Buoyancy Analysis Inputs:
Buoyancy Mechanical Design Johnson Electric Motor (12V) –High rpm (16,000 –Lightweight (7.50 oz per motor) Alexander Engel Gear Set –Proven for piston systems Threaded Piston Rod –6 mm Piston Head –Aluminum –Machined in-house Cylinder –Aluminum –Machined in-house –ID x OD x thickness: 2” x 2.25” x 0.125” 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 Sealing –Precision Associates Inc. –Piston Head Seal ” ID x 0.075” C/S x 2.0” OD –End Cap Seal ” ID x 0.025” C/S x.287” OD
Buoyancy Electrical Design Ballast Tank switch (BTS-II) –Proven system for remote submarines –Electronic (no servos) –Connects directly to Receiver Stop-full micro switch Stop-empty micro switch Trim switch
Buoyancy Test Plan Static Motor Strength Test (Feb 7 th ) Verify System Produces force to operate at a depth of 20m –Horizontal Load Cell Resolution: 1 lb Range: 50 lb – 400 lb Accuracy: +/- 1 lb –Expected Results: 141 lb force –Results: 11 lb force (Error due to incorrect moment arm calculation) Buoyancy Subsystem Test (Never Achieved) Verify descent and ascent rate –Antenna Marking w/ Stopwatch Range: 0 – 6 ft Resolution: 0.5 ft –Expected Results: 3.0 ft/sec –Minimum Requirement: 0.5 ft/sec Overall System Test (Never Achieved) Verify system remains neutrally buoyant at given depth –PX236 Pressure Transducer Range: 0 – 60 psi Bandwidth: 2 Hz Resolution: 0.1 psi Accuracy: +/- 1.5% –Expected Results: 3.0 ft/sec with neutral buoyancy (< 0.2 psi change) –Minimum Requirement: 0.5 ft/sec with 1 minute neutral buoyancy [1]
Weight Comparison (Pounds) SectionModelActualDifference Payload Tray Tail Assembly LSM Assembly Hull Assembly Nose Assembly TOTAL Neutral Buoyant Weight: lbs