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Combat Buggy Parts List and Bill of Materials

Build Options Overview

Component Category Budget Build Performance Build
Total Cost $130-150 $170-190
ESC Repeat Robotics Dual ($19.99) Weka 20A v2.2 ($40+)
Motors Repeat Motors Mk 4mm ($20) Repeat Motors Mk 4mm ($20)
Other Components Same Same

Electronic Components

Motor Speed Controllers (ESCs)

Option 1: Budget Build - Repeat Robotics Dual ESC

  • Part: Repeat Robotics Budget Brushed Dual ESC (2-4S)
  • Price: $19.99
  • Supplier: itgresa.com
  • Features: Dual channel brushed ESC, 2-4S LiPo compatible
  • Weight: TBD
  • Quantity: 1

Option 2: Performance Build - Weka 20A v2.2 Dual ESC

  • Part: Weka 20A v2.2 Dual ESC
  • Price: $40+
  • Supplier: justcuzrobotics.com, also available through itgresa.com
  • Features: 20A per channel, 3g weight without wires, overcurrent/undervoltage protection, mixing enabled
  • Weight: 3g (without wires)
  • Quantity: 1

Drive Motors

  • Part: Repeat Motors Mk 4mm
  • Price: $20 for 2 motors
  • Supplier: itgresa.com
  • Specifications: Brushed gear motors, 4mm shaft with grub screw attachment, 3S LiPo compatible
  • Quantity: 2

Power System

Battery

  • Part: OVONIC 3S LiPo 450mAh
  • Specifications: 11.1V, 80C discharge rate, XT30 connector, 35g weight
  • Price: $20-25 for 4-pack (recommended for competition rotation)
  • Supplier: Amazon
  • Quantity: 4-pack recommended (minimum 2)

Battery Charger

  • Part: ISDT PD60 Balance Charger
  • Price: $19.99
  • Specifications: 60W, 6A max, 1-4S LiPo capable, USB-C input (5-20V)
  • Features: Balance charging, upgradeable firmware, silent cooling
  • Supplier: Amazon
  • Quantity: 1

Kill Switch

  • Part: Lynx Anti-Spark Kill Switch
  • Price: Varies by vendor
  • Specifications: High-current anti-spark design for combat robotics
  • Supplier: itgresa.com, justcuzrobotics.com, various combat robotics vendors
  • Quantity: 1

Control System

Microcontroller - Budget Option

  • Part: Xiao ESP32C3
  • Price: $10
  • Features: WiFi capability, compact form factor, Arduino IDE compatible
  • Quantity: 1

Microcontroller - Advanced Option

  • Part: Xiao ESP32S3
  • Price: $17
  • Features: Enhanced features over ESP32C3, WiFi capability
  • Quantity: 1

Controller

  • Part: Xbox Standard Controller
  • Price: $60
  • Features: Wireless connection to microcontroller, familiar ergonomics, reliable operation
  • Supplier: Amazon, electronics retailers
  • Quantity: 1

Electrical Components

Power Connectors

  • Part: XT30 Connectors (Male and Female)
  • Specifications: High-current battery connections, male for battery side, female for robot side
  • Supplier: Amazon, electronics suppliers
  • Quantity: 2-4 pairs (spares recommended)

Wiring

  • Power Wires: 16-18 AWG for main power and motor connections
  • Signal Wires: 22-24 AWG for control signals
  • Heat Shrink Tubing: Various sizes (2mm, 4mm, 6mm)
  • Solder: 60/40 rosin core, 0.6-0.8mm diameter
  • Supplier: Amazon, electronics suppliers

Mechanical Components

Fasteners

Torx Screws (NEW)

  • Part: M3 × 12mm Torx Flat Head Thread-Forming Screws

  • Drive Size: T8

  • Application: Chassis mounting, plastic component attachment

  • Features: 90° countersink, thread-forming for plastic

  • Supplier: McMaster-Carr

  • Quantity: TBD

  • Part: M2 × 0.4mm × 6mm Torx Flat Head Screws

  • Drive Size: T6

  • Material: Zinc-plated steel

  • Application: Motor mounting, electronics mounting

  • Supplier: McMaster-Carr

  • Quantity: TBD

Standard Fasteners

  • Part: M4 × 0.7mm × 8mm Grub Screws (cup point)

  • Application: Wheel attachment and securing points

  • Supplier: McMaster-Carr

  • Quantity: 8

  • Part: M2 × 0.40mm × 5mm Flat Head Threading Screws

  • Application: Various chassis connections

  • Supplier: McMaster-Carr

  • Quantity: TBD

  • Part: M4 × 0.70mm × 20mm Button Head Screws

  • Application: Motor mounting, structural connections

  • Supplier: McMaster-Carr

  • Quantity: 4

Shoulder Bolts

  • Part: 5/16" × 7/8" or 1" Shoulder Screws (1/4"-20 thread)

  • Application: Pivot points, structural connections

  • Supplier: McMaster-Carr

  • Quantity: 2

  • Part: 1/4"-20 Nylon-Insert Lock Nuts

  • Application: Securing shoulder screws

  • Supplier: McMaster-Carr

  • Quantity: 2

Assembly Materials

Thread Locker

  • Part: Loctite Medium Strength (Blue) Thread Locker
  • Application: All critical threaded connections
  • Note: Apply only during final assembly
  • Supplier: Hardware stores, Amazon
  • Quantity: 1 small bottle

Component Mounting

  • Part: 3M Dual Lock Tape
  • Application: Securing components without permanent attachment
  • Features: Strong, removable mounting system
  • Supplier: Amazon, industrial suppliers
  • Quantity: 1 roll

Mechanical Hardware

Chassis

  • Material: Lightweight aluminum or titanium frame
  • Source: Custom fabrication or 3D printing from provided CAD files
  • Files: Available in cad/ directory
  • Weight: Optimized for 1lb weight budget

Wheels

  • Part: Foam wheels with hex cores
  • Files: CAD files available for 3D printing cores
  • Application: Drive and support wheels
  • Quantity: 4 (typically)

Tools Required

Hand Tools

Torx Keys (UPDATED)

  • T6 Torx L-Key: 1-1/4" overall length (for M2 screws)
  • T8 Torx L-Key: 1-3/4" overall length (for M3 screws)
  • Quality: Professional grade recommended (Wera, Wiha, Bondhus)
  • Supplier: McMaster-Carr, Amazon, tool suppliers

Hex Keys

  • Sizes: 5/32" (4mm), 2.5mm, 2mm, 1.5mm
  • Additional: Appropriate size for M2×5 screws
  • Quality: Good quality L-keys or ball-end sets
  • Supplier: Hardware stores, Amazon

Other Hand Tools

  • 7/16" Wrench: For lock nuts
  • Needle or Micro Flathead Screwdriver: Fine adjustment work
  • Wire Strippers: For 16-24 AWG wire
  • Precision Scale: 0.1g accuracy for weight verification

Electrical Tools

Soldering Equipment

  • Soldering Iron: 25-40W with fine tip, temperature controlled preferred
  • Solder: 60/40 rosin core, 0.6-0.8mm diameter
  • Flux: Additional rosin flux for clean joints
  • Heat Gun or Hair Dryer: For heat shrink tubing
  • Multimeter: For continuity testing and voltage measurement

Testing Equipment

  • Test Blocks: Elevate robot for safe wheel testing during assembly
  • LiPo Battery Tester: Verify cell voltages
  • Work Light: Good lighting for precise work (minimum 500 lux)

Safety Equipment

  • Safety Glasses: Required during soldering and assembly
  • Sand Bucket: For smothering LiPo fires during motor/robot testing
  • Fire Extinguisher: Electrical fire rated for general electrical safety
  • LiPo Charging Bag: Fire-safe charging container
  • Well-Ventilated Area: Or fume extractor for soldering

Suppliers and Procurement

Primary Suppliers

  • itgresa.com: Repeat Robotics ESC ($19.99), Repeat Motors ($20), Lynx Kill Switch, Weka ESCs
  • justcuzrobotics.com: Weka 20A v2.2 ESC ($40+), advanced combat electronics
  • Amazon: OVONIC batteries ($20-25), ISDT charger ($19.99), Xbox controllers ($60), XT30 connectors
  • McMaster-Carr: All fasteners, precision hardware, thread locker, professional tools

Lead Times

  • Combat Robotics Parts: May have longer lead times, order early
  • Standard Electronics: Usually 1-3 days from Amazon
  • Precision Fasteners: McMaster-Carr typically next-day delivery

Budget Planning

  • Budget Build: $130-150 | Performance Build: $170-190 | Tools: $50-100 (one-time)

Weight Budget Analysis

Component Category Typical Weight Notes
Electronics 120-150g ESC, motors, battery, microcontroller
Chassis 150-200g Aluminum/titanium frame
Fasteners 20-30g All screws, bolts, hardware
Wheels 40-60g Foam wheels with cores
Miscellaneous 30-50g Wiring, mounting materials
Total Target ~450g 4g margin for 454g limit

Weight Optimization Tips

  • Minimize wire length - every inch adds weight
  • Use appropriate fastener sizes - don't oversize
  • Choose lightweight chassis materials
  • Remove excess material where structurally safe

Quality and Specification Notes

Critical Specifications

  • XT30 Polarity: Male connector on battery (larger terminal = positive)
  • Thread Pitch: M2 × 0.4mm fine pitch for precision mounting
  • Battery Capacity: 450mAh optimized for 1lb weight budget
  • ESC Current Rating: Must handle motor stall current safely

Quality Recommendations

  • Torx Tools: Quality bits prevent stripping
  • Battery Safety: Use balance charger, never leave charging unattended. Keep sand bucket nearby during testing - LiPo fires must be smothered, not extinguished with water
  • Fastener Quality: Use proper grade fasteners from reputable suppliers
  • Competition Spares: Carry extra XT30 connectors and fasteners

Revision History

Version Date Changes
1.0 2025-07-08 Initial consolidated parts list creation
Added specific Torx fastener specifications
Consolidated information from ASSEMBLY.md and AGENDA.md
Added detailed supplier information and pricing

Note: This parts list consolidates information previously scattered across multiple documents. All builders should verify current pricing and availability before ordering, as costs and suppliers may change.