End of Week 6

As the previous post explained, a lot was accomplished this past week in regard to our second prototype, which Jason has dubbed "The Anteater" due to it's long nose. Considering a majority of what was done was described in the previous post, this will serve as description of the testing that took place in Friday's meeting involving the various propellers we recently purchased.

The first series of testing involved hanging our motor on a force sensor while connected to a speed controller and a 14.4 Volt battery configuration. The motor was then activated for about ten seconds, at which point the thrust data accumulated in this period was averaged. This process was done three times with each propeller.  The following data was collected through this process.

Trial	10 x 5 Propeller	10 x 10 Propeller	11 x 7 Propeller	11 x 8 Propeller
1	12.50 N	11.26 N	14.42 N	14.00 N
2	12.10 N	10.80 N	14.43 N	13.61 N
3	11.72 N	10.30 N	14.26 N	13.63 N
Average Thrust:	12.11 N	10.79 N	14.37 N	13.71 N

We then wanted to see how the thrust was affected as the battery life was used up. To do this, we fully charged the 14.4 Volt battery pack and hooked it up to the motor while the 11 x 7 propeller was attached. This propeller was chosen for this test because it put out the greatest thrust values in the previous test. We then used a volt meter to read the number of volts that the battery used to power the motor, at which point we ran the motor until the volt meter read about 12.5 Volts. We fit the data collected through logger pro with a line, at which point we used the time that it ran (293.46 seconds), the slope of the line that was fit to the data (-.01235), and a constant that the linear fit gave us (15.6) to find the average thrust given off by the prop-motor through that time.  The following was done by hand to find this value:

Average Thrust = (ʃ((-.01235)t+15.6)dt)/293.46 , where the integral is evaluated from t = 0 to              t = 293.46

Further testing similar to this will be continued this week.

Week seven will focus on accomplishing the following:

• Airfoils / Air Frame
• Finish construction of "The Anteater"
• Start testing the rockets that we ordered early in week seven
• Complete optimization of scoring formula
• Gather materials necessary for the construction of the wind tunnel
• Start the construction of the wind tunnel
• Power / Propulsion
• Determine NiCd vs NiMh
• More testing with the new battery configuration and new propellers