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Interim Review #2

Interim Review #2. RAV Team Matthew Allgeier Kevin DiFalco Daniel Hunt Derrick Maestas Steve Nauman Jaclyn Poon Aaron Shileikis. Introduction. RFA’s Subsystems Design Summary Current Issues Schedule Status Critical Path Budget Status. Requests for Action (RFA’s).

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Interim Review #2

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  1. Interim Review #2 RAV Team Matthew Allgeier Kevin DiFalco Daniel Hunt Derrick Maestas Steve Nauman Jaclyn Poon Aaron Shileikis

  2. Introduction • RFA’s • Subsystems • Design Summary • Current Issues • Schedule Status • Critical Path • Budget Status

  3. Requests for Action (RFA’s) • Check Finish Specification on Control Surface Dynamic Sealing Surface

  4. Design Summary – Mechanical

  5. Hydrodynamic RFA • Check Finish Spec on Seal Surface for Control Surface Seals • Optimal rod surface finish < 8in (0.2 microns) • Type 303 Precision Stainless Steel shafts have a finish of 10 microns • Sales Engineers at Eclipse engineering confirmed that this finish would be adequate for low speed intermittent use

  6. Hydrodynamics – Summary • Required Airfoil Torque • Change in Req. deflection speed (servo spec) • New Torque: 125 oz-in w/out misc. losses • New Airtronics 94358Z Servo • 200 oz-in (High-Torque) • 1.54 x 0.79 x 1.47 (small – space constraint)

  7. Hydrodynamics – Issues • Custom Servo Coupler • Unable to locate small size coupler • Misfit Shaft to Coupler via Heat • Servo • Problem: Can not rotate 180º for LSM Test • Solution: Remove Airfoil during Subsystems Test

  8. Buoyancy – Design Summary • Machined Parts • 90% Complete • Still to Machine • Cylinder • Parts to Acquire • Batteries • 4 DuraTrax Receiver NiCd Flat Pack 6 Volt • 2200mAh (600mAh required per motor) • Length x Width x Height: 3-1/4“ x 1-3/4“ x 5/8" • Weight: 4.8 oz [BUOY 1] Buoyancy Piston Cylinder Assembly

  9. Buoyancy – Issues • Inner Cylinder Sealing • Machine inner bore for smooth sealable surface • Lubricate o-rings to reduce friction • Test design thoroughly [BUOY 2] Buoyancy Piston Cylinder and Piston Head

  10. Data Acquisition – Summary/Issues • Design Summary • Extech mini anemometer - Velocity • Electronics tested and partially manufactured • Omega PX180 pressure transducer - Depth • Electronics tested and partially manufactured • Battery voltage monitor (2) • 4 external channel HOBO data logger • Current Issues • Integration time

  11. Propulsion – Design Summary and Issues Design Summary • Change in propeller size • Change in motor mount • Change in coupling for Motor/shaft/prop Issues • Need to check on all orders made recently [PROP 1] Old Motor Mount Configuration [PROP 2] Tail cap on CNC milling machine

  12. Propulsion – Status [PROP 3] Finished Tail on CNC Lathe [PROP 4] Finished Tail and CNC Lathe Setup

  13. Communications – Summary • Components • Tx - Futaba 8UAPS • Rx - Futaba FP-R148DO, PCM 1024 • 8-Channel, 72.330 MHz, 3.12 ft whip antenna, 0.75 W • Using less channels than expected due to Switch Capabilities • Coaxial Cable (new) • Trainer Cable (new) • 1/8” diameter Fiberglass Antenna Mast • Testing Configurations • Nominal Configuration • Propulsion Subsystems Test • Buoyancy Subsystems Test (use Trainer Cable) • Range Testing Results • Signal Loss at > 100 m

  14. Communications – Testing Configs [COMM 2] Propulsion Test Config [COMM 3] Buoyancy Test Config [COMM 1] Nominal Config

  15. Communications – Issues • Problem #1: Receiver/Antenna Location • Metallic Housing = EM wave interference • Underwater = Loss ~300 dB/m • Solutions: • Move Antenna outside of RAV via shielded Coaxial Cable • Match Coaxial Cable Impedance to both Receiver & Antenna • Problem #2: Comm during Buoy Subsystems Test • Depth > Antenna Height • Solution: • Cable (3m?) from Tx to Rx for Buoyancy Subsystems Test • Plan: Use commercial components

  16. LSM – Issues and Progress • Issues - Model Assumptions • Control surfaces • Assumes the CS to turn 90° to minimize drag • Antenna • Drag not included in model • Inertia • Ignored in model • Progress • Current design testing complete • New design testing in progress

  17. LSM – Testing Results • Testing encounters • Results affected by ambient water conditions • Mechanically sensitive • Latex • Solenoid • Wire connection • Insufficient voltage to solenoids • Test results • Consistent with assumptions • Optimized parameters • Frequency = 15 Hz • Exit diameter = 0.40” [LSM1] – Test results from 4” model sub at Clare Smalls Pool. Performed with 2 5EP soft-shift solenoids.

  18. LSM – New Design • New Design will not be incorporated into the RAV • Motor/Flywheel/Piston system • Eliminates mechanical discrepancies in solenoids • Provides absolute displacement • Adjustable frequency • Testing in progress • Possible insufficient motor torque • Results & Purpose • Improves current design • Provides a foundation for future projects [LSM2] – Partial CAD of 2nd Design

  19. Full Systems Testing – Design Changes/Issues • Leak Test Change • CO2 Test Discarded • Sublimation Rate too Slow • Mechanical Valve Added • Advantage: External Pressure Gauge

  20. Critical Path #1 • Pre-Leak/Hyperbaric Test (*Bottleneck!!) • Physical Integration • Mid-Section • Weld & Seal Bulkheads • Drill Mid-Section Holes • Weld & Seal LSM • Integrate & Seal Buoyancy (Piston-Cylinder & Hoses) • Antenna & Pressure Transducer Static Seals • Leak Test Valve • Tail • Weld & Seal Bulkhead • Pressure Fit Control Surfaces Dynamic Seal • Mount Servo’s, Coupler & Shaft • Pressure Fit Propulsion Dynamic Seal • Mount Shaft • Electrical Integration • Data Acquisition • Pressure Transducer to HOBO • Comm • Tx to Rx • Rx to all subsystems • Leak Test (Friday, 19 March)

  21. Critical Path #2 • Hyperbaric Test (Friday, 26 March) • Post-Hyperbaric Test • Physical Integration • Mid-Section • Antenna Mast • Anemometer Mount • Payload Tray • Electronics Box • Batteries & Wiring • Tail • Motor & Mounting Hardware • Propeller • Shroud & Mounting Hardware • Electrical Integration • Data Acq • Anemometer to HOBO • Battery Voltage Monitor • Communications • Rx to all subsystems • Tx Programming • Functional Subsystems Tests • Pool Testing

  22. Miscellaneous Comments/Issues • Slightly Behind Schedule • Death Week + Spring Break • Avg. 15+ hrs/wk/student vs. scheduled 12 hrs/wk • Outstanding Receipts • ACard Update to $6,500 • Battery Cycling & Charging • Total Machine Shop Hours: ~625 hrs

  23. Manufacturing Hours Breakdown

  24. Updated Schedule

  25. Before Spring Break

  26. After Spring Break

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