Critical Design ReviewCritical Design ReviewThe Fab FourThe Fab Four

Jeremy ConradJeremy Conrad Electronics ExpertElectronics Expert

Javier MatamorosJavier Matamoros Thrust GuruThrust Guru

Greg WilliamsGreg Williams Wood Working SpecialistWood Working Specialist

Luis PerezLuis Perez Computer TechnicianComputer Technician

“Airship…

Critical Design ReviewCritical Design ReviewThe Fab FourThe Fab Four

Jeremy ConradJeremy Conrad Electronics ExpertElectronics Expert

Javier MatamorosJavier Matamoros Thrust GuruThrust Guru

Greg WilliamsGreg Williams Wood Working SpecialistWood Working Specialist

Luis PerezLuis Perez Computer TechnicianComputer Technician

“Airship…

of Doom!”

OutlineOutline

I.I. MissionMissionII.II. Final Design IntroductionFinal Design IntroductionIII.III. Scale DrawingsScale DrawingsIV.IV. General StructureGeneral StructureV.V. MaterialsMaterialsVI.VI. Weight AnalysisWeight AnalysisVII.VII. Control SystemsControl SystemsVIII.VIII. Other AdjustmentsOther AdjustmentsIX.IX. ConclusionConclusion

Fab 4 World Domination PlansFab 4 World Domination Plans

To Crush All To Crush All Who Oppose Who Oppose

UsUs

The Fab 4 MissionThe Fab 4 Mission

Through the use of knowledge acquired Through the use of knowledge acquired during the semester and extensive testing during the semester and extensive testing of our various options to produce a final of our various options to produce a final product. This final product should be of a product. This final product should be of a caliber that will meet our design caliber that will meet our design requirements, and allow us to participate requirements, and allow us to participate competitively in the race. competitively in the race.

Final Design IntroductionFinal Design Introduction

We arrived at our final design after careful consideration of other options. The other designs were eliminated after consideration of weight, drag, number of motors, and ability to steer. Four and two balloon designs, as well as the 2 other designs presented at PDR were eliminated because they were not as competitive.

Scale Drawings (side view)Scale Drawings (side view)

Scale Drawings (top view)Scale Drawings (top view)

Scale Drawings (front view)Scale Drawings (front view)

General StructureGeneral Structure

As previously presented, we chose a “net” As previously presented, we chose a “net” design. We have a basic frame around design. We have a basic frame around the balloons, which will be supported by the balloons, which will be supported by the netting. In this configuration, most of the netting. In this configuration, most of the load is taken by the balloons and nets.the load is taken by the balloons and nets.

General StructureGeneral Structure

Nets have been replaced by lightweight, Nets have been replaced by lightweight, strong fabric paper. Holes will be cut in strong fabric paper. Holes will be cut in the paper in non-crucial spots to further the paper in non-crucial spots to further reduce weight while keeping necessary reduce weight while keeping necessary strength.strength.

MaterialsMaterials

Main structure: Balsa Main structure: Balsa woodwood

Standard Elmer’s Standard Elmer’s wood gluewood glue

Fabric paper “netting”Fabric paper “netting” BalloonsBalloons Electronics packageElectronics package

Weight AnalysisWeight Analysis Balsa: Balsa: 170 g170 g Motors (2):Motors (2): 420 g420 g Props (2): Props (2): 10 g10 g Servos (2):Servos (2): 86 g86 g Receiver :Receiver : 27 g27 g Receiver Bat:Receiver Bat: 94 g94 g Netting:Netting: 80 g80 g Batteries +wire: Batteries +wire: 235 g235 g

Total:Total: 1.122 kg1.122 kg

Control Systems (Yaw)Control Systems (Yaw)Yaw control will be achieved through differential thrust. The two large motors are placed on the long crossbar to enable a turning moment.

Control Systems (Pitch)Control Systems (Pitch)

The original design involved a rotating The original design involved a rotating crossbar manipulated by a single servo.crossbar manipulated by a single servo.

We decided this would be difficult to We decided this would be difficult to implement, and might require much implement, and might require much additional weight. Our final design additional weight. Our final design involves a servo attached to each motor, involves a servo attached to each motor, both on a single control channel.both on a single control channel.

Control Systems (Roll)Control Systems (Roll)

Roll instability was a concern during Roll instability was a concern during PDR. This issue was resolved by PDR. This issue was resolved by lowering the center of weight by lowering the center of weight by hanging the electronics package and hanging the electronics package and additional payload under the balsa additional payload under the balsa frame with wires.frame with wires.

Other Design AdjustmentsOther Design Adjustments

Joints between lengthwise and crosswise Joints between lengthwise and crosswise members originally had a very small members originally had a very small contact patch. Small pieces of balsa were contact patch. Small pieces of balsa were attached to the sides of contact patches to attached to the sides of contact patches to increase contact area and joint strength.increase contact area and joint strength.

Motors will be attached to the servos, Motors will be attached to the servos, instead of directly to the crossbars to instead of directly to the crossbars to provide pitch controlprovide pitch control

ConclusionConclusion

Though there remains some testing to be Though there remains some testing to be done, and some minor issues to resolve, done, and some minor issues to resolve, there are no major problems which stand there are no major problems which stand between us and a final product. We see no between us and a final product. We see no obstacles between us and a smooth finish. obstacles between us and a smooth finish.