How To Build a Robot

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General Robot Building Questions | The Big Picture

Building your own robot can be a fun and exciting 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. We will go over some robot basics, help you with your part selection, and give you some assembly advice. To get started use our Custom Robot Request Page as a guide with the questions it contains to get a good idea of what kind of robot you want to build. 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? (ie duty cycle)
• Do I want to build using just parts, a kit, or a completely assembled Ready-to-Run (RTR) Robot?

The basics of our robot kits

Our robot kits are designed based on years of experience designing standard and custom robots. All the components are designed to work together. If you do not have much experience building robots, it is best to start with one of our kits. If you go at it from scratch, it can be done, but sizing motors, wheels, batteries, etc. comes from a lot of experience and trial and error. All of our robot kits have options listed at the bottom of the page allowing you to customize the robot. Standard items and options are selected for a default configuration. The options are listed as links and can be clicked to view further details. We offer many different motors, motor controllers, batteries, etc. so you can configure the robot to your exact needs. The weight of the robot, its capacity, speed, etc. depending on how the robot is configured. You will have to click on the option item details to determine weights, sizes, etc.

Most of our robot kits can be purchased in kit form or assembled. Typically, the kits are offered unassembled as an option. If you have never built a robot, done much soldering or mechanical assembly we recommend you opt for us to assemble it for you. Besides the expert assembly, we will 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?

Most of our robot platforms are skid steer robots (left and right wheels are slowed down, stopped or reversed to turn). Since it has to skid to steer, friction is the major contributing factor for sizing your components. The more the robot weighs, the harder it is to turn. The higher the friction coefficient (deep grass, carpet, tracks, etc.), the harder it is to turn. The lower RPM motors have lower speed, but more torque for easier turning. The default options listed for our robot kits are what we recommend as a good starting point. Contact us if you need help selecting options or need custom configuration.

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?

Tracks

Everyone thinks tracks are cool. They are, but they come with complication and price.

Tracks add many advantages:

• Spread your load out for a low PSI rating.
• Makes climbing and bridging over gaps, such as stairs, etc. much easier.
• Handles more aggressive terrain, etc.

They also offer a lot of challenges:

• Less efficient (use more power, larger motors, etc.).
• Components are more expensive.
• Tracking, derailment, tensioning, etc. all must be considered.
• Debris jamming the tracks, etc. needs to be considered.

We offer many pre-made tracks:

• [##CATEGORY161## Treads and Tracks]

We offer many DIY tracks:

• [##CATEGORY162##DIY Tracks and Treads]

And Treaded Robot Kits that are ready to go:

• [##CATEGORY73## Treaded Robot Kits]

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If you are ready to move forward with a tracked robot

You have to consider everything you want out of the chassis, add some room for modification, feature creep, and then add some more. These are things we have learned by building hundreds of custom tracked robot platforms.

Our LT2 and HD2 tracked robot platforms use roller chain to connect the motor to the drive wheel of the tracks. There are other ways of transferring the power from the motor to the ground but for flexibility, durability, and reliability we use roller chain. If you build a robot platform and discover the motors are not powerful enough, too fast, too slow, etc, simply change the number of teeth on your sprockets.

Our LT2 robot, or Light Tank rev2 uses number 25 chain and two IG52 motors, one per track. The 52 means the gearbox is 52 mm in diameter. We power the front two wheels and the back two are idlers. We also offer the LT2-F with flipper arms.

Our HD2 robot, or Heavy Duty Tank rev 2 uses number 35 chain and 4 IG52 motors, one per wheel. All four are driven. They are supported on both sides with roller bearings for a super solid chassis.

Select one of our tracked robot packages:

• [##ITEM2364## SST Robot Platform]. The SST Robot Platform is a smaller version of our [##ITEM1513## LT2] and [##ITEM789## HD2] tanks, but built with the same high level of quality, strength, power, etc.
• [##ITEM1723## MLT-JR Tracked Robot Platform]. Our MLT-JR platform is based on our MLT - Jack Russel Tactical Robot and features the same tracks and similar heavy-duty chassis and drive system. You have your choice of motors, batteries, and controls to get you going!
• [##ITEM2288## MLT-42 Tracked Robot Platform]. This is a MLT-JR tracked robot platform and is equipped with 32mm motors, a motor controller, and Spektrum remote control. This is a rugged robot platform. By default, the treaded robot handles up to 15lbs of additional payload and travels 300ft/min.
• [##ITEM2341## MLT-42-F Tracked Robot Platform]. This is a MLT-42-F tracked robot platform and is equipped with flipper arms, 42mm motors, a motor controller, and Spektrum remote control. This rugged robot platform the treaded robot handles up to 15lbs of additional payload and travels 200ft/min.
• [##ITEM1513## LT2 Tracked ATR Robot Platform]. This platform is a subset of our LT2/LT2-F Bloodhound - Light Surveillance Robot and is one of our NIST qualified tactical robots. The LT2 ATR platform comes standard with the same track system, similar heavy duty aluminum chassis, and your choice of motors, motor controller and batteries.
• [##ITEM1520## LT2-F Tracked ATR Robot Platform]. This is the same package as the LT2 above, but with the addition of a flipper / stabilizer arm that allows the robot to overcome taller obstacles and enables stair climbing.
• [##ITEM789## HD2 Treaded ATR Tank Robot Platform]. Likewise with the MLT-JR and LT2 platforms above, our HD2 platform is a derivative of our HD2-S Doberman - Heavy Duty Surveillance Robot. This powerful treaded kit gives you added ability to haul heavier equipment, scale tougher terrain, and climb stairs without the need of an additional flipper/stabilizer arms.

For more information on tracked robots, see our HD2 Support, LT2 Support, and MLT-JR Support pages.

Wheels

Wheels are by far an easier and less expensive option than tracks.

Wheeled robots have a lot of advantages:

• Easy to use.
• Low maintenance costs.
• Lower cost than tracks.

Some of the disadvantages of wheels:

• High centering when going over uneven terrain.
• Can't climb stairs without making radical suspensions, etc.

We offer many wheel, and wheel and shaft parts:

• [##CATEGORY16## Wheels and Shafts Category]
• [##CATEGORY198## Wheel and Shafts Sets]
• [##CATEGORY153## All Terrain Robot Wheels and Shaft Sets]
• [##CATEGORY156## Omni and Mecanum Wheels and Hubs]
• [##CATEGORY155## Casters]
• [##CATEGORY154## Wheels for Servos and Miniature Wheels]

We also offer ready-made wheeled platforms:

• [##CATEGORY51## Wheeled Robot Platform Kits]

And omni-wheel robot platforms:

• [[##CATEGORY61## Omni Wheel Robot Platform Kits]

To learn more about wheeled robots see our support pages:

• All Terrain Mobile Robots - Help and Information
• Omni-directional 4WD and 3WD Robots

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Wheel Types

Before you decide on the platform, there is another fork in the road with wheeled robots. Do you want to use standard wheels, Omni wheels, or Mecanum wheels?

Standard Wheels:

• Robot Drive Wheel - Traction Lug 13 x 5.00-6 Tiller Tire
• Robot Drive Wheel - Traction Lug 10 x 3.50-4 Tiller Tire
• Robot Drive Wheel - 6 inch pneumatic tire
• Robot Drive Wheel - 10 inch Pneumatic
• All of these wheels can be configured with shaft sets to fit our wheeled robot platforms. Using standard wheels is the simplest method to move your robot.
• See all of our wheel sets here.
• More information can be found on our All Terrain Mobile Robots - Help and Information Support Page.

Omni Wheels - Vectoring:

• Omni Wheels are round wheels with small wheels built into them to allow lateral movement. This feature makes it great for skid steering. There is very little resistance to make a turn, allowing you to load up your robot. The disadvantage to these wheels is that they make a good deal of noise when rolling around, and they are not good for rough or dirty terrain. They will also side slip if put sideways on a hill.
• See all of our omni wheel sets here.
• For more information visit our support pages:
  • Omni-directional 4WD and 3WD Robot Kits.
  • All Terrain Mobile Robots - Help and Information.
  • Vectoring Robots - Help and Information.

Mecanum Wheels:

• Mecanum wheels are round wheels with small wheels/rollers built into them at an angle. This gives the same effect as Omni wheels mounted on angles, only the wheels are pointed straight ahead, making the vectoring and standard driving a lot easier. These wheels have the same downside as Omni wheels in that they cannot handle a dirty environment very well, and they make a fair amount of noise when rolling around.
• See all of our wheel sets here.
• For more information visit our support pages:
  • Mecanum Wheel Robot Kits.
  • All Terrain Mobile Robots - Help and Information.
  • Vectoring Robots - Help and Information.

