MX-570 / JB-3 Tiamat Two-Stage Scale Model Rocket

cults3d

I can finally update this and say that this has been tested and is stable (at least version with plywood booster fins). This was my most extensive scale build yet -- multiple prototypes were built, revised, and latest version looks really great. I have simulated this as best I can with Open Rocket. Here is the launch of this two stage rocket with a D12-0 in booster and a C6-5 in Sustainer: https://youtube.com/shorts/agvUiuc7cS8 The JB-3 Tiamat “Jet-Bomb”, also designated MX-570, was an early air-to-air missile developed by Hughes Aircraft for the United States Army Air Forces during World War II. This was the first research sounding rocket launched from Wallops Island (July 4, 1945). I decided to create the clustered-booster 3-fin version of this rocket since it is the most unique. There are some discrepancies between the original photos of the rocket that was launched and the photos of the model on display at Wallops. I have included both versions - one with sharper / deeper angles between the booster tubes / pods that matches the launched prototype photos and another with softer / shallower lines that is closer to the Wallops model on display. I also included an earlier version of the booster that was smaller. It does not match the scale drawings as well but still looks nice and may require less nose weight since it is lighter (the picture of two boosters shows the comparison of these models). Model is 19.25" / 49cm long. I provided a picture next to a Big Bertha for size comparison. Due to the complexity of the lines of this rocket, this is nearly entirely 3D printed. The sustainer is slotted for plywood/balsa fins and the booster includes a version with integrated airfoil 3D printed fins as well as slotted for plywood/balsa (I have not tested the beveled / airfoiled 3D printed booster fin version). This rocket has an 18mm motor mount in the sustainer and the booster has a canted 6x 13mm mini engine cluster around a single 24mm mount in center. You can launch with just D or E 24mm engine in booster and/or add 3 or 6 plugged 13mm engines in the cluster (I have only tested with D12 in booster). It is setup for a BT-50 motor tube in the booster so the center engine ignites the sustainer. In my simulation it seemed that this was close to stable with 3oz of weight in nose and a D12-0 in Booster (somewhat slow off the rod but with more engines you need more nose weight). 3oz is a great deal of weight for a model this size so be cautious with recovery systems and everything else if you plan to launch this model. I have included screen captures of my simulation and will provide OpenRocket ORK file with your download. I have included pictures of latest version of built model, some of the 3D designs, one of the OpenRocket Simulation, and some of the original sounding rocket as well as a model at Wallops. Disclaimer: Model rocket launching requires adult supervision and rocketeers should adhere to NAR safety regulations and federal, state, and local laws. I take no responsibility if you decide to use these components to make and launch a model rocket. These are only some of the components and final build decisions and quality is up to the experienced model rocket builders. You should always simulate and swing test your final builds to be sure they are stable.