The current cost of the prototype is approximately $1,975.22. This was calculated to include the cost of extra material including screws and scrap metal. This satisfies Specification G1 by staying below $2500, but we would still like to continue to work to minimize the cost without sacrificing functionality or safety. The bill of materials for the prototype is shown in Table 10.
Table 10: Prototype Bill of Materials
| Subteam | Vendor | Item | Unit Cost | Quantity | Total Cost |
| Effort | AdaFruit Industries | Adafruit 9-DOF Absolute Orientation IMU Fusion Breakout – BNO055 – STEMMA QT / Qwiic | $19.95 | 2 | $39.90 |
| SparkFun | SparkFun Load Cell Amplifier – HX711 | $9.95 | 1 | $9.95 | |
| SparkFun | Wire Wrap Wire – Blue | $14.95 | 1 | $14.95 | |
| Digikey Electronics | Vishay Dale Through Hole Resistor | $0.59 | 6 | $3.56 | |
| EMI | sparkfun | Mini Speaker – PC Mount 12mm 2.048kHz | $1.95 | 1 | $1.95 |
| sparkfun | Arduino Mega 2560 R3 | $38.95 | 1 | $38.95 | |
| sparkfun | Toggle Switch – 125 VAC | $2.95 | 1 | $2.95 | |
| sparkfun | GTE Knob – Small | $0.95 | 1 | $0.95 | |
| sparkfun | Ribbon Cable – 10 wire (15ft) | $4.95 | 1 | $4.95 | |
| sparkfun | Rotary Potentiometer – Linear (10k ohm) | $0.95 | 1 | $0.95 | |
| adafruit | 3.5″ TFT 320×480 + Touchscreen Breakout Board w/MicroSD Socket – HXD8357D | $39.95 | 1 | $39.95 | |
| Mcmaster | Compression Spring Stock 36″ Long, 0.75″ OD, 0.59″ ID | $4.69 | 1 | $4.69 | |
| Mcmaster | Compression Spring 0.75″ Long, 0.24″ OD, 0.196″ ID | $10.84 | 1 | $10.84 | |
| sparkfun | Screw Terminal | $0.95 | 1 | $0.95 | |
| sparkfun | 10K Ohm Resistor | $1.20 | 1 | $1.20 | |
| JLC PCB | Circuit Board | $1.28 | 1 | $1.28 | |
| Amazon | SPST Latching Pushbutton Switch | $7.81 | 1 | $7.81 | |
| Amazon | 40mmx40mm mini fans (6 pack) | $10.99 | 1 | $10.99 | |
| Amazon | 40mmx40mm mini fan cages (20 cages in a pack) | $10.99 | 1 | $10.99 | |
| McMaster | General Purpose Aluminum Tubing 1″ OD, 0.058″ | $22.32 | 1 | $22.32 | |
| McMaster | General Purpose Aluminum Tubing 7/8″ OD, 0.035″ | $12.25 | 1 | $12.25 | |
| McMaster | 18-8 Stainless Steel Phillips Flat Head Screw- 5/8″ long | $5.17 | 1 | $5.17 | |
| McMaster | Multipurpose Aluminum disk- 4″dia , 1/2″ | $8.30 | 1 | $8.30 | |
| Amazon | PLA Spool, blue | $27.93 | 1 | $27.93 | |
| Amazon | PLA Spool, black | $22.99 | 1 | $22.99 | |
| Amazon | Waterproofing Spray | $15.19 | 1 | $15.19 | |
| Amazon | Elegoo EL-CP-004 120pcs Multicolored Dupont Wire 40pin Male to Female, 40pin Male to Male, 40pin Female to Female Breadboard Jumper Wires Ribbon Cables Kit for arduino | $6.98 | 1 | $6.98 | |
| Amazon | Todiys New 12Pcs for P55NF06 P55NF06L STP55NF06 50A 60V to-220 N-Channel Power Mosfet Transistors STP55NF06L | $9.95 | 1 | $9.95 | |
| Amazon | Electrical Wire 10 AWG 10 Gauge Silicone Wire Hook Up Wire Cables 20 Feet | $15.38 | 1 | $15.38 | |
| McMaster | Rubber Slip-on Feet | $6.40 | 1 | $6.40 | |
| McMaster | Stainless Steel Wing-Head Thumb Screw | $10.68 | 6 | $64.08 | |
| McMaster | Dowel Nuts for Wood | $7.86 | 1 | $7.86 | |
| Digikey Electronics | Voltage Regulator IC REG LIN POS ADJ 1.5A TO39-3 | $25.68 | 1 | $25.68 | |
