Step 8: Wiring and controls
A robot without controls is just a piece of art. You will need some way to control each one of your motors or sub systems remotely so that you can safely be outside of the area and still enjoy the fruits of your labors.
The control systems from robot to robot can be very differently based on the style that the builder chooses. Some builders prefer to use a mirocontroller ( a small computer) to program their bots for special functionality or to make them easier to drive. The most common method for combat is to use a Radio Control system similar to that used in model airplanes or cars.
The basics of the system is that your radio system comes with a receiver with different outputs or channels, connected to each one of these ports is a speed controller. The speed controller is necessary so that each motor can have proportional control. You can read more about their purpose and function here http://en.wikipedia.org/wiki/Electronic_speed_control
The wiring connections are outlined in the photo below. Each motor is connected to it's own speed controller, which is connected to a power source through a switch or breakout board. The speed controllers also receive a signal in the form of PWM (Pulse Width Modulation). This signal gets interpreted in the speed controller which provides a correct voltage to the motor. For a live wiring example you can view a labeled photo here http://www.warbotsxtreme.com/basicelect.htm
Not all speed controllers are are created equal, there are many different voltage and amperage ratings make sure that the ones you get match the motors that you choose. The price for controllers is directly related to the amount of amperage they can handle. There are numerous companies that make speed controllers which would be appropriate. For all of my robots I use the Innovation First Victor line of controllers http://www.innovationfirst.com. They are one of the top selling controllers of all time and are built like a rock. The http://www.robotmarketplace.com has a good assortment of motor controllers, but since I don't have experience with others I suggest checking out some other reviews, especially for very small ones
When choosing a radio system you will have a choice these days between PPM (FM), PCM, 2.4 GHZ, 800MHZ, and 802.11 Each one of these has it's advantages and changes the price of the system.
PPM (FM) - one of the oldest forms and the cheapest you can get a complete setup for under $50. These tend to be really bad with interference and they are regulated by the FCC.There are different frequencies are made for Ground use and some are for Air. Make sure to get one for ground use as it is illegal to use one for air.
PCM - Is a system similar to PPM except there are systems in place to link your transmitter and receiver which minimizes interference. These still fall under FCC regulations.
2.4 GHZ - is the same frequency as many household phones. It is a real digital system which will not allow any interference once the receiver is paired with the controller. This is the most common system in place now and what I use for my small battle bot (spektrum D6). These systems run ~$300 but once you own it you can use it time and time again.
800MHZ - the Innovation First micro controller system uses an 800MHZ system. This allows for programming of advanced functionality. These systems cost upwards of $1200 and are mostly used for larger robots. If you can afford one I recommend it. I use this system on my Heavyweight robot (220lbs)
There are many types of batteries available for combat robots. Small robots commonly use LiPoly batteries, which have the advantage of being long lasting and powerful with minimal weight. These packs are beginning to come down in price but are still more expensive than other options.
Medium bots use NiCad packs, similar to those found in drill batteries. These packs are proven systems and relatively cheap. You can get battery packs premade in many different sizes, shapes, and configurations. Many companies online allow people to customize their packs and build them to order. I recommend http://www.battlepacks.com for custom packs of this type
Larger robots tend to use Sealed Lead Acid batteries or NiCad packs. SLA batteries are cheap and easy to come by. They are designed to be mounted in any configuration and come in many sizes. Unfortunately they tend to be heavier than their NiCad counterparts.
Batteries for me are the last thing I choose since there are so many options. I calculate the amount of power I will use during the match and find the battery pack which has the right about of capacity and fits the spacial profile for the robot. Recently I have gotten a hold of some new lithium batteries which I will be experimenting with for future machines.
The control systems from robot to robot can be very differently based on the style that the builder chooses. Some builders prefer to use a mirocontroller ( a small computer) to program their bots for special functionality or to make them easier to drive. The most common method for combat is to use a Radio Control system similar to that used in model airplanes or cars.
The basics of the system is that your radio system comes with a receiver with different outputs or channels, connected to each one of these ports is a speed controller. The speed controller is necessary so that each motor can have proportional control. You can read more about their purpose and function here http://en.wikipedia.org/wiki/Electronic_speed_control
The wiring connections are outlined in the photo below. Each motor is connected to it's own speed controller, which is connected to a power source through a switch or breakout board. The speed controllers also receive a signal in the form of PWM (Pulse Width Modulation). This signal gets interpreted in the speed controller which provides a correct voltage to the motor. For a live wiring example you can view a labeled photo here http://www.warbotsxtreme.com/basicelect.htm
Not all speed controllers are are created equal, there are many different voltage and amperage ratings make sure that the ones you get match the motors that you choose. The price for controllers is directly related to the amount of amperage they can handle. There are numerous companies that make speed controllers which would be appropriate. For all of my robots I use the Innovation First Victor line of controllers http://www.innovationfirst.com. They are one of the top selling controllers of all time and are built like a rock. The http://www.robotmarketplace.com has a good assortment of motor controllers, but since I don't have experience with others I suggest checking out some other reviews, especially for very small ones
When choosing a radio system you will have a choice these days between PPM (FM), PCM, 2.4 GHZ, 800MHZ, and 802.11 Each one of these has it's advantages and changes the price of the system.
PPM (FM) - one of the oldest forms and the cheapest you can get a complete setup for under $50. These tend to be really bad with interference and they are regulated by the FCC.There are different frequencies are made for Ground use and some are for Air. Make sure to get one for ground use as it is illegal to use one for air.
PCM - Is a system similar to PPM except there are systems in place to link your transmitter and receiver which minