Shrink the PCB to fit within 100x38mm
joshdboss opened this issue · 4 comments
This size is somewhat arbitrarily chosen. However, 100mm corresponds to the maximum size above which the price for a 4-layer PCB greatly increases on JLCPCB. The 38mm size cannot be change however, as that is the (approximate) inner diameter of the rocket.
Things that can be done to do this:
- Use SMD components
- Remove some parts of the PCB and put it in the nosecone (such as the total pressure port)
- Do not screw the Altimax or IMU directly on the PCB, but rather on the avionics bay itself
Additionally, it might be worthwhile to move the static pressure port onto its own board if the avionics bay is too far from the main board.
The voltage regulator should probably also be changed to an SMD DC to DC converter
This will actually almost certainly not be possible, due to the combined length of the Teensy (61mm) and sensor board (~50mm). Will likely have to resort to around 120mm, and pay the extra price for the slightly larger PCB. Alternatively, a 2-layer PCB might be sufficient.
Dimensions of the allocated space for the PCB (note that no dimension is final yet):
- Nosecone (A): 192mm long. Outer diameter 41.9mm. Thickness of walls not yet decided, but likely ~5mm, for an inner diameter of 31.9mm at the largest. Tangent square root profile. Should ideally fit a small payload
- Shoulder (B): 40mm long. Inner diameter 31.9mm
- Avionics bay (C): 100mm long. Inner diameter 38.7mm
- Inside coupler (D): 80mm long, minus cap, for a total length of ~60mm. Inner diameter 35.7mm