| Propulsion | Amazon | Magliner 130502 Rotacaster Double Row Multi-Directional Wheels | $24.99 | 2 | $49.98 |
| ODrive Robotics | Dual Shaft Motor – D6374 150KV | $99.00 | 2 | $198.00 | |
| ODrive Robotics | 8192 CPR Encoder with Cable | $39.00 | 2 | $78.00 | |
| ODrive Robotics | ODrive V3.6 56V with connectors | $159.00 | 1 | $159.00 | |
| SDP/SI | Timing Pulley: 20 teeth | $13.31 | 2 | $26.62 | |
| SDP/SI | Timing Pulley: 14 teeth | $10.30 | 2 | $20.60 | |
| SDP/SI | 15.8 in Belt | $7.01 | 2 | $14.02 | |
| McMaster | Stainless Steel Ball Bearing | $19.83 | 4 | $79.32 | |
| McMaster | Stainless Steel Rotary Shaft – 1/2″ Diameter, 12″ long | $27.22 | 1 | $27.22 | |
| McMaster | Domed Head Sealing Blind Rivet with Plastic Seal | $9.75 | 1 | $9.75 | |
| McMaster | Corrosion-Resistant 316 Stainless Steel Socket Head Screw | $7.67 | 5 | $38.35 | |
| McMaster | Multipurpose 6061 Aluminum 90 Degree Angle | $19.35 | 1 | $19.35 | |
| McMaster | 18-8 Stainless Steel Socket Head Screw | $6.82 | 1 | $6.82 | |
| McMaster | Corrosion Resistant 3003 Aluminum Sheet (.190″ thick) | $52.27 | 1 | $52.27 | |
| McMaster | Easy to Weld 5052 Aluminum Sheet (.032″ thick) | $31.95 | 1 | $31.95 | |
| McMaster | Oversized Multipurpose 6061 Aluminum Sheet (0.250″ thick) | $26.29 | 1 | $26.29 | |
| McMaster | 18-8 Stainless Steel Socket Head Screw M4 x .7, 8mm | $6.78 | 1 | $6.78 | |
| McMaster | 18-8 Stainless Steel Socket Head Screw M3 x .5, 8mm | $4.52 | 1 | $4.52 | |
| McMaster | Side-Mount External Retaining Rings | $12.37 | 1 | $12.37 | |
| McMaster | 316 Stainless Steel Woodruff Key | $12.65 | 1 | $12.65 | |
| McMaster | Super-Corrosion-Resistant 316 Stainless Steel Socket Head Screw 4-40 Thread Size, 1/2″ Long | $6.61 | 1 | $6.61 | |
| McMaster | Super-Corrosion-Resistant 316 Stainless Steel Socket Head Screw 2-56 Thread Size, 1/2″ Long | $3.79 | 2 | $7.58 | |
| McMaster | Ball Joint Rod End, 1/2″-20 Thread Shank Trad Direction Right Hand | $7.08 | 4 | $28.32 | |
| McMaster | 18-8 Stainless Steel Socket Head Screw 1/2″-20 Thread Size, 1-1/4″ Long | $8.71 | 1 | $8.71 | |
| McMaster | 316 Stainless Steel Male-Female Threaded Hex Standoff | $3.13 | 10 | $31.30 | |
| McMaster | Passivated 18-8 Stainless Steel Phillips Flat Head Screw – 7/8″ long | $5.27 | 1 | $5.27 | |
| McMaster | Passivated 18-8 Stainless Steel Phillips Flat Head Screw – 1″ long | $6.33 | 1 | $6.33 | |
| McMaster | Dowel Nuts for Wood, 1/4″-20 Size, 0.472″ Long | $6.83 | 1 | $6.83 | |
| McMaster | Domed Head Sealing Blind Rivet with Plastic Seal | $9.75 | 4 | $39.00 | |
| McMaster | 10 mm bushing | $16.93 | 1 | $16.93 | |
| McMaster | 18-8 Stainless Steel Cup-Point Set Screw 8-32 Thread, 7/8″ Long | $6.97 | 1 | $6.97 | |
| McMaster | 18-8 Stainless Steel Socket Head Screw 1/4″-20 Thread Size, 3/4″ Long | $10.87 | 1 | $10.87 | |
| McMaster | Mortise-Mount Hinge with Holes | $1.57 | 3 | $4.71 | |
| McMaster | Zinc-Plated Steel Corner Bracket , 7/8″ x 7/8″ x 5/8″ | $0.43 | 16 | $6.88 | |
| Amazon | 48 V 10 AH lithium ion Battery pack | $199.00 | 1 | $199.00 | |
| McMaster | 18-8 Stainless Steel Pan Head Screw – 8/32 – 7/16″ Length | $6.06 | 1 | $6.06 | |
| McMaster | Steel U-Bolt 1/4″-20 Thread Size, 1-3/8″ ID | $5.60 | 1 | $5.60 | |
