3 variations of the non-segmented leg design

This week, we delved further into different non-segmented leg variations. After proving its thrust capabilities, we shifted our attention to making it lightweight. Initially, we played around with the properties of the 3D printer. The first iteration on the left was printed at 20% fill and weighed 6g. The next iteration was lengthened and printed at 13% fill and weighed 5g. It can be seen that our print was actually incomplete as the filament had ran out. However, it actually proved advantageous as the absence of the last few layers lowered its mass and there was just enough print for it to be secured to the axle. The last iteration on the right was a shot in the dark and a desperate attempt at lowering mass. Although coming in at a whopping 2g, its lack of sturdiness was worrying and we settled on the second iteration as displayed in the middle.

 

CAD of platform

In order to secure the propulsion device to the balloon, we utilised the platform idea conceived by our seniors as it was flexible and offered a large surface area for attachment.

The elevator idea was also reviewed and because our balloon is targeted to fly at relatively low speeds, it is expected to only increase air resistance and not work like the elevators of a plane as planned. Hence, we reverted back to the bladder mechanism as done by our seniors.

We planned to try out balloon construction soon and Tony managed to find the specialised iron that our seniors bought to make their balloon. They employed a technique called heat sealing, where two pieces of Mylar sheets are placed on top of each other and are ironed along the edges to form a seal.