30 Minute Dawn Mulvihill30 Minute Dawn Mulvihill

Presented by

Jacob Gomez

And

Daniel Heinrich

IntroductionIntroduction

More from less.Flying for time.Rubber powered.

IntroductionIntroduction

Dawn MulvihillAbsence of thermalsMost efficient model wins

PurposePurpose

Maximum utilization of energy1/8 inch rubber strip power sourceDawn Mulvihill ClassificationDouble the existing high time

Dawn MulvihillDawn Mulvihill

Must be rubber strip poweredProjected wing area under 300 in²No maximum flight timeModels flown at 7:00AM

RationaleRationale

Indoor models fly for more than one hour

Indoor models have limited ceiling

Outdoor models have virtually unlimited ceiling

Outdoor times 25% of indoor times

HypothesisHypothesis

Current designs not at maximum efficiency.

30 minute flight times should be attainable.

Utilization of energy. Maximization of

thrust.

Sample rubber motor test curve

010203040

0 20 40 60 80 100 120

Number of winds / 10

To

rqu

e (i

n/o

z)

ResearchResearch

Most research passed on orally

Current designs evaluated

Interviewed the “Top Guns” of Mulvihill.

The canard proven more efficient

Methods to Achieve GoalMethods to Achieve Goal

Aircraft DesignTesting EquipmentEvaluation and Analysis of DataFlight Testing

DesignDesign

DesignDesign

Equipment - testingEquipment - testing

ASSEMBLY KEY 1) Electric Motor

2) Photo Gate Sensor

3) Test Motor

4) Fixed Supports

5) Electric Balance (for calibration)

6) Light Gauge Steel Post to Balance Hard Joined

7) Double Strain Gauge Assembly

8) Attachment to Balance

9) Wire Shaft

A] Separate Balance Assembly

----] Indicates Cut Away

1

4 4 4 4

9

2

3

9

A

5

876

7

5 8

6

TOP VIEW FRONT VIEW

PRELIMINARY DESIGN FOR RUBBER MOTOR TORQUE TESTER

Jacob Gomez and Dan Heinrich

A A

Equipment - flyingEquipment - flying

Winding stooge.Stretch winding.Efficient winding.

Evaluation and AnalysisEvaluation and Analysis

Selection of motor with flattest torque curve.

Matching propeller design to torque output.Allowing the propeller to operate in a

narrower band of torque values.Propellers of varying design and initial

pitch settings.

Flight TestingFlight Testing

3 Models to be constructedFirst model approximately 170 in²Second model full size with standard propThird model full size with optimal prop

Time TableTime Table  8/03 9/03 10/03 11/03 12/03 1/04 2/04 3/04 4/04 5/04 6/04

Interviews and research                      

Model design                      

First model construction                      

First model testing                      

Second model construction                      

Second model testing                      

Rubber testing                      

Propeller design                      

Propeller testing                      

Final model construction                      

Final model testing                      

Project began in August 2003 with design and evaluation process. Table is subject to revision.

Closing ThoughtsClosing Thoughts

Maverick, you are cleared to buzz the tower.