| McMaster | Steel U-Bolt 1/4″-20 Thread Size, 7/8″ ID | $5.00 | 1 | $5.00 | |
| McMaster | Bronze Sleeve Bearing | $2.77 | 2 | $5.54 | |
| McMaster | 18-8 Stainless Steel Hex Nut 1/4″-20 Thread Size | $3.87 | 1 | $3.87 | |
| McMaster | 18-8 Stainless Steel Socket Head Screw 1/4″-20 Thread Size, 1-1/2″ Long, Partially Threaded | $9.22 | 1 | $9.22 | |
| McMaster | Multipurpose 6061 Aluminum 5/8″ Thick x 1-1/2″ Wide | $8.89 | 1 | $8.89 | |
| McMaster | Multipurpose 6061 Aluminum 0.063″ Thick 4×24″ | $11.01 | 3 | $33.03 | |
| McMaster | Zinc-plated steel corner bracket 7/8″ x 7/8″ x 5/8″ | $0.43 | 4 | $1.72 | |
| McMaster | Aluminum loop clamp 1-3/8″ ID 2-18/” long | $5.34 | 1 | $5.34 | |
| McMaster | 18-8 Stainless Steel Socket Head Screw 10-32 Thread Size, 1-3/4″ Long | $10.51 | 1 | $10.51 | |
| McMaster | 18-8 Stainless Steel Hex Nut 10-32 Thread Size | $3.49 | 1 | $3.49 | |
| McMaster | 316 Stainless Steel Ring Shim 0.02″ Thick, 1/4″ ID | $4.97 | 1 | $4.97 | |
| McMaster | 316 Stainless Steel Ring Shim 0.016″ Thick, 1/4″ ID | $5.96 | 1 | $5.96 | |
| McMaster | 316 Stainless Steel Ring Shim 0.001″ Thick, 1/4″ ID | $12.61 | 1 | $12.61 | |
| McMaster | Extension Spring with Loop Ends 7″ Long, 1″ OD, 0.125″ Wire Diameter | $9.87 | 1 | $9.87 | |
| McMaster | Passivated 18-8 Stainless Steel Phillips Flat Head Screw | $3.75 | 1 | $3.75 | |
| McMaster | Multipurpose 6061 Aluminum Rectangular Tube 1/16″ Wall Thickness 1″High x 1″Wide x 1″ Length 1/16″ Wall Thickness, 1″ High x 1″ Wide | $6.11 | 1 | $6.11 | |
| McMaster | Passivated 18-8 Stainless Steel Pan Head Phillips Screw 8-32 Thread, 3/8″ long | $6.88 | 1 | $6.88 | |
| McMaster | Passivated 18-8 Stainless Steel Pan Head Phillips Screw 8-32 Thread, 1-1/4″ long | $10.47 | 1 | $10.47 | |
| McMaster | Extension Spring with Loop Ends 7″ Long, 1″ OD, 0.115″ Wire Diameter | $8.79 | 1 | $8.79 | |
| McMaster | Multipurpose 6061 Aluminum Bar, 1″x1″, 2 ft. long | $14.42 | 1 | $14.42 | |
| McMaster | High-Strength 7075 Aluminum Rod, 1/2″ Diameter, 2 ft long | $11.37 | 1 | $11.37 | |
| McMaster | Water and Steam Resistant EPDM O-Ring | $9.49 | 1 | $9.49 | |
| McMaster | Expandable Grommets for 1″ Hole Diameter | $10.42 | 1 | $10.42 | |
| McMaster | Extension Spring with Loop Ends 7″ Long, 1″ OD, 0.105″ Wire Diameter | $8.79 | 1 | $8.79 | |
| Home Depot | #8 x 1 in. Zinc Plated Phillips Flat Head Wood Screw (100-Pack) | $5.28 | 1 | $5.28 | |
| McMaster | Aluminum Unthreaded Spacer 1/2″ OD, 3/4″ Long, for 1/4″ Screw Size | $1.71 | 5 | $8.55 | |
| McMaster | 18-8 Stainless Steel Socket Head Screw 2-56 Thread Size, 3/16″ Long | $6.51 | 1 | $6.51 | |
| McMaster | 18-8 Stainless Steel Socket Head Screw 1/4″-20 Thread Size, 2-1/4″ Long, Fully Threaded | $15.30 | 1 | $15.30 | |
| Total | $1,975.22 |
The team has spent an additional $1,268.76 for testing equipment, tools, and extra components for testing or replacement. In total, the team’s budget is $3,388.56. This was higher than we anticipated, but we did not spare expenses to ensure that the project’s needs were met for the safety of team members and users. Additional expenses that were not included in the prototype bill of materials are shown in Table 11.
