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Most rockets |'ve seen or flown rely on a cylindrical airframe to transport all forces from the motor (thrust plate and/or internal rings or bulkheads), and take any bending forces. These vary from cardboard to fiberglass and carbon fiber tubes, but they all carry the forces in the airframe tube (skin).
I know there are large commercial rockets using internal framing, and a thin skin to provide good aerodynamic form. Some larger HPR projects use internal frames, maybe because they can't easily find large tubes that are strong and light enough. A friend was telling me of a large project several years ago that was a frame built of wooden 2x3's, and skinned with thin plywood. Would love to see the build, if anyone has a link.
I'd like to explore some simple internal framing methods on a small scale, say a 3" or 4" diameter rocket on a J or K class motor. I'm thinking of a frame of pultruded carbon fiber rods/tubes held in place by several bulkheads (and centering rings by the motor mount), and a thin (non structural) skin of plastic. Think of how some older airplanes were made using wooden stringers covered with fabric skins.
I've been experimenting with 3D printed sections where the faces of the sections get a couple of layers of fiberglass that works like a thin bulkhead, and held together with threaded steel rods, and skinned with a layer of fiberglass, but the construction is a bit heavy, mostly from the steel rods, and the fairly robust 3D printing and infill. Built like a tank. Flies well enough, though.
I'm sure there are references to internal frame construction techniques, but are hard to find here on the forum. Just looking for links or your ideas and suggestions.
I know there are large commercial rockets using internal framing, and a thin skin to provide good aerodynamic form. Some larger HPR projects use internal frames, maybe because they can't easily find large tubes that are strong and light enough. A friend was telling me of a large project several years ago that was a frame built of wooden 2x3's, and skinned with thin plywood. Would love to see the build, if anyone has a link.
I'd like to explore some simple internal framing methods on a small scale, say a 3" or 4" diameter rocket on a J or K class motor. I'm thinking of a frame of pultruded carbon fiber rods/tubes held in place by several bulkheads (and centering rings by the motor mount), and a thin (non structural) skin of plastic. Think of how some older airplanes were made using wooden stringers covered with fabric skins.
I've been experimenting with 3D printed sections where the faces of the sections get a couple of layers of fiberglass that works like a thin bulkhead, and held together with threaded steel rods, and skinned with a layer of fiberglass, but the construction is a bit heavy, mostly from the steel rods, and the fairly robust 3D printing and infill. Built like a tank. Flies well enough, though.
I'm sure there are references to internal frame construction techniques, but are hard to find here on the forum. Just looking for links or your ideas and suggestions.