If you are ready to move forward with standard wheels:

Pictures

Select one of our wheeled robot platform kits:

• [##ITEM2795## WC1000-DM4-E, 4WD All Terrain Robot Enclosed Platform] This is an SDR 4-wheel drive remote control robot kit. It uses four powerful wheelchair motors and 35AH batteries.
• [##ITEM2114## IG32-SB2, 2WD Tube Mount Robot Platform] This robot kit consists of the 2WD robot chassis and provides all the necessary parts to turn the robot chassis into an operational robot. This supports our IG32 planetary gear motors.
• [##ITEM2083## IG42-DB2, 2WD Mobile Robot Platform] This robot kit consists of the 2WD robot chassis and provides all the necessary parts to turn the robot chassis into a operational robot. The chassis will support our IG42 planetary gear motors.
• [##ITEM1930## IG32-DM4, 4WD All Terrain Robot Platform] This Compact 4WD wheeled robot platform is equipped with 32mm motors, a motor controller, and Spektrum remote control. With the default configuration, the robot handles up to 5lbs of additional payload and travels 298 ft/min.
• [##ITEM1648## IG52-DB4, 4WD All Terrain Heavy Duty Robot Platform] This is our Heavy-Duty All-Terrain Robot platform with 52mm gear motors, built to navigate through rough terrain and over small obstructions. This heavy-duty robot is configurable.
• [##ITEM1492## IG42-SB4-E, 4WD All Terrain Enclosed Robot Platform] This 4WD wheeled enclosed robot is equipped with 42mm motors, a motor controller, 10-inch tires, and Spektrum remote control. By default, the robot handles up to 20lbs of additional payload and travels 320 ft/min.
• [##ITEM1478## IG42-DB4-E, 4WD All Terrain Enclosed Heavy Duty Robot Platform] This is our Enclosed Heavy Duty All-Terrain Mobile Robot Platform. Perfect for outdoor mobile surveillance and object detection, this robot is configurable to meet your requirements. This item replaces TP-080-000, TP-081-000, & TP-180-000.
• [##ITEM1477## IG42-DB4, 4WD All Terrain Heavy Duty Robot Platform] This is our Heavy-Duty All-Terrain Robot platform with 42mm gear motors. Built to navigate through rough terrain and over small obstructions, this heavy-duty robot is configurable. This item replaces TP-070-000, TP-071-000, and TP-170-000.
• [##ITEM1474## IG42-SB4, 4WD All Terrain Robot Platform] This 4WD wheeled robot platform is equipped with 42mm motors, a motor controller, and Spektrum remote control. By default, the robot handles up to 25lbs of additional payload and travels 400 ft/min. This robot replaces TP-032-042 and TP-033-042.
• [##ITEM1473## IG32-SB4, 4WD All Terrain Robot Platform] This 4WD wheeled robot platform is equipped with 32mm motors, a motor controller, and Spektrum remote control. By default, the robot handles up to 15lbs of additional payload and travels 300 ft/min. This robot replaces TP-032-032 and TP-033-032.
• [##ITEM2809## IG52-SB4-T, Custom Size 4WD All Terrain Robot] This is 2.5" x 2.5" Aluminum tube with a 1/8" thick wall. We machine it to a custom length. Using two of these you can make your custom-sized robot for IG52 motors.
• [##ITEM2804## IG42-SB4-T, Custom Size 4WD All Terrain Robot] This is 2" x 2" Aluminum tube with a 1/8" thick wall. We machine it to a custom length. Using these you can make your own custom sized robot.

For more information on wheeled robots, see our  All Terrain Mobile Robots - Help and Information.

If you are ready to move forward with vectoring wheels:

Pictures

Select one of our vector wheel robot packages:

• [##ITEM2346## NEW Prebuilt Mecanum Wheel Vectoring Robot] - IG32 SB This is a direct drive 4WD base Programmable robot kit that uses Nexus mecanum wheels and hubs. This robot platform is meant for indoor robotics. It can vector in any direction. It makes a great Autonomous Robot.
• [##ITEM2458## Mecanum Wheel Vectoring Robot Kit - IG42 DB] This is a chain-driven 4WD base robot kit that uses Nexus mecanum wheels and hubs. It can vector in any direction making it a great Autonomous Robot.
• [##ITEM1713## Programmable Mecanum Omni-Directional Vectoring Robot Kit - IG32 SB] This is a robot that utilizes 4 Omni wheels to vector it in any direction. By changing the speeds and directions of the motors the robot can drive in any direction without needing to turn.
• [##ITEM2229## Programmable Tri-Wheel Vectoring Robot Kit - IG32] Medium Duty SB This is a larger IG32 gear motor robot that utilizes three Omni-wheels to vector it in any direction. By changing the speeds and directions of the motors the robot can drive in any direction without needing to turn.
• [##ITEM1788## Programmable Mecanum Wheel Vectoring Robot - IG52 DB] This is a direct drive 4WD base Programmable robot kit that uses Nexus mecanum wheels. It is an Arduino robot platform for indoor robotics. It can vector in any direction. Includes a choice of an authentic Arduino for making a great Autonomous Robot.
• [##ITEM1713## Programmable Mecanum Wheel Vectoring Robot - IG32 SB] This is a direct drive 4WD base Programmable robot kit that uses Nexus mecanum wheels and hubs. The Arduino platform is meant for indoor robotics. It can vector in any direction. Includes the choice of Arduino for making a great Autonomous Robot.
• [##ITEM1487## Programmable Mecanum Wheel Vectoring Robot - IG32 DM] This is a direct drive 4WD base Programmable robot kit that uses Nexus mecanum wheels and hubs. Its an Arduino robot platform for indoor robotics. It can vector in any direction. Includes a choice of an authentic Arduino for making a great Autonomous Robot.
• [##ITEM1486## Programmable Triangular Omni Wheel Vectoring Robot - IG32 DM] This is a programmable triangular Omni vectoring robot platform kit that uses Nexus Omni wheels. It's a great light duty robot kit great for indoor robotics that can vector in any direction. Choice of authentic Arduino for making a great Autonomous Robot.

