Part one here
We decided to try the spring powered parachute system one last time before scrapping the idea. We wanted to know if the length of the springs effects the power of the parachute system.
The “power” of springs is measured in rate(lb/in). Rate is how much force (in lbs) it takes to compress the springs 1 inch (2.54cm). The rate of the springs we were using was 14 and the length was 3.41in (8.66cm). It took ~47.74lbs of force to fully compress the springs. Due to their small size, they were shorter than the parachute tubes and thus did not extend beyond the top of the tube. We theorized that if we used longer springs that extended above the tube, we might get better performance. While the new springs (rate: 6.6 length: 5.63in) were on their way, we began to work on the necessary modifications to the parachute system. We made several changes, the most important of which was upgrading the hinges to strengthen them.
Over the next few days, we printed and assembled the new 4th generation parachute system. By the time it was complete, the new springs had arrived and we were ready to begin testing.
Wanting to gradually scale up the amount of pressure the parachute system was subjected to, for our first test we did not load the system with anything and instead compressed the springs until the lid could be closed. However, we were unable to get the system to deploy. As we mentioned in our last post, we swapped servos after the ones we had planned to use did not meet our specs. For a time, these servos worked but, they were not meant to handle the forces they were being subjected to. While the servos were not damaged, it was clear we would have to upgrade.
The failures did not stop there, shortly after this test we accidentally fried the receiver when we plugged the battery in backwards.
We are now waiting for the new parts to arrive before we can continue preparing for our flight. If you have been following our progress, you have noticed that the past two months have been fraught with setbacks, and this has certainly effected morale. But the learning that has come with these mistakes has been valuable and we continue to be committed to completing Project Redirect