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P14651: Drop Tower for Microgravity Simulation

P14651: Drop Tower for Microgravity Simulation . Adam Hertzlin Dustin Bordonaro Jake Gray Santiago Murcia Yoem Clara. Agenda. List of experiments Engineering Requirements Concept Design Subsystem / System Analysis Data Analysis Software Files Risk Assessment Test Plan

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P14651: Drop Tower for Microgravity Simulation

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

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

  4. Engineering Requirements

  5. Drop Tower Design

  6. Tower Height Distribution

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

  8. Results • Total available height: 3.53 m (11ft 7in) • Total used height: 3.385 m (11ft 1.3in) • Total clearance: 0.145m (5.7 in) • Total drop distance: 2.535m (8ft 3.77in) • In Vacuum: • Total drop time with standard gravity is .719s • Speed at impact is 7.052 m/s

  9. Full System Analysis

  10. Release Mechanism Analysis

  11. Solid Model

  12. Section View

  13. 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

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

  15. Micro-Controller

  16. 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.

  17. 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.

  18. 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.

  19. Object Positioning Assembly

  20. Frame Analysis

  21. Tube Deflection • Assumes a worst case, where the entire structure is laying horizontally, 10ft (~3m) 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 -.058in (-1.5mm) • With 3, ymax is -.0037in (-.093mm) • So, three riser clamps will be used as deflection is decreased dramatically

  22. Riser Clamp Connections

  23. Critical Tipping Scenario

  24. Tower Supports

  25. Frame Subsystem Analysis

  26. 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

  27. Axel Calculations

  28. Laser & DAQ Analysis

  29. Specifications & Setup • Micro-Epsilon ILR 1030-8/LC1 • 10ms response time -- over ~2.6m (8.5 ft) this is ~ 70 data points (fall time .727 seconds in a vacuum) • +/- 2.5mm accuracy • 4-20 mA output related to distance fallen, and must be calibrated. So 4mA=0m and 20mA=2.6m • Voltage will be created from mA output via a 249 ohm resistor, for DAQ purposes; DAQ will be NI USB-6008 • 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

  30. Frame Mounting Components

  31. Bending of Links application

  32. Pipe Analysis

  33. CAD Drawing

  34. Critical Negative Pressure • Desired Factor of Safety = 3-4 *Specifications for white PVC Pipe Dimensions Courtesy of Engineeringtoolbox.com

  35. Energy Dissipation Analysis

  36. Material Selection • Polystyrene Beads (Bean Bag)

  37. Critical Dimensions of Impact Absorption material

  38. Critical Dimensions of Impact Absorption material • Assuming a Object 1 mass of 1kg. • Assuming a Coefficient of Restitution of 0.712 • Assuming a Ball Radius of 0.0508 m (2 in) • . Volume =Mass / density Area= Pi x Radius^2 Height = Volume / Area Height of energy absorbing material = 0.16 m ̴ 16 cm (6.30 in)

  39. Pump Analysis

  40. 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

  41. 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

  42. Connection Port Analysis

  43. Cable Feed Through 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 Sealing Compound Cable Polycarbonate Plate Shrink Tubing

  44. 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

  45. Pipe Fitting Analysis

  46. Pipe End Cap Fittings Top Bottom

  47. Tower Fittings

  48. Pressure Gauge Analysis

  49. Digital Vacuum Gauge Specifications • Range • Atmospheric to 0 microns • Max Working pressure 400 PSIG • Acurracy • +/- 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

  50. Labview / Matlab Code

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