Table 11: Bill of materials for testing equipment, tools and extra components
| Subteam | Vendor | Item | Unit Cost | Quantity | Total Cost |
| all | Amazon | Drive Medical Silver Sport 1 Wheelchair | $109.29 | 1 | $109.29 |
| Effort | Harbor Freight | 2.5 Ton Leveling Scissor Jack | $36.99 | 1 | $36.99 |
| Home Depot | 2 in. x 4 in. x 96 in. Prime Whitewood Stud | $6.15 | 14 | $86.10 | |
| Home Depot | #9 x 2-1/2 in. Phillips Bugle Head Coarse Thread Sharp Point Polymer Coated Exterior Screws (1 lb./Pack) | $8.97 | 1 | $8.97 | |
| Home Depot | 1-3/4 in. x 48 in. Round Hardwood Dowel | $13.09 | 1 | $13.09 | |
| Home Depot | Cabinet Grade Plywood Panel (Common: 23/32 in. x 4 ft. x 8 ft.; Actual: 0.688 in. x 48 in. x 96 in.) | $45.98 | 1 | $45.98 | |
| Amazon | 10 FT USB Extension Cable | $8.99 | 1 | $8.99 | |
| Harbor Freight | 2.5 Ton Leveling Scissor Jack | $36.99 | 1 | $36.99 | |
| Home Depot | 1 in x 48 in Galvanized Steel Pipe | $24.60 | 1 | $24.60 | |
| digikey electronics | MOD ADXL335 5V READY 3AXIS +-3G | $14.95 | 1 | $14.95 | |
| sparkfun | Arduino Uno R3 | $22.95 | 1 | $22.95 | |
| sparkfun | SparkFun 9DoF IMU Breakout | $16.95 | 2 | $33.90 | |
| EMI | JLC PCB | Circuit Board | $1.28 | 4 | $5.12 |
| sparkfun | Break Away Headers – Straight | $1.50 | 5 | $7.50 | |
| sparkfun | Female Headers | $1.50 | 5 | $7.50 | |
| adafruit | 16mm Panel Mount Momentary Pushbutton – Red | $0.95 | 1 | $0.95 | |
| adafruit | Solder Wire – 60/40 Rosin Core – 0.5mm/0.02″ diameter – 50 grams | $5.95 | 2 | $11.90 | |
| sparkfun | Arcade Joystick | $19.95 | 1 | $19.95 | |
| sparkfun | Mini Speaker – PC Mount 12mm 2.048kHz | $1.95 | 1 | $1.95 | |
| sparkfun | Toggle Switch – 125 VAC | $2.95 | 1 | $2.95 | |
| sparkfun | GTE Knob – Small | $0.95 | 1 | $0.95 | |
| sparkfun | Rotary Potentiometer – Linear (10k ohm) | $0.95 | 1 | $0.95 | |
| sparkfun | Breadboard | $4.95 | 2 | $9.90 | |
| sparkfun | M/F Connector | $1.95 | 1 | $1.95 | |
| sparkfun | F/F Connector | $1.95 | 1 | $1.95 | |
| sparkfun | M/M Connector | $1.95 | 1 | $1.95 | |
| Mcmaster | Compression Spring Stock 36″ Long, 0.75″ OD, 0.59″ ID | $4.69 | 1 | $4.69 | |
| sparkfun | Screw Terminal | $0.95 | 1 | $0.95 | |
| amazon | SPST Latching Pushbutton Switch | $7.81 | 1 | $7.81 | |
| Amazon | Zip Ties | $8.99 | 1 | $8.99 | |
| Propulsion | McMaster | Multipurpose 6061 Aluminum T-Bar | $13.91 | 1 | $13.91 |
| McMaster | Multipurpose 6061 Aluminum Rod, 1/2″ Diameter, 2 ft. long | $4.77 | 1 | $4.77 | |
| McMaster | Stainless Steel Wing-Head Thumb Screw – 1/4″-20 Thread Size, 2″ Long | $10.68 | 4 | $42.72 | |
| McMaster | Multipurpose 6061 Aluminum Bar, 1″x1″, 2 ft. long | $14.42 | 1 | $14.42 | |
| SparkFun | Arduino Mega 2560 R3 | $38.95 | 1 | $38.95 | |
| McMaster | High-Speed Steel Round-Shank Reamer | $30.72 | 1 | $30.72 | |
| McMaster | 3 mm broach | $61.93 | 1 | $61.93 | |
| McMaster | High-Strength 7075 Aluminum Rod, 1/2″ Diameter, 2 ft long | $11.37 | 1 | $11.37 | |
| McMaster | Steel Extension Spring with Loop Ends, 7″ Long, 1.5″ OD, 0.177″ Wire Diameter | $11.29 | 1 | $11.29 | |
| McMaster | Corrosion-Resistant Extension Spring with Loop Ends 302 Stainless Steel, 7″ Long, 1.25″ OD, 0.148″ Wire Diameter | $20.49 | 1 | $20.49 | |
| McMaster | Extension Spring with Loop Ends 7″ Long, 1″ OD, 0.148″ Wire Diameter | $11.77 | 1 | $11.77 | |
| McMaster | Oversized Multipurpose 6061 Aluminum Sheet 5/8″ Thick 2″x24″ | $36.84 | 1 | $36.84 | |
| McMaster | Multipurpose 6061 Aluminum round tube 0.035″ wall thickness 1″ OD 1ft Length | $10.28 | 2 | $20.56 | |
| McMaster | Bushing for B Style Keyway Broaches, with Collar 1/2″ Diameter | $14.87 | 1 | $14.87 | |
| McMaster | Keyway Broach Uncoated, for 1/8″ Keyway Width, B Style | $72.94 | 1 | $72.94 | |
| McMaster | Left-Hand Tap Set, 1/2″-13 Sizes | $50.68 | 1 | $50.68 | |
| McMaster | Carbon Steel Screw Thread Die 1″ OD, 1/2″-13 UNC Left-Hand Thread | $15.91 | 1 | $15.91 | |
| MSC | 3/8″ Diam x 1/8″ Face Width, High Speed Steel, 6 Teeth, Shank Connection Woodruff Keyseat Cutter | $37.52 | 1 | $37.52 | |
| Testing | Home Depot | 1 in. x 8 ft. Lashing Strap (2-Pack) | $6.98 | 2 | $13.96 |
| Home Depot | Sakrete 50lb Play Sand | $5.25 | 4 | $21.00 | |
| Amazon | Ziploc Storage Bags with New Grip ‘n Seal Technology, For Food, Sandwich, Organization and More, Gallon, 75 Count | $8.89 | 1 | $8.89 | |
| Amazon | Hot Glue Gun Sticks 65 Count, Mini Size 4″ Length x 0.28″ Diameter for Industrial & Crafting, Small Glue Stick for Kids Crafts, No Ordor Good Adhesion Few Bubble,Quickly Melting Meeting DIY Needs | $10.79 | 1 | $10.79 | |
| Amazon | boruizhen Kids & Adult/Youth Knee and Elbow Pads with Wrist Guards 3 in 1 Protective Gear Set for Skateboarding Cycling BMX Bike Scooter Skating Rollerblading Riding (ADULT SIZE) | $19.79 | 1 | $19.79 | |
| Amazon | Hanging Weight Scale | 660 lb Digital Electronic Weighing Scale with Accurate Senesors | $27.99 | 1 | $27.99 | |
| Amazon | Mr. Pen- Packing Tape, 2 Pack, 2 inch Wide, 60 Yards, 1.9mil, No Smell, Shipping Tape, Packaging Tape, Packing Tape Rolls, Clear Packing Tape, Moving Tape, Box Tape, Packing Tape Refill, Mailing Tape | $6.99 | 1 | $6.99 | |
| Home Depot | 50 lb. Quikrete Premium Play Sand | $4.20 | 6 | $25.20 | |
| Home Depot | 12 ft. x 1 in. Ratchet Tie Down with S-Hook (4-Pack) | $8.97 | 2 | $17.94 | |
| Home Depot | 2 in. x 4 in. x 96 in. Prime Whitewood Stud | $7.98 | 8 | $63.84 | |
| Total | $1,268.76 |