For more information on vectoring robots, see our  Vectoring Robot Support page.

Motors

You need to gear an electric motor down for the same reason you have a transmission on a car or motorcycle. To get the HP the RPM is typically brought way up, especially in electric motors. If you run it 1 to 1 it will not have enough torque to move, and if it could, it would be way too fast. Take your car, for example. A normal transmission starts in 1st gear, which is the most reduced so you have the low-end torque to start moving, then as you speed up you change gears to get more speed.

With a single speed (an electric bike, golf cart, or robot) you have to find the right balance so you have enough torque to get started from zero speed, but then enough top-end speed. If you gear it down too much you will have plenty of power, but never get any speed. If it's geared too high, you will have trouble getting it started, especially up a hill, etc., but then you will have a fast top end. You need to find a balance where it works well for both. The big electric motors will help because they will muscle through it if you don't have it geared just right, but if it works too hard you will be drawing a ton of current and burning up your batteries!

A few words on motors and axles

Our line of robots are named after the size motor gearbox they use. We offer three basic styles of robots with wheels. We do this to offer different solutions to sideloading the motors.

Motor gearboxes are not specifically designed to support a load. They are designed to rotate a shaft or apply torque. To protect the motor gearbox with heavier loads, the wheel axle should be supported.

• Direct Mount: The wheel and shaft are directly mounted to the motor.
• Single Bearing: The motor is mounted directly to the wheel shaft, but there is an outboard bearing that helps to support the load.
• Double Bearing: This is the most robust configuration. The wheel shaft is supported by the two bearings, and the shaft is chain or belt driven.

For more detailed information on motor mounting, visit our  ATR Support page.

Direct Mount ATR

Some platforms use a chassis with a motor bolted to it and a wheel bolted directly to the motor shaft. This works fine for light loads, our [##ITEM1930## Compact ATR robot] is a perfect example. The durability of the robot platform is directly related to the durability of the motor and gearbox. The more weight you put on the chassis the more the motor has to support.

Single Bearing ATR

For larger loads we have designed a platform that takes the vast majority of the weight off the motor and gearbox by adding a longer shaft and supporting it with an industrial ball bearing. This platform is demonstrated in our [##ITEM1473## IG32] and [##ITEM1474## IG42] ATR examples. The motor is still coupled to the wheel directly just with a longer shaft that runs through a bearing.

Double Bearing ATR

For even larger loads we designed a platform that takes all the load off the motor completely like our [##ITEM1477## Heavy Duty ATR] and [##ITEM1478## Enclosed Heavy Duty ATR]. The wheel is bolted to a high strength axle and that is supported by two industrial-grade ball bearings. Number 25 chain and sprockets connect the motor to the axle. The bearings do what they are designed to do, the motors do what they were designed to do, and the chain and sprockets link them to each other. Together this makes for a truly heavy-duty robot platform.

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So say you want to get 25 mph and you have a 2 ft diameter tire, 25 mph = 25 * 5280 / 60 = 2200 ft/min. For every revolution of the tire: 2 ft * 3.14 you go ~6.25 ft. So you want the tire to rotate at 2200 / 6.25 = 352 RPM. Let's say your motor is 4000 RPM full speed, therefore you need to gear it down by 1:6.25. So if you are using a chain, you put the smallest sprocket on the motor, say 10 teeth (this will be driven by the pitch of the chain and the size of the motor shaft) therefore you will need a 62 tooth sprocket at the wheel.