This document describes the approach and detailed design of a full-scale model of the Black Brant III sounding rocket.
The overall construction follows standard practice and materials currently in ue for high-power amateur rockets. The main materials consist of:
- Cardboard tubes
- Fibreglass composites
- Carbonfibre composites
- Epoxy adhesives
Electronics used consist of commercially available flight computers. Specifically the Egg Timer Proton.
The overall design is provided here
The design is based on original drawings
The airframe is constructed from cardboard postal tubes 10" diameter and 3mm wall thickness. These tubes are wrapped in two layers of XXX fibreglass. The design uses two sections of airframe coupled together with an avionics bay. The aft section of the airframe is slotted to allow for “through the wall” mounting of the fins
The fins are constructed using a core comprised of 3mm plywood laminated with carbon fibre. This core is “sandwiched” on both sides with 3mm plywood shaped to the profile of the original fin design shown here.
The complete fin assembly is then laminated with fibreglass. The Vacuum bagging technique is used for all fin lamination to ensure optimal epoxy/cloth ratios.
The initial design for the fins is provided here.
The nose cone is constructed using 3d printed core, which is wrapped with layers of fibreglass. The thickness of the core is 3mm.
Due to the limitations of build area, the core is printed in 9 pieces with a plate at the base of each. The plates and forward section have a 12.75mm hole to allow for a central rod for use in the fibreglassing process.
The design uses a 98mm motor mount. Initial flights will use a 75mm CTI motor adapted to 98mm
Initial simulations are provided here