🎵 Do you want to build a rocket? 🎵
- Jack Christensen
🎵 C’mon let’s hit the bay!
We need to finish harnessing the CANbus boards,
Before it flies away! 🎵
🎵 Can’t forget RLCS, and DAQ
It’s time to set up to fly.
Do you want to build a rocket?
We’re starting ops to launch the rocket.
(CONTROL: Open the Injector Valve)
Okay, bye. 🎵
There is nothing too special about harnessing. We mostly just want to ensure every line of the CANbus is connected to every board, trying for something close to a star topology. For each individual section of boards / sled we make a harness that connects all of those boards together and has a connector / wire to connect to the rest of the bus.
The harness needs to come apart at the vent section, since that is where we split the rocket in half for transportation. This is done with a pair of in-line Harwin Gecko connectors. Additionally we split the harness where it meets the recelec sled to allow the wire that goes beside the payload to be laid in beforehand. Otherwise, the harness joints are done with butt crimps and all ends terminate in our usual Harwin Datamate connectors. In the below diagram I’ve laid out a high level overview of how the harness splits and a few notable datamate connectors, but generally haven’t detailed the harnessing on each individual sled.
You will notice that there is no Gecko joint between the injector and the vent harnesses, they are in fact one large harness that spans the entire Ox tank. Below is the topology of the full harness, with every board that is connected:
We also can’t forget the terminating CAN resistors, one on each end of the harness. These are usually integrated into furthest apart butt crimps, ie the recelec and the injector sled harnesses.
Harness Sections
Recovery Harness
This harness is built around the recovery electronics sled. It has a male Gecko connector.
Upper Harness
This is a simple harness that gets laid into the upper body tube before anything else is inserted. It connects to the payload and picams (all with full size harwin connectors). It has a female Gecko connector at the top, and a male at the bottom. The majority of the length is a section of TEFZEL wire.
Lower Harness
This harness going around the ox tank and connects FAST and the vent section. It has a female Gecko connector at the top.