Build Your Own Antweight Combat Robot: A Step-by-Step Guide
So, you want to build a combat robot? Excellent! Antweight robots (weighing in at 1 pound) are a fantastic entry point into the exciting world of robot combat. They’re small enough to be manageable, affordable to build, and still pack a serious punch. This comprehensive guide will walk you through every step of the process, from initial design to final battle readiness.
## Why Antweights?
Before we dive in, let’s quickly recap why antweights are a great choice for beginners:
* **Affordability:** Components are relatively inexpensive compared to larger weight classes.
* **Manageability:** Their small size makes them easier to transport, store, and work on.
* **Complexity:** They offer a good balance of complexity, allowing you to learn essential robotics principles without being overwhelmed.
* **Durability:** While small, they can withstand significant impacts, making for exciting battles.
* **Community:** A large and supportive community of antweight builders is available to offer advice and assistance.
## The Essential Steps
Here’s a breakdown of the key stages involved in building your antweight combat robot:
1. **Conceptualization & Design:** Defining your robot’s weapon, drive system, and overall strategy.
2. **Component Selection:** Choosing the appropriate motors, batteries, speed controllers, and other necessary parts.
3. **Chassis Construction:** Building the frame that will house and protect your robot’s components.
4. **Wiring & Electronics:** Connecting the various electronic components to power and control your robot.
5. **Weapon Implementation:** Integrating the chosen weapon system and ensuring its proper functionality.
6. **Testing & Refinement:** Rigorously testing your robot’s performance and making necessary adjustments.
## 1. Conceptualization & Design
This is arguably the most crucial stage, as it lays the foundation for your entire build. Consider these factors:
* **Weapon Choice:**
* **Spinners (Vertical or Horizontal):** These are popular due to their high damage potential. They require powerful motors and robust construction.
* **Wedges:** Simple and effective for pushing opponents around. They excel at control and can be surprisingly effective against spinners.
* **Lifters/Flippers:** Use pneumatic or electric actuators to lift or flip opponents. They require careful design to ensure stability.
* **Crushers/Squeezers:** Apply focused pressure to disable or damage opponents. They require strong actuators and a well-designed gripping mechanism.
* **Hammers/Axes:** Deliver a percussive blow. They require a strong striking mechanism and careful balance.
* **Drive System:**
* **Two-Wheel Drive:** Simple and maneuverable, but can be easily immobilized if one wheel loses traction.
* **Four-Wheel Drive:** Offers better traction and stability, but requires more complex wiring and motor control.
* **Tank Drive:** Uses treads instead of wheels, providing excellent traction and maneuverability, especially on uneven surfaces. However, it can be more complex and expensive to implement.
* **Robot Shape & Size:**
* Consider the arena dimensions and potential obstacles. A low-profile design can be effective for getting under opponents.
* Ensure your robot meets the weight limit (1 pound) with all components installed.
* **Strategy:**
* How will your robot approach a fight? Will it be aggressive, defensive, or tactical?
* What are its strengths and weaknesses? How will you exploit your opponent’s vulnerabilities?
**Tools for Design:**
* **Pencil and Paper:** The simplest and most accessible tool for sketching out initial ideas.
* **CAD Software (e.g., Fusion 360, SolidWorks, Tinkercad):** Allows for precise 3D modeling and simulation.
* **Online Robot Design Tools:** Some websites offer specialized tools for designing combat robots, such as those found on Robot Combat communities.
**Example Design:**
Let’s say we’re going to build a simple but effective **horizontal spinner**. Our strategy will be to aggressively attack opponents, using the spinner to inflict maximum damage.
* **Weapon:** Horizontal spinning disc.
* **Drive:** Two-wheel drive.
* **Shape:** Low-profile, rectangular chassis.
## 2. Component Selection
Now that you have a design, it’s time to choose the components that will bring it to life. Here’s a detailed list of the essential parts and factors to consider:
* **Motors (Drive & Weapon):**
* **Type:** DC brushed or brushless motors are common choices.
* **Voltage:** Choose a voltage that matches your battery and speed controllers (typically 7.4V or 11.1V).
* **RPM (Revolutions Per Minute):** Higher RPM means faster movement or spinning speed, but lower torque.
* **Torque:** Higher torque means more power to overcome resistance and push or spin heavy objects.
* **Gearboxes:** Gearboxes increase torque and reduce RPM. Consider using gearboxes to optimize motor performance for your specific application.
* **Selection Criteria:** For drive motors, prioritize torque for pushing power. For weapon motors, prioritize RPM for impact force. Consider the weight and size of the motors as well.
* **Recommended Brands/Suppliers:** FingerTech Robotics, Banebots, Pololu, ServoCity.
