till just after 11 PM.
Each time we put this Ballista together, it's a little easier and faster. This time we had to finish making our strengthened torsion arms by doing the final fit to the modiolii. The rope bundles are gettiing loose, we were able to put 270 degrees in using just the 2 ton come-along.
Today early we looked at our setup from the previous day, and it looked like the arms had drifted in. When that happens, there's a chance the arm butt will bump a frame member during pullback. See the 2005 chunk when we broke our arms due in part to this problem. So we unwound both sides (one at a time) and rewound with a little bit more twist than we started with.
When the time came to fire everything worked well, and we shot 582 feet. Our new trunnions, and the fancy electric-hydraulic valve really saved a lot of time for us. Huzzah!
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Contact: Team Tormentum Copyright © 2000-2022 Eric M. Ludlam All rights reserved. Twas' brillig, and the slithy toves did gyre and gimble in the wabe... | Last Modified: 05/10/09 |
At about 3 AM, the rear driver-side tire blew out on the highway at about 50 mph. Fortunately 
Hey, what's that cruising down the highway? Every year I try to take a picture of the ballista cruising the highway and they rarely come out well. We don't seem to travel by daylight anymore so options are limited. We left so late, however, that we drove straight through till morning and I managed to get this shot.
Once we slid the rope-bundles forward, it was time to bolt on all the support beams. We've gotten much better at this, and we were done fairly early in the morning, and were ready for winding.
While on the field, 
Next, we stuffed the arms in. The wooden structure on the bottom of this picture is the "Arm Centering Tool". It supports the arm at the center of the rope-bundles, and the metal pin that sticks straight up positions the arm so that it won't bump into the framework of the ballista.
Bolt on the torsioning arm. You can clearly see the three pins that hold the arm into the holes on the 
Test fit the back of the machine in our Ballista hole. You can see the support trailer was rained on by hydraulic fluid when a change to the valving leaked while 
Saturday started for 
We then started to torsion up the other side and after the first 30 degrees, we noted that we bent a pin in our new "stronger" torsion arm.
We swapped it out for the backup torsion arm, and sheared 1 of 3 of the 1" pins. Thankfully, the shear did not cause the bundle to completely unwind.
We then started asking around, and Wayne Wallace of team "Lets Bounce" helped us out big-time with use of an acetylene torch and welder to bend our first torsioning arm back into shape, then strengthen it. We returned and found the machine badly unbalanced, so we went for it and put in 30 more degrees of twist.
During the free-for-all, we did a full pull, and everything was fine. In this picture, 
We fired, pied the shot, and our right arm buckled in recoil, putting us out of the game for the rest of the weekend. It was a sad moment for the team as our precious arms were now trash. Pullback had measured 4000 lbs at the trigger, which equals 43,650 ft lbs of torque for both bundles combined.
Once again, the torsion class ruled the field with massively long distance shots and the usually great Torsion comraderie.
Hatra Ballista Jr took its first trip to Delaware for the '07 chunk to compete in the _Youth 10 and Under_ division. It came down on the roof of Grandpa's van, and didn't hit the field till 7:45 am on Friday.
The 10 and under catapult category had three machines in it this year, and everyone I talked to was plenty friendly. The families had a tendency to disappear after their shots, so I didn't get to chat with them much.
Various notes from other divisions, and events of interest.