3D Printed Bidirectional Transition for BT-70 and BT-80 with Avionics Bay

New for 2023! We've upgraded our 3D printed transition design to work equally well in either direction--large end forward or small end forward.  This makes it a great component for TARC 2024 rules, which require a smaller payload tube than the airframe tube.

Rocketry Works' unique and sturdy 3D printed transition includes quick and easy threaded access to an internal altimeter bay.  This transition connects BT-70 and BT-80 tubes, and can be oriented large end or small end forward. Laser cut plywood user-configurable flat bulkhead or bulkheads with shock cord mount on each end support the use of dual ejection or fragile payloads.  A laser cut altimeter sled fits securely inside the transition, with mounting hardware for common altimeters.

The transition comes in 3 parts: the small end shoulder, the transition, and the large end shoulder. To assemble, select the flat bulkhead or the shock cord mount bulkhead for each end, secure the bulkheads in each end, and thread the shoulders to the transition. Use the included nylon stand-off bolts to secure your Pnut, APRA, or Stratologger CF altimeters to the altimeter sled. Or, use a Jolly Logic Snap Mount to mount a Jolly Logic altimeter to the sled. Unscrew the threaded sections to access the avionics bay, and slide the altimeter sled between the anchor tabs. Secure the sled with the included nut and bolt. Before flight, tape or epoxy the aft vent ports closed; vent ports aft of a change in airframe diameter can produce unreliable altimeter readings.

Includes 3 transition pieces, flat bulkheads, bulkheads with shock cord mounts, altimeter sled, and mounting hardware. Altimeters not included.

Product Documentation

Important assembly instructions are available here.