* **Batteries:**
* **Type:** Lithium Polymer (LiPo) batteries are popular due to their high energy density and discharge rate.
* **Voltage:** Choose a voltage that matches your motors and speed controllers.
* **Capacity (mAh):** Higher capacity means longer run time.
* **Discharge Rate (C):** Higher discharge rate means the battery can deliver more current to the motors. Ensure the discharge rate is sufficient to power your motors under load.
* **Safety:** LiPo batteries require careful handling and charging. Use a LiPo-specific charger and follow all safety precautions.
* **Recommended Brands/Suppliers:** HobbyKing, Gens Ace, Turnigy.
* **Speed Controllers (ESCs):**
* **Type:** Electronic Speed Controllers (ESCs) regulate the power delivered to the motors.
* **Amperage Rating:** Choose an ESC with an amperage rating that exceeds the maximum current draw of your motors.
* **BEC (Battery Elimination Circuit):** BECs provide a regulated voltage to power the receiver and servos. Some ESCs have built-in BECs.
* **Forward/Reverse:** Ensure the ESC supports forward and reverse operation for drive motors.
* **Braking:** Some ESCs offer braking functionality, which can be useful for stopping quickly.
* **Recommended Brands/Suppliers:** FingerTech Robotics, Scorpion, Castle Creations.
* **Receiver & Transmitter (Radio Control):**
* **Channels:** Choose a receiver and transmitter with enough channels to control all your robot’s functions (drive, weapon, etc.).
* **Range:** Ensure the range is sufficient for the arena size.
* **Protocol:** Common protocols include FHSS and DSM2/DSMX.
* **Recommended Brands/Suppliers:** Spektrum, FrSky, FlySky.
* **Servos (If Needed):**
* **Type:** Standard servos are used for controlling weapon deployment, lifters, or other auxiliary functions.
* **Torque:** Choose a servo with sufficient torque to perform the desired function.
* **Size:** Consider the size and weight of the servo.
* **Recommended Brands/Suppliers:** Hitec, Futaba, Savox.
* **Wheels & Tires:**
* **Material:** Rubber wheels provide good traction. Consider using tires with foam inserts for added grip.
* **Diameter:** Choose a wheel diameter that provides the desired speed and ground clearance.
* **Hub:** Ensure the wheels are compatible with your motor shafts.
* **Recommended Brands/Suppliers:** FingerTech Robotics, Banebots.
* **Chassis Material:**
* **Polycarbonate (Lexan):** Lightweight, durable, and easy to work with.
* **Aluminum:** Stronger than polycarbonate, but heavier and more difficult to machine.
* **Steel:** Very strong and durable, but also very heavy. Typically only used in critical areas.
* **3D Printed Materials (PLA, ABS, PETG):** Can be used for non-structural components, but generally not strong enough for the main chassis.
* **Fasteners:**
* **Screws:** Use machine screws with locking nuts to prevent them from loosening during combat.
* **Threadlocker (Loctite):** Apply threadlocker to screws to further prevent loosening.
* **Rivets:** Can be used for joining sheet metal components.
* **Wiring & Connectors:**
* **Wire Gauge:** Choose a wire gauge that can handle the current draw of your motors.
* **Connectors:** Use reliable connectors to ensure good electrical connections. Common types include XT30, XT60, and JST connectors.
* **Heat Shrink Tubing:** Use heat shrink tubing to insulate connections and prevent short circuits.
* **Safety Equipment:**
* **Safety Glasses:** Protect your eyes from flying debris.
* **Gloves:** Protect your hands from sharp edges and hot components.
* **Fire Extinguisher:** Keep a fire extinguisher nearby in case of battery fires.
**Component List for Our Horizontal Spinner Example:**
* **Drive Motors:** Two FingerTech Robotics Silver Spark motors with 16mm wheels.
* **Weapon Motor:** One FingerTech Robotics Silver Spark motor with a custom-made spinner disc.
* **Battery:** 7.4V 500mAh LiPo battery with a 20C discharge rate.
* **ESCs:** Two FingerTech Robotics TinyESCs for the drive motors and one for the weapon motor.
* **Receiver & Transmitter:** Spektrum DXe transmitter and AR610 receiver.
* **Chassis Material:** 1/8″ polycarbonate (Lexan).
* **Fasteners:** M3 machine screws with locking nuts.
## 3. Chassis Construction
The chassis is the backbone of your robot, providing structural support and protection for the internal components. Here’s how to build it:
* **Cutting the Chassis Components:**
* **Marking:** Use a ruler, calipers, and a marker to accurately mark the dimensions of the chassis components on the chosen material.
* **Cutting Tools:**
* **Polycarbonate:** Use a jigsaw, bandsaw, or rotary tool with a cutting disc.
* **Aluminum:** Use a bandsaw, chop saw, or milling machine.
* **Steel:** Use a plasma cutter, angle grinder, or cutting torch.
* **Safety:** Wear safety glasses and gloves when using power tools.
* **Assembling the Chassis:**
* **Joining Methods:**
* **Screws:** The most common method for joining chassis components. Drill pilot holes and use machine screws with locking nuts.
* **Rivets:** Can be used for joining sheet metal components.
* **Welding:** Provides a strong and permanent bond, but requires specialized equipment and skills.
* **Adhesives:** Can be used for bonding certain materials, but may not be strong enough for high-stress areas.
* **Alignment:** Ensure the chassis components are properly aligned before fastening them together.
* **Reinforcement:** Add gussets or braces to reinforce weak areas of the chassis.
* **Mounting Components:**
* **Motor Mounts:** Design and fabricate motor mounts to securely attach the motors to the chassis. Consider using vibration-dampening mounts to reduce noise and vibration.
* **Battery Mount:** Create a secure battery mount to prevent the battery from shifting during combat.
* **ESC Mounts:** Mount the ESCs in a location that allows for good airflow and easy access.
* **Receiver Mount:** Mount the receiver in a location that is protected from impact and interference.
* **Tips for a Strong Chassis:**
* **Box Structure:** A box-shaped chassis is generally stronger than a flat plate chassis.
* **Rounded Corners:** Rounded corners are less likely to crack or break than sharp corners.
* **Stress Relief:** Avoid sharp transitions in thickness or shape, as these can create stress concentrations.
**Chassis Construction for Our Horizontal Spinner Example:**
1. **Cut:** Cut six pieces of 1/8″ polycarbonate to form a rectangular box. The dimensions will depend on the size of the components and desired overall size of the robot.
2. **Assemble:** Use M3 machine screws and locking nuts to assemble the box. Reinforce the corners with small aluminum angle brackets.
3. **Motor Mounts:** 3D print or fabricate aluminum motor mounts for the drive motors. Attach the mounts to the inside of the chassis.
4. **Weapon Mount:** Create a sturdy mount for the weapon motor, ensuring it is securely attached to the chassis and can withstand the forces generated by the spinning disc.
5. **Battery Mount:** Use Velcro straps to secure the battery to the floor of the chassis.
## 4. Wiring & Electronics
This is where you connect all the electronic components to power and control your robot. Careful wiring is essential for reliable performance and safety.
* **Wiring Diagram:**
* Create a detailed wiring diagram before you start wiring. This will help you avoid mistakes and ensure that everything is connected correctly.
* **Soldering:**
* Learn how to solder properly. Good solder joints are essential for reliable electrical connections.
* Use a soldering iron with adjustable temperature control.
* Use flux to promote good solder flow.
* Inspect solder joints carefully to ensure they are smooth and shiny.
* **Wire Management:**
* Use zip ties or cable sleeves to keep wires organized and prevent them from getting tangled or damaged.
* Route wires away from moving parts to prevent them from being snagged or cut.
* **Connector Installation:**
* Crimping: Use a crimping tool to securely attach connectors to wires.
* Soldering: Solder the wires to the connector pins for added reliability.
* Heat Shrink: Use heat shrink tubing to insulate the connections and prevent short circuits.
* **Testing:**
* Test each connection with a multimeter to ensure continuity and proper voltage levels.
* Test the entire system before installing it in the chassis.
* **Safety Precautions:**
* Disconnect the battery before working on the wiring.
* Avoid short circuits. Short circuits can damage components and cause fires.
* Use insulated tools to prevent shocks.
**Wiring Diagram for Our Horizontal Spinner Example:**
1. **Battery to ESCs:** Connect the battery to the ESCs using XT30 connectors. Ensure proper polarity (red to positive, black to negative).
2. **ESCs to Motors:** Connect the ESCs to the drive motors and weapon motor. Pay attention to the motor polarity for forward/reverse control.
3. **ESCs to Receiver:** Connect the signal wires from the ESCs to the appropriate channels on the receiver.
4. **Receiver Power:** Connect the BEC output from one of the ESCs (or a separate BEC) to the receiver power input.
## 5. Weapon Implementation
The weapon is the heart of your combat robot. Here’s how to integrate it effectively:
* **Mounting the Weapon:**
* **Secure Attachment:** Ensure the weapon is securely attached to the chassis and can withstand the forces generated during combat.
* **Alignment:** Properly align the weapon to ensure it functions correctly.
