The Bertha 24

This model started life as a stock Big Bertha kit, but I have a hard time building kits without modifying them. [big grin!] In this case, the original 18mm motor mount and stuffer was replaced wholesale with a 24mm mount, same length stuffer, and homemade centering rings. In addition, similarly to my last Big Bertha, scrap wood from the fin sheets was used to create additional fin strakes, though in this case they are much smaller than previously, and located further forward. Like my Cherokee-D, I've installed dual launch lugs, in order to be able to fly the rocket from either 1/8" model rocket pads, or from 3/16" pads for larger models.

 Also like my Cherokee-D, this model will be too prone to loss if flown exclusively on D and larger 24mm motors, so will often fly on 18mm motors with an adapter. The modifications have added almost no weight (only the weight of the adapter itself, and the weight difference between 8 inches of BT-50 and the same length of BT-20) -- with the result that this model will, in theory, be able to fly on motors ranging from A through E. I'll likely also install one of the 19.5" nylon x-form parachutes I purchased recently from American Science and Surplus -- anything that will deploy from a BT-56 should be a piece of cake to pack into a BT-60. 

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