This was the key hardware custom made piece of this quest. Not only did it had to hold all the components in place, like the GPS transmitter or the antenna, it had to be just ideal for the camera to be able to shoot great video and the cell phone to take cool pictures from below. All of this while allowing the power bank to energize both of them.
Every single item had to be placed properly so that once the box was being lifted by the balloon, it stayed balanced and the movement wouldn’t disturb the gadgets. Furthermore, the container box was a challenge because aside from carrying all of the components, it had to be as light as possible!
The materials
- Styrofoam box
- Thermal Insulating board (Foamular 250)
- Cutters
- Carving Drill
We also needed a lot of patience and imagination.
The construction
The Styrofoam box we bought had originally the following specifications:
- Outside dimensions: 15-⅞”x 15-⅞” x 15-⅝”
- Inside dimensions: 12-¾” x 12-¾” x 12-½”
We realized that it was to be too big and divided it in two parts of 15-⅞” x 15-⅞” x 7-¼”. Half box was enough space for all our required equipment to fit in.
After fixing the box, we needed to figure out where we were going to set all of our equipment. We started with the most crucial part: selecting the best place for the camera (we used a SJCAM SJ4000) and the cell phone. To find out the best position for the devices we created a couple of stencils, one for the cell phone with a hole where the camera should be, and another one for its case. We decided to put the cell phone at the bottom and the SJ4000 on one side of the box.
Next, we cut out the holes for both cameras with a cutter. We had to widen the outside hole so the least amount of Styrofoam would block the recording and the pictures. Using the cutter and the carving drill we managed to widen the outside part of the box creating a pyramidal hole without damaging the integrity of the box.
Then, we needed to figure out a way to fill all the gaps inside the box and keep it insulated from the freezing temperatures of the exterior. We agreed to use a thermal insulating board; we cut six layers approximately the size of the inside dimensions 12-¾” x 12-¾”x 1” each.
The details
Afterwards, we needed to decide the optimum place and position for the GPS transmitter and the power bank, so that the weight of the box stay balanced. After a few tests putting them inside the box and tying them, the position was chosen: both the power bank and the GPS transmitter would be set horizontally in the middle of the box.
The next step was to create the spaces on each thermal insulating layer for the camera, the GPS transmitter and the power bank. The first layer needed no modification at all, this was going to be the first layer to keep the cellphone still at the bottom of the box, and to have an extra insulating layer for the power bank. For the second layer we had to start carving the space needed for the other three components; this was the base for all other layers. We drew the edge of the SJ4000 on one side of the layer and then we drew the edge of both the GPS transmitter and power bank together in the middle of the layer. Then using the cutter and the carving drill we started removing the excess of insulating material in order to have them still during takeoff and landing. We did the same procedure with the third and fourth layer. We kept the fifth and sixth layer the same, except for a little hole in the middle to let the antenna cable out.
The challenge
The box was now completed and all the components were kept still and insulated, but we still had one tiny problem: the specifications for the balloon ideal payload was 800 grams, and the total weight of our box was 1,545 grams!!! So now we needed to figure out a way to reduce the extra weight without compromising the Styrofoam box, and the insulation.
We had the following weights:
- GPS transmitter: 189g.
- Antenna: 27g.
- Power bank: 176 g.
- Cell phone: 139 g.
- Parachute: 43g.
- SJ4000 camera: 134g.
- Styrofoam box: 237 g.
- 6 layers of thermal insulating: 600g (100g each).
The only weight we could get rid off was the thermal insulating layers, so what did we do? We removed the two top layers, but it wasn’t enough, so we also cut the middle left layers, and from layers two and three, we removed 2 pieces of 10cm x 14cm x 2.5cm on each side (where the power bank and GPS transmitter were). With these changes we were able to reduce 245 grams of the total weight, giving us now a new total of 1,300 grams. Finally the box was completed and ready for launch.