* **Balance:** Balance the weapon to prevent excessive vibration.
* **Weapon Motor Control:**
* **Speed Control:** Use an ESC to control the speed of the weapon motor.
* **Direction Control:** Consider adding a reversing switch to change the direction of the weapon.
* **Safety Switch:** Implement a safety switch that disables the weapon when the robot is not in the arena.
* **Weapon Safety:**
* **Shielding:** Shield the weapon to prevent it from damaging the robot itself or other components.
* **Locking Mechanism:** Implement a locking mechanism to prevent the weapon from spinning accidentally.
* **Testing:** Thoroughly test the weapon before using it in combat.
**Weapon Implementation for Our Horizontal Spinner Example:**
1. **Spinner Disc:** Fabricate a spinner disc from AR500 steel or a similar durable material. Ensure the disc is properly balanced.
2. **Motor Mount:** Attach the weapon motor to the motor mount, ensuring it is securely fastened.
3. **Disc Attachment:** Attach the spinner disc to the motor shaft using a collet or a similar locking mechanism.
4. **Shielding:** Add a polycarbonate shield around the spinner disc to prevent it from damaging the robot’s chassis.
5. **Testing:** Test the spinner at various speeds to ensure it is properly balanced and does not vibrate excessively.
## 6. Testing & Refinement
Testing is crucial for identifying and correcting any problems with your robot before you enter the arena. Refinement involves making adjustments to improve performance.
* **Drive Testing:**
* **Maneuverability:** Test the robot’s maneuverability in a confined space. Can it turn easily? Can it navigate obstacles?
* **Speed:** Test the robot’s speed on a flat surface. Is it fast enough to compete effectively?
* **Traction:** Test the robot’s traction on different surfaces. Does it have enough grip?
* **Weapon Testing:**
* **Spin-Up Time:** Measure the time it takes for the weapon to reach full speed. Is it fast enough?
* **Impact Testing:** Test the weapon’s impact force by striking a stationary object.
* **Durability Testing:** Test the weapon’s durability by running it at full speed for an extended period of time.
* **Battery Life Testing:**
* Measure the battery life under normal operating conditions. Is it sufficient for a typical combat round?
* **Stress Testing:**
* Subject the robot to various stresses, such as impacts, drops, and vibrations. Look for any signs of damage or weakness.
* **Refinement:**
* **Adjust Motor Speeds:** Adjust the motor speeds to optimize performance.
* **Fine-Tune Weapon Balance:** Fine-tune the weapon balance to reduce vibration.
* **Improve Traction:** Experiment with different tires or wheel configurations to improve traction.
* **Strengthen Weak Areas:** Reinforce any weak areas of the chassis.
**Troubleshooting Tips:**
* **Robot Won’t Turn On:** Check the battery voltage, wiring connections, and ESC settings.
* **Motors Don’t Spin:** Check the motor connections, ESC settings, and receiver signal.
* **Weapon Doesn’t Work:** Check the weapon motor connections, ESC settings, and safety switch.
* **Robot Loses Control:** Check the receiver signal, battery voltage, and wiring connections.
## Safety First!
Robot combat is a potentially dangerous activity. Always follow these safety precautions:
* **Wear safety glasses and gloves.**
* **Keep a fire extinguisher nearby.**
* **Never operate your robot without proper supervision.**
* **Follow all rules and regulations of the combat event.**
* **Handle LiPo batteries with care.**
## Where to Compete
Once your robot is complete, you’ll want to test it out in a real competition. Here are some resources for finding combat robot events:
* **Robot Combat Organizations:** Check the websites of major robot combat organizations like Robot Fighting League (RFL) and SPARC (Sporting Pit Association of Robot Combat).
* **Online Forums & Communities:** Participate in online forums and communities dedicated to robot combat. These forums often have announcements about upcoming events.
* **Local Maker Spaces:** Many maker spaces host robot combat events.
## Beyond the Basics
Once you’ve mastered the basics of building an antweight robot, you can start experimenting with more advanced techniques:
* **Advanced Materials:** Explore the use of advanced materials like carbon fiber and titanium to reduce weight and increase strength.
* **Custom Electronics:** Design and build your own custom ESCs and motor controllers.
* **Artificial Intelligence:** Incorporate AI algorithms to automate robot behavior.
* **Pneumatics & Hydraulics:** Use pneumatics and hydraulics to power lifters, flippers, and crushers.
## Conclusion
Building an antweight combat robot is a challenging but rewarding experience. By following the steps outlined in this guide, you can create a competitive robot that will bring you hours of enjoyment. Remember to be creative, have fun, and always prioritize safety. Good luck, and may the best robot win!