End of Week 5

Week five is now over and we have learned quite a bit. We spoke to the Aero department at Mt. SAC and it seems that there is no wind tunnel for us to test the various air frames and airfoils we plan to produce. Because of this, we will probably have to build our own unless we find one we can use off campus. We also made our first attempts at flying our test plane. Although we were unable to fly it successfully in either of our three attempts, we have realized that we made quite a few mistakes in the design our our first air frame. Considering this and the fact that the front of the air frame sustained quite a bit of damage in our third attempt  at flight, we are deliberating whether or not we should try to fix our existing frame or simply build a new one. This will be determined later this week. Other than that, the following was accomplished in week five:

• Society of Physics Students
• We won the campus clean up event that took place at Mt. SAC on Saturday.
• DBF Team
• A preliminary budget for the project was written out
• Airfoils / Air Frame
• The rudder was attached to the back of the plane prior to any test flights
• Problems regarding the configuration of the servos were fixed
• The airfoil equipment was initially placed on the wrong side of the wing. The first two test flights were made with this configuration. The third test flight was made with the equipment replaced on the correct side.
• One of the servos broke as a result of one of the test flights
• New equipment was purchased
• A new servo to replace the broken one
• Carbon fiber tubing to reinforce the wings
• Nylon hinges
• Pushrods
• Servo gear set
• Notes
• The airfoils seemed to be sustain very little damage due to any of the test flights
• We realized the foam used to build the test plane is not very dependable, as the plane accumulated a lot of damage throughout the testing process
• The elevators did not work as we intended them to, as the plane generated a ton of lift in the last test even when the elevators were not being activated
• The front of the air frame seemed to be too large. It needs to be much smaller in subsequent designs.
• The center of gravity was measured to be along the wings in all of its tests, just as it should be.
• The plane passed a glide test.
• Power / Propulsion
• An issue with one of the connections involved in powering the motor inhibited it from generating the thrust that we measured in the lab. Because of this, the first flight test failed.
• The issue was diagnosed and fixed after that test.
• Even after the connection issue was fixed, the motor did not generate enough thrust to allow the plane to fly in the second test flight.
• New equipment was purchased
• Male and female connectors
• 5000 mA battery
• Propellers
• Dimensions: (11 x 8) in^2, (10 x 5) in^2 , (11 x 7) in^2 , (10 x 10) in^2
• NiMH Battery Pack
• 7.2 Volts, 2000 mAh
• Our new battery pack was put in series with our old battery pack, thereby yielding 14.2 Volts
• This new configuration was used to power the motor in some preliminary testing and it seemed to increase the thrust that the motor generated by a substantial amount.
• Some of the bigger propellers were tested with the new battery configuration, but they seemed to generate less thrust than the 9x6 in^2 propeller we had already been using.
• The new battery configuration and the 9x6 in^2 propeller were used in the third test flight. Although these seemed to generate enough thrust to fly the plane, we did not have enough control of the plane for it to fly successfully.
• The 9x6 in^2 propeller broke as a result of the third test flight.

Week Five will focus on the following:

• DBF Team
• Write up a travel budget for the trip to Tucson, Arizona
• Airfoils / Air frame
• Determine whether we want to fix our first air frame prototype or start anew
• Design testing rig for in the wind tunnel to gain lift and drag components from wing
• Get rockets for sizing and design consideration
• Complete optimization of scoring formula
• Analyze three designs for testing
• Begin design for a wind tunnel
• Power / Propulsion
• Determine NiCd vs NiMh
• How long will battery last at full power (20 amps)
• Feasibility of splitting into two packs for multiple engines
• Look into placing ducted fans in series (turbine)
• Test the motor with the new battery configuration
• Test different sized propellers