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Brings the reader through Level 1, 2, and 3 of HPR. Chock-full of information and pictures about building rockets at the HPR scale.
Topics in Advanced Model Rocketry
Materials
MMPDS Metallic Material Properties Development and Standardization by Battelle Institute and the FAA
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Focuses on the manufacturing of all kinds of composites. There's all sorts of cool stuff about various chemistries, and processes, and even ceramic composites.
Mechanism Design
FUNdaMENTALS by Alexander Slocum
PDF Provides an overview of the basic principles of and physics behind design with real world applications.