GIGA II – Nose cone avionics and electronics bay

Nose cone avionics

The nose cone avionics of the GIGA II have been re-built after the CATO. Keeping the original basic design with some minor modifications. One of the failure modes evident was that the nose cone tip with central M6 threaded rod was missing and ripped itself, including the nut, through an aluminium U-profile taking along the G10 board holding the electronics with it. Mitigating action is an added washer between the profile and the nut. However it is expected that is a similar CATO happens the same failure can happen again.

Improvements:
The downward looking Mobius mini camera was re-located from an outside camera shroud to be housed inside of the nose cone looking out. The design of the nose cone electronics is dictated by the rather large 4000mAh 2S LiPo and keeping it centered in the nose cone to reduce the likelihood of coning as much as possible. Re-using the original nose cone – with the hole for the pull pin switches already drilled and prevent drilling any extra holes – proved quite the engineering challenge. So, although the arrangement of parts and electronics can be more compact, it is a result of existing rocket parts. In the Mobius GUI the “auto record external power” was toggled to start the recording. The camera was connected via a pull pin switch and step down converter set to 5V to an angled USB mini cable.

Nose cone avionics consisting of:

  • 3D printed assembly containing the following segments:
    • Mobius mini camera
    • Battery holder containing the main battery packTurnigy 4000mAh 2S intelligent transmitter LiPo pack.
    • Pull pin 4 switch array with three out of 4 pull pin switches connected to the: camera, Talky GPS and AM emergency beacon.
    • Spacer for central nut and washer
  • Two step down converters set to 4.2V & 5V.
  • 1W Talky GPS by LD. Featuring both APRS position messages as well as live audio feedback of altitude and position. A stepdown converter set to 4.2V sits between the battery and Talky GPS.
  • 433mHz AM emergency beacon by LD on a separate 850mAh 1S LiPo.

Electronics bay

Similar to the nose cone avionics the GIGA II electronics bay has been re-built from the ground up after the CATO. Almost all components were replace with new replacements such as: RDAS Tiny, battery holder, pull pin switches, U-profiles and G10 board. The basic design was kept the same but the CATO of GIGA I showed two failure modes which are mitigated by design improvements:

  • The 9V battery was ripped from its holder and broke the tie wrap sending it through the electronics bay and disconnected from the RDAS – hence no recovery / deployment of parachutes.
    • Mitigating action: added a stainless steel tie wrap.
  • The pull pin switches were ripped from the 3D printed switch holder due to the screws holding the switches in place not gripping too well in the 3D printed material
    • Mitigating action: added a G10 board and through all M3 bolts with nuts.

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