Wednesday, July 17, 2013

Elliptical Fins Design

 
 
 

Newest Design 7/14/13

Can I make a rocket go higher and faster with an even newer design?  YES!!!
I used elliptical fins this time (but stuck to the cardboard because it was sturdy) and then I tried to more evenly tape the surface.  The nose cone was also an elliptical nose cone based on a 4-H design, in which I followed the 4-H instructions of cutting the nose from the bottom of another 2-liter pop bottle.  But, I left the cap on and used a ball of duct tape rolled up on top.  I filled in the neck of the cap with more duct tape, coiled like a snake that’s wearing a scarf. Finally, I took out two of the weights—using four instead of six.
Results:
1)  Launch 1:  I used 18 oz. of water and 30 pounds of air pressure.  The rocket went straight up into the air for seven seconds—no toppling or turning!!!  It went 196 feet in the air at 38 miles per hour.  Observations:  When the rocket came back down, there was some nose damage.  The duct tape on the nose smashed down and I couldn’t mold it back up.
2)  Launch 2:  I used 16 oz of water and 25 pounds of pressure.  The rocket shot up too early, but still made it straight up into the air for 6 seconds.  So, it flew 144 feet and 32.6 miles per hour.  Observation:  The nose cone damage is affecting the performance.
3)  Launch 3:  I used 16 oz of water and 19 pounds of air pressure, but the rocket flew back horizontally. Time to pack up for now!
Conclusion:  Of the different designs I tried, this rocket was the best design, for height and velocity, but I could only launch a few times before the nose cone collapsed.  Next time, I’ll find a sturdier design for the nose cone.