Here is an updated CAD design for the buoy, V03 (design V02 has been printed and is in the shape of a sphere, blog post needs to be updated). The water tight cylinder idea has been postponed currently in order to more quickly prototype and test the electronics. The design is meant to be printed in two halves on my Printrbot Simple metal with a 6″x6″x6″ printer volume.
The design has also been simplified right now to only include GPS, Li-po battery, Arduino Mega, temp sensors, and an Xbee for transmitting the data to a base station only a 20-50 yards away.
This is the first version of the prototype that will float as the surface of the water. The top portion of the hull will be secured to the bottom hull with 8 machine screws, and will be sealed with a large o-ring and silicone grease.
Anticipated issues with this design:
1.) Will need to test the effectiveness of the sealing the top and bottom hulls together, since the 3D printed parts will likely warp slightly.
2.) Additionally, the large antenna is not centered on the buoy, so this may cause buoycancy problems that can hopefully be offset by using ballast weight.