How To Build a Robot

General Robot Building Questions | The Big Picture

Building your own robot can be a fun and instructional experience. It can be a little frustrating though when you are not sure about a certain aspect of the build. This is a step by step guide that will help you get your robot up and running. In this guide we will go over some robot basics, help you with part selection, and give some assembly advice. To get started you can use answer some of the questions on our Custom Robot Request Page. These will help you figure out the type of robot you want to build and help a little with part selection. You may also submit the form if you would like to skip the DIY and have SuperDroid Robots and its professional staff build it for you.

Some questions you will want to ask yourself

• What is my budget?
• What is my schedule?
• What do I want the robot to do?
• What type of terrain will it be used on?
• Do I have any size requirements or restrictions?
• Do I have any weight requirements or restrictions?
• Do I want it to be weather resistant? Weatherproof? Waterproof?
• Do I have any additional capacity requirements for volume and/or weight?
• How do I want to control it? Wireless, tethered, Autonomous, RC, WiFi, Fiber Optics, IR, etc.
• How long of a run time will I need? Will it be run continuously or intermittently during this time? (i.e. what is the required duty cycle?)
• Do I want to build using just parts, a kit, or a completely assembled ready-to-run robot?

The basics of our robot kits

Our robot kits are developed based on years of experience designing custom robots. All the components are designed to work together. If you do not have much experience building robots, the easiest thing to do will be to start with one of our robot kits. If you start from scratch you'll have to make a lot of decisions about size/speed of motors, size and type of wheels, type and capacity of batteries, and many more. Making these decisions can require experience and some trial and error. With our robot kits, we have made many of these decisions already and taken most of the guesswork out of the equation. All of our robot kits have options listed at the bottom of the page allowing you to configure the robot with parts that will work together.

Most of our robot kits can be purchased in kit form (unassembled) or assembled. If you have never built a robot or you do not have much experience with soldering and mechanical assembly, we recommend you opt for us to assemble it for you. We will have our experienced technicians assemble and test it. If anything is not right (such as a defective motor or motor controller, battery charger, etc.) we will replace it and make sure everything is ready to run when you receive it.

How does a robot turn?

Skid Steer versus Conventional Steering

Let's Get Started!

There are a lot of decisions that need to be made once the general questions are answered. Most of this information is in order. In some cases you can jump around, but basically you cant pick your batteries, until you know what your motors are, and you cant pick motors until you pick a platform, etc.

Tracks or Wheels?

The start of the project requires you to make a big decision, do you want tracks or wheels? Read the discussions below to help you make the right decision for your needs and your budget.

Robot Tracks

Robot Wheels

Motors, Axles, and Speed

Motors

A discussion of motors can be found here.

Axles (AKA Wheel Shafts)

Follow the discussion here for Wheel Shafts

Robot Speed Calculator

This is a helpful tool to figure out the speed of your robot. Input the RPM your motor, any chain reduction (if direct drive use 1), and the outside diameter your wheel or track.

The Robot Speed Calculator has been moved here.

Motor Controllers

Motor Controllers

Motor Controllers take signals from a microprocessor or radio control receiver and convert it into a high current varying voltage. Motor controllers are rated based on the voltage and current requirements. You can take a look at some of our robot kits to get an idea of what size motor controller you will need. We carry RoboteQ motor controllers, which will take encoder inputs for speed and/or position control, as well as Dimension Engineering's Sabertooth with a Kangaroo for encoder input.

For more help with using encoders with motor controllers:
Motor Controller Support Page, and our  
Encoder Support Page.

Robot Batteries

When selecting the appropriate batteries for your robot, you need to size them by voltage to match the desired motors and motor controller. You will also need to take into consideration the maximum current output and the battery type and capacity.

Discussion of Batteries is found here.

Robot Controller

There are several options for controlling your robot. The big division of remote control is between Analog versus Digital Control.

Click to read more about Robot Control Systems.

Wiring

Power and Battery Wiring

When wiring your batteries to your robot there are concerns you must address. Namely, what output voltage do you need and how you are going to charge the batteries. When using two 12V batteries you will need to wire them in parallel to power 12V motors and in series to power 24V motors.

The key things to consider are what voltages do you need and how much power The driving force for the main battery will be the motors. We typically use 24VDC motors, they run at half the current for the same power as 12V motors so smaller wires, motor controllers, etc. Do you need a separate battery for the controller or on-board computer, etc? How are you going to get those voltages (multiple batteries, voltage regulators, etc.)? How much of a load will be on each voltage so your batteries and/or regulators are sized properly? This will help you size your batteries: simple math. If you have a 1Amp load and a 10Ahr (10,000mAhr) battery, the battery will run for 10 hours in theory.

For more help with wiring, please visit our Robot Wiring Support Page.

Motor Wiring

Generally motors are wired to a motor controller to provide speed control to motors. The motor controller can be used to change the directions of the motor as well. If running motors in parallel (as in a 4WD the two left and the two right motors will be running together in parallel) you can wire them in parallel too.

We have a lot of information on how to wire motors, etc. on our Motor Wiring Support Page.

 For more help with wiring, please visit our Motor Wiring Support Page.

Sensors

We offer a wide range of sensors. The more sensors used, the better the autonomy will be. Relying on only one type of sensor for all your positioning will work for simple situations, but will probably cause issues for any complex positioning or for any positioning that requires higher precision.

In robotics, sensors can be used to monitor your environment or to determine your robot's position relative to some object. Standard sensors for environment monitoring can range from temperature thermocouples, gas, and radiation. The standard positioning sensors are Sonic and IR for object detection and GPS, gyroscopes, and accelerometers to determine relative location, direction, and airspeed. For ground travel and RPM feedback, a combination of our encoder enabled motors and our encoder buffer board make it incredibly easy to implement your own speed control algorithms and RPM feedback. The encoder can also be used to keep track of the distance traveled, but with skid steer the more you turn/skid the more inaccurate the reading because of the wheel slips/skids resulting in encoder counts, but no relative movement.

• For a complete list of our available sensors, please visit this link (LINK: cat 57).
• Accelerometers, Gyros, GPS, & Compasses: Accelerometers, Gyros, GPS, & Compasses. Measure acceleration and track rotation with these accelerometers, gyroscopes, compasses/magnetometers, and combined inertial measurement units (IMUs) and orientation sensors.
• Contact Sensors: Contact Sensors. Switches and Bumper Switches used to indicated when a physical limit has been reached.
• Current Sensors: An assortment of unidirectional and bidirectional Hall effect-based current sensors. They offer a very low-resistance current path and electrical isolation between the current source and the measuring circuit.
• Force Sensors: Force-sensing resistors (FSRs) are passive components that exhibits a decrease in resistance when there is an increase in the force applied to the sensor allowing you to create a sensor that is able to detect force or pressure.
• Gas Sensors: Gas sensors makes it possible to measure concentrations of gasses such as alcohol, methane, propane, butane, and carbon monoxide.
• Magnetic Guide Sensors: Precision magnetic sensor for detecting and measuring the position of a magnetic track along the horizontal axis, for use in Automatic Guided Vehicles and other Automation applications.
• Optical Sensors - IR, PIR, Photo, & Lasers: Optical IR Sensors & Laser Range Finders. IR distance sensors make it easy to detect and range objects. The laser range-finder is inexpensive, accurate and easy to use with a 240 degrees scan area.
• Sonar Range Finders: Accurately measure distances over a wide range with our assortment of ultrasonic distance sensors from Maxbotix and Devantech.
• Temperature and Humidity Sensors: These sensors measure the humidity of the air and can measure the temperature. Great features for your microcontroller project.

 For more detailed information on sensors, visit our  Sensor Support page.