1. Buoyancy Analysis
Inputs:

2. 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
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: 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

3. 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

4. Buoyancy Test Plan Static Motor Strength Test (Feb 7th)
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]