Why?
We decided to create a box that would be able to store the circuitry pertaining to our sampling system as well as the respective components of the system (bottle and winch). This box would then be attached to the bottom of the drone and allow our system to work.
Box
We initially planned on creating an enclosed box that could enclose and store our sampling system.
We considered including a door mechanism that would release the container of the sampling system together with the string that is wound around the winch at once when unlocked. We hoped that through this design, it would provide enough force for the container to be at least 3/4 submerged in the ash when it lands. We were planning to use a latch mechanism to open the doors with the help of a motor.
On top of that we thought to include an additional platform that could be inserted in the box. This platform serves a few purposes. It provides a surface for the circuitry related to the sampling system to be kept and also has extensions to mount the motor and winch of the system.
As observed in the picture, the box has an in-built ridge where the platform can be mounted.
We then realized that our box was far too heavy for our drone as we had a limited and small payload to work with. Hence, we redesigned the box to make up less volume. To do this, we made successive horizontal bars progressively thinner from the top to the bottom of the chamber. The rationale behind this was that it would preserve the stability and integrity of the box while enabling us to minimize the mass of of our box.
We also made the ridge less steep.
After some re-evaluation, we made the decision to ditch the door idea as it was unnecessary. This idea involved too much extra circuitry and mass to our overall sampling system. On top of that, the motor that we intended to use was jittery and we did not know what was causing it. The box was redesigned to be shorter in height so that the sampling system would be attached at the base of the box rather than in the middle of it. The platform was also adjusted to lower the vertical position of the hooks to make spaces for the masses that would be wound up together with the string on the winch.
Winch
We first created a basic winch that we could wind the string around. Once we got our motor to start working, this winch could unravel the string.
However, considering the design of our box, we needed a way to mount the winch without restricting its rotation. This is why we created an extension to the winch such that it can be held up by a hook extension on the platform of the box.