This demure craft is a mere 7.5 in diameter and over 9 feet tall! The business end sports a 98 mm motor mount. The OMH Bertha flies on Full Ms or (N motor preferred) and is reaches altitudes around 8,000 feet to 12,000 feet respectively. He will be lofting this bird into the sky on Thursday during the Tripoli Research Launch portion of HellFire on a motor he built.
The rocket is especially unique in it's construction. Most of the rocket is actually screwed together rather than epoxied together. This is for a couple of reasons, first, Tim is hyper-sensitive to epoxies so he can't be around them, secondly, the Bertha's fin design is notorious for breaking one when it lands. So, Tim built the fins so that they bolt on and off. Smart.
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The rocket has been painted to the original Estes Bertha kit K-23 paint scheme. It is a self design-construction.
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Tim didn't get a chance to fly this beast at HellFire 12 but he made up for it at Balls 15 in 2006. Just like a real Big Bertha, one of the fins broke upon landing. Tim's design allows for very easy replacement of the fins. The rocket flew ~8800 feet on an N motor that Tim built.
Project Big Bertha
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