DASH - Parachute Tests
The Parachute Deployment Systems have now been fully tested, and has concluded that the right amount of black powder is 0.85 grams. These tests have been conducted by attaching Arch to a RC controller, allowing me to manually light the pyrotechnic charges instead of having it timed.
Through these test, I was also able to find out a problem with the piston design. The hole in the middle of the piston (that was used for the rope to go through) was just a little to big, allowing for a parachute to catch on fire. Luckily, I was using paper towel as the parachute in the tests to see if they had any chance to light on fire. This problem will be solved using an aluminum foil cup surrounding the parachute, which was tested in the last experiment.
Charge Test #1
I had first tested the charge alone, to see if the method I use to create the charge actually works. The charge contained 1.3 grams of black powder. I originally thought was barely going to fully deploy the parachutes, however I later found out that I couldn't have been more wrong. After this test, I was confident moving into testing the fully system.
Parachute Test #1
After testing the pyrotechnic charge alone, I added all the parts to the parachute deployment system, except for the parachutes themselves. This included the body tube, piston, and nosecone. This test used the same amount of black powder has the previous test, 1.3 grams. During the test, the explosion of the black powder was much more powerful then I had expected, and blew the nosecone off with so much force that it ripped the metal eye-bolt out of it. Moving forward I was sure to almost halve the amount of black powder.
Parachute Test #2
For the second parachute test, I had lowered the amount of black powder all the way to 0.8 grams. I had also added paper towel to simulate the parachutes. When fired, the nosecone went up the perfect distance so that the rope did not over stretch. However, after the test I noticed that the paper towels that I had added were slowly burning. This prompted me to add a layer of aluminum foil between the piston and the parachutes.
Parachute Test #3
For the final test I used a pinch more black powder then previously used, as I wanted the nosecone to reach its peek height faster. I also added an aluminum foil cup to contain the paper towel, that again will simulate the parachutes. This time only one of the paper towels started to burn, and it was no where near as severe as the last test. So finally concluding the tests, 0.85 grams of black powder will be used along with an aluminum foil cup with a thicker bottom will be used to safely return Dash to the ground during launch.