1. Adam Hertzlin Dustin Bordonaro Jake Gray Santiago Murcia Yoem Clara P14651: Drop Tower for Microgravity Simulation

2. Agenda Background List of experiments Engineering Requirements Concept Design Subsystem / System Analysis Data Analysis Software Files Risk Assessment Test Plan MSD II Schedule Bill of Materials

3. Project Summary Problem Goals Design & Build Drop Tower Vacuum Piping Structure Cost Effective Effective Cycle Time Aesthetically Pleasing Precision in Measurements Intuitive User Interface Access for Object Transfer Adaptability for Future Development Constraints The device is aesthetically pleasing The tower 6” – 12” Diameter The device can be operated year round The device must be moveable The system is safe to operate The project budget is $3,000 The project must be completed in 2 semesters

4. Project Deliverables Installed drop tower Detailed Design Drawings and Assembly Manual Bill of materials User’s Guide for operation Designed Lab Experiments Fun and Educational Experience for Students Technical Paper Poster

5. Customer Requirements Customer Rqmt. # ImportanceDescription CR19 Appropriate Tower Height CR29 Allow for Adjustable Pressure CR39 Display Tower Pressure CR49 Drop 2 objects simultaneously CR59 Drop objects with no horizontal motion CR69 Demonstrate standard local gravity within 1% CR79 Display important outputs accurately CR89 Allow full drop visibility and limit distortion CR99 Demonstrate drag vs. pressure CR109 Allow objects to be changed out CR119 Safe / Intuitive operation CR129 Educational and Inspiring CR133 Moveable Structure CR143 Design considers noise and power requirements and limits CR153 Components are properly maintained and stored CR163 Aesthetically pleasing CR173 Generate object lift mechanism concepts for future MSD CR183 Allow for further static experiments

6. Engineering Requirements Rqmt. # I Engr. Requirement (metric) Unit of Measure Marginal ValueIdeal Value SR19Measure Relative Object Positionmeter0 - 4.6>Tower Height SR29Measure Relative Object Drop Time% of Drop95 - 100%100% SR39Measure PressurePa0 - 101325 SR49Cycle Run Timemin1-10 mins1 min SR59Pressure Leak Rate MinimizedPa / secUnknown0 SR69Aesthetic Structure with SupportsYes / NoYes SR79No Horizontal Motionmeter0 - 0.0050 SR89Tube Collapse PressureF.O.S.0 - 55 SR99Timing difference of object releaseMillisecond0 - 50 SR103Tower HeightMeter2.1 - 4.615 SR113Tower Cross - Section (Diameter)Meter0.1524 - 0.20328 SR123Pump Flow Rateliter/min56 - 28310 SR133Impact Energy Dissipation MethodJoule (m min v final 2 /2)- (m max v final 2 /2)(m max v final 2 /2) SR143Air Intake - Tower Pressure Change Rateliter/minLow to High SpeedModerate Speed SR153Minimal Error in Calculations% error0 - 1%0% SR163Aesthetic Data DisplayYes / NoYes SR173Platform for Stationary ExperimentsYes / NoNo or YesYes

7. List of Experiments 1. Vacuum vs. Atmosphere – Fall Time Middle School Level (Science) Requires Vacuum Chamber No Calculations Needed 2. Gravity in Vacuum Conditions High School Level (Physics) Requires Complete System Start and End Time Required 3. Gravity in Atmospheric Conditions Undergraduate Level (Physics) Requires Release / Laser System Start and End Time Required 4. Calculate Drag Coefficient Undergraduate Level (Fluids / Numod) Requires Complete System Start and End Time Required 5. Decreasing Object Acceleration (Air Resistance) Undergraduate Level (Fluids) Requires Release / Laser System Multiple Data Points Required 6. Extra Vacuum Experiments Middle School Level (Science) Requires Vacuum Chamber No Data Required

8. Drop Tower Design

9. Tower Height Distribution

10. Total Height Available 11’ 7” 3.53 m Total Height of Tower 11’ 1.30” 3.385 m Drop Distance 8’ 3.77” 2.535 m

11. Results Total available height: 3.530m (11ft 7in) Total used height: 3.385m (11ft 1.3in) Total clearance: 0.145m (5.7in) Total drop distance: 2.535m (8ft 3.77in) In Vacuum: Total drop time with standard gravity is 0.719 s Speed at impact is 7.05 m/s (23.14 ft/s)

12. Full System Analysis

13. Release Mechanism Analysis

14. Solid Model

15. Section View

16. Motor Type w/ Specifications Speed at 6V 0.12 sec/60° 0.04 sec/60° 0.24 m/s Torque 61 oz-in 3.81 in-lb 0.43 Nm Weight 43g

17. Max Applied Force Gear Ratio 3 Length of the door 1.5 in (0.038 m)

18. Micro-Controller

19. Future Use Compatibility The tower that will be built will have the capabilities of hosting a continuous lift system within the pipe. All the other subsystems would be able to work as regular with the moving system. The only thing that would have to be address would be the modification of the software so it can monitor the displacement of the platform.

20. Displacement Platform This platform would be the one responsible to catch the objects at the bottom of the tower and to bring them to be pick up by the release mechanism.

21. Object Positioning Assembly This assembly will allow the object to be picked up by the release mechanism doors. A stopper in the release mechanism fixture will activate the motion upwards, and gravity would do the work to bring it back to a regular position.

22. Object Positioning Assembly

23. Frame Analysis

24. Tube Deflection Assumes a worst case, where the entire structure is laying horizontally, 3.048 m (10ft) tower. The tube is fixed at the riser clamps pictured above, and is analyzed with two or three riser clamps, at either 8 or 4ft (2.44 to 1.22m) apart. With 2, ymax is -1.5mm (-.058in) With 3, ymax is -.093mm (-.0037in) So, three riser clamps will be used as deflection is decreased dramatically

25. Riser Clamp Connections

26. Critical Tipping Scenario

27. Tower Supports

28. Frame Subsystem Analysis

29. Subcomponent Selection Rotation joints at top (for laser adjustment): From McMaster-Carr ¼” binding post ¼” bolt Wheels and axels: Wheels from McMaster-Carr, each supports 250 lbs. Axels from McMaster-Carr, analysis follows. Height adjustment/leveling: From McMaster-Carr, 6 required, each supports 250 lbs

30. Axel Calculations

31. Laser & DAQ Analysis

32. Specifications & Setup Micro-Epsilon ILR 1030-8/LC1 10ms response time -- over ~2.54m (8’3.8”) this is ~ 70 data points (fall time ~0.72 seconds in a vacuum) +/- 2.5mm accuracy in position 4 - 20 mA output related to distance fallen, and must be calibrated. So, 4mA = 0m and 20mA = 2.6m Divergence of 0.0859° gives a ~4mm dot at 2.54m (8’3.8”) Voltage will be created from mA output via a 249 ohm resistor, for DAQ purposes; DAQ will be NI USB-6008; 10 kS/s acquisition speed. Can see though polycarbonate, as long as it passes through before start of data collection (data collection starts at 0.2m (7.9in) and angle of entry +/-5° from perpendicular to surface Laser is visible dot (important for alignment and calibration) M12 connector for power and interface, requires 10-30 VDC M12 cable has pigtail bare lead ends Mounted via M5 through holes

33. Frame Mounting Components

34. Bending of Links application

35. Pipe Analysis

36. CAD Drawing

37. Critical Negative Pressure Desired Factor of Safety > 3 ✔ Pipe Dimensions Courtesy of Engineeringtoolbox.com *Specifications for white PVC

38. Energy Dissipation Analysis

39. Material Selection Polystyrene Beads (Bean Bag)

40. Critical Dimensions of Impact Absorption material

41. .

42. Pump Analysis

43. Specifications Free Air Displacement – 6.25 CFM @ 60Hz Horse Power – 1/2 HP RPM – 3440 @ 60Hz Ultimate Vacuum – 15 microns (2 Pa) Intake Ports (male flare) – 1/4", 3/8" SAE Male & 1/2" ACME Male Oil Capacity – 15 oz./450 ml Dimensions – 13.7'' x 5.6'' x 10.4'' Shipping Weight – 25.4lb/11.5kg

44. Evacuation Time Equivalent Length, Le, based on pipe losses Effective Pump Speed based on pipe geometry and flow regime Evacuation Time based on Volume, Pump Speed and flow regime Total Evacuation Time (no leaks): 6.12 mins Conductance (cfm) Total Le (ft.)ViscousTransitionalMolecular Main Pipe60.04268347.2315.449.0 Secondary Pipe3.916135.42.41.5 Sp (cfm) Effective Pump Speed (cfm) ViscousTransitionalMolecular Combination of Pipes6.25 1.701.17 Evacuation Time4.741.38N/A

45. Connection Port Analysis

46. Polycarbonate Plate Cable Sealing Compound Shrink Tubing By recommendation of Dr. Robert Pearson and a price vs. effectiveness research. The use of potting compound is preferable for our application Apiezon Sealing compound Q is an economic option to seal a leak in a vacuum system. It is sufficiently firm at room temperature to remain in position, yet soft enough to be molded by hand and is readily removed Some Properties: temperature range, °C: -10 to + 30 Vapor pressure @ 20°C, in torr: 1x10 -4 Packaging: 1 kg Cable Feed Through

47. Pipe Connection - Bottom Connection allows for vacuum hose to be connected though the bottom polycarbonate cap Seals against each side via gasket Allows for pipe to be screwed on inside drop tower to pass by polystyrene beam bag Brewer’s Hardware - P/N WLFM12F12 - Weldless Bulkhead - 1/2" MPT X 1/2" FPT

48. Pipe Fitting Analysis

49. Pipe End Cap Fittings Top Bottom

50. Tower Fittings

51. Pressure Gauge Analysis

52. Digital Vacuum Gauge Specifications Range Atmospheric to 0 microns Max Working pressure 400 PSIG Accuracy +/- 10% Powered By 9V Battery Operating Temp. Range 32° - 120° F (Compensated) -22° - 158° F (Non-Compensated) Mechanical Connection Standard 1/4” female SAE refrigerant hose type with core depressor

53. Labview / Matlab Code

54. Vacuum Conditions

55. Atmospheric Condition

56. Uncertainty in Measurements Position (x, x0), where x0=0m +/- 0.0025m from laser +/- 0.0005m from first measurement timing Time (t, t0) ), where t0=0s +/- 0.0001s from DAQ (10,000 samples per second) Mass (m) +/- 0.0001kg from scale Projected Area (A) +/- 0.0001 m^2 from measurement device Pressure (P) +/- 10% from pressure gauge Temperature (T) +/- 1 degree C from thermometer Drag Coefficient (Cd) +/- 0.1 from estimation (maybe better if calculated first)

57. Example #1 – Gravity in Vacuum

58. Example #2 – Gravity in Atmosphere

59. Labview Front Panel

60. Matlab Code

61. Subsystem Test Plan #Main ComponentDescriptionStatus 1 Catching System Dissipate Objects Energy from FallingOpen 2 Release Mechanism Quick Release w/ No Horizontal MotionOpen 3 Tower Frame Test Tower Stability During OperationOpen 4 Laser Sensor Best Position to Track Objects FallOpen 5 DAQ Device Appropriate Signal is Programmed and FunctionalOpen 6 Labview Program Compare Results to Analytical PredictionsOpen 7 Pressure Gauge Calibrate and Test Entire Pressure RangeOpen 8 Vacuum Pump Attach Pressure Gauge Directly to PumpOpen 9 Vacuum Tube & Fittings Test Ultimate PressureOpen

62. Fully Integrated System Test Plan #Main ComponentDescriptionStatus 1Object Fall TimeVacuum vs. Atmospheric ConditionOpen 2Gravity - VacuumCalculating Gravity through LabviewOpen 3Gravity - AtmosphereCalculating Gravity through LabviewOpen 4Drag CoefficientCalculating Drag Coefficient in MatlabOpen 5Drag vs. PressureCalculated Fall Velocity over Pressure RangeOpen 6 Stationary Platform & ObjectsObserve Behavior of Objects in VacuumOpen

63. Risk Assessment – High Risk Items Only IDRisk ItemEffectCause Likelihood Severity Importance 1High Leak Rate Loss of Vacuum Noisy Increased depressurize time Bad Sealant Gaps in o-rings Surface impurities 326 2 Laser Sensor Looses Item Loss of data (position and time) Improper sensor alignment Sensor range inadequate Power loss 236 3 Unsuccessful Release of Objects Items does not fall Horizontal motion occurs Unsynchronized release Mechanism doesn’t open Release timing off Loss of power 224 4Pipe Implodes Safety Hazard Project ruined Pipe wall thickness Material 133 5Tower Falls Over Safety Hazard Damages to Surroundings Project Ruined Poorly supported Earthquake Weak structure 133

64. MSD II Schedule – Part 1

66. Bill of Materials

67. Bill of Materials Continued

70. Questions?