4 Wheel DIY Robot Platform Kit with Metal Servo Bearing Kit Steering

Specifications

• Chassis Material: High-strength Acrylic/Metal Composite (depending on revision) with rigid mounting points.
• Steering Mechanism: 4-Wheel / Front-Wheel Active Steering capability (configuration dependent).
• Drive System: 4x DC Geared Motors (Rear/All-Wheel Drive capable).
• Steering Actuation: Compatible with Standard Size Servos (e.g., MG995/MG996R) – Servos typically sold separately or included in premium bundles, check box contents.
• Bearing Type: Metal Ball Bearings for reduced friction and high durability.
• Tires: High-grip rubber compound for indoor and smooth outdoor surfaces.
• Payload Capacity: Approx. 2-3 kg (Motor dependent).
• Voltage Rating: 6V - 12V DC (Recommended 7.4V Li-Ion or 11.1V LiPo).
• Dimensions: [Standard 1:10 or 1:12 Scale footprint] – Spacious enough for Raspberry Pi, Lidar, and Battery packs.

Applications

• Autonomous Parking Assistant: Use ultrasonic sensors and the steering mechanism to code self-parking algorithms (Parallel/Perpendicular).
• ROS Navigation Node: Perfect base for running SLAM (Simultaneous Localization and Mapping) as the steering allows for predictable odometry compared to skid-steer bots.
• Agricultural Robotics Prototype: Simulate crop-row navigation where turning radius is critical to avoid damaging plants.
• Remote Inspection Vehicle: Stable platform for mounting FPV cameras for under-vehicle or pipe inspections.
• Advanced Line Follower: Use steering angles for PID correction instead of differential speed, resulting in smoother high-speed line tracking.

Project Evolution

• The Prerequisites (Where you started) You’ve likely built a 2-wheel drive "Smart Car" or a 4WD Skid-Steer bot. You understand digitalWrite for motors and basic differential drive logic (Left Motor Forward, Right Motor Back = Turn).
• The Feature Upgrade (What this unlocks) This chassis unlocks Kinematic Modeling. You will move from simple On/Off turning to calculating Steering Angles. You can implement Ackerman Geometry (Inner wheel turns more than outer wheel) to eliminate wheel scrub. This is closer to real automotive engineering than any standard robot kit.

Virtual Technician & Wiring Guide

• ⚠️ Critical Safety Warning: Never power the Drive Motors and the Microcontroller from the same weak power source (like a 9V battery). The voltage drop during steering will reset your Arduino.
• Recommended Power: Use a 2S (7.4V) or 3S (11.1V) Li-Ion pack.
• Servo Power: Servos are power-hungry! Power them directly from a specific BEC or Buck Converter (5V 3A), NOT from the Arduino's 5V pin.

Basic Pin Mapping Strategy (Arduino Example):

• Drive Motors: Connect to L298N Driver -> Pins 5, 6, 9, 10 (PWM capable).
• Steering Servo: Connect Signal to Pin 11 (PWM). VCC to External 5V.
• Encoders (If added): Interrupt Pins 2, 3.

Attention: The manufacturer has changed the big copper gear to the hard plastic gear, this hard plastic gear is more tough and durability than the copper gear. It will not affect the use.

Frequently Asked Questions (Technical FAQ)

• Can this robot rotate in place (Zero Radius Turn)?
  No, unlike skid-steer robots, this uses a steering mechanism. It has a minimum turning radius, similar to a real car.
• What servo motor fits this kit?
  It is designed for Standard Size servos (dimensions approx 40x20x36mm), such as the MG995, MG996R, or DS3218.
• Does it come with encoders?
  The standard kit usually does not include encoders, but the motors often have extended shafts to attach external encoder discs.
• Can I use a Raspberry Pi to control it?
  Yes, but you will need a Motor Driver HAT or an external driver board to interface with the 12V motors and 5V servos.
• What is the maximum speed?
  This depends on the voltage supplied. At 12V, standard yellow motors run at roughly 200-300 RPM, offering a walking pace (approx 0.5 - 1 m/s).
• Is the chassis pre-assembled?
  No, this is a DIY kit. Assembly is required and is part of the learning experience. Instructions are generally included or available online.
• Can I convert this to 4-Wheel Steering (4WS)?
  The hardware often permits modification for rear steering if you purchase an additional servo and linkage set, but out-of-the-box it is usually Front-Wheel Steer.
• How much weight can it carry?
  We recommend keeping the payload under 2kg to ensure the steering servo can operate effectively without overheating.
• Do I need a separate battery for the servo?
  Highly recommended. If the servo draws too much current, it can brown out your microcontroller. A shared LiPo with a strong Buck Converter (5V 3A) is best.
• Are the tires soft or hard plastic?
  The kit includes rubber tires with foam inserts or hollow air pockets, providing good traction on carpet and tiles.
• Is this waterproof?
  No. The motors and electronics are exposed. It is for indoor or dry outdoor use only.
• Can I mount a robotic arm on top?
  Yes, the top platform is spacious. However, ensure the arm's weight doesn't compress the suspension/steering too much.
• Does it support Ackerman geometry?
  The linkage is designed to approximate Ackerman geometry, but exact angles depend on your assembly and servo tuning.
• What is the ground clearance?
  Approximately 2-3 cm, suitable for flat surfaces and low obstacles (door thresholds), but not rocky terrain.
• Can I replace the motors with high-RPM ones?
  Yes, the motor mounts generally fit standard "TT" gear motors or "25mm" DC motors. Check dimensions before swapping.
• Why does my robot jitter when steering?
  This usually indicates a weak power supply to the servo. Ensure your power source can deliver at least 2A peak current to the servo.
• Is code provided?
  We provide links to standard libraries and example logic for steering control in our resources section.
• What screws are used?
  The kit mostly uses M3 screws and nuts. A small screwdriver is usually needed.
• Can I use an Arduino Shield?
  Yes, a Motor Shield V1 or V2 is a great way to drive the DC motors and usually has a dedicated 3-pin header for the steering servo.
• Why is one wheel lifting off the ground during turns?
  This chassis is rigid. If the surface is uneven, one wheel might lose contact. Adding a small suspension mechanism or keeping speeds low helps.

• Wheels x4 (Color for Ramdon)
• Motor x1
• Servo x 1
• Switch x 1
• Big Gear x1 (White Plastic)
• Small Gear x1 (White Plastic)
• Sector Metal x 2
• Steering Cup x 2
• Rear wheel link x1
• Metal Chassis x 1
• Acrylic Chassis x 1
• Acrylic Chassis x 1
• Servo Screw Kit x 1
• Anti-collision cotton x1
• Motor mounting bracket x1

• Flange bearing disabilities x2
• Long and short Coupling  x2
• L Mounting bracket x1
• Long Stick 65MMx 1
• Short Stick 48MM x 1
• Transmission Shaft x2
• Big Bearing(12mm) x 2
• Small Bearing (8mm)x 2
• Hexagon adapter x 2
• M2 * 10 Latches x 2
• M3*5mm Screw x 5
• M3 Flat head screw x2
• M3*16mm Copper Column x 4
• M3*22mm Copper Column x 8
• M3*35mm Copper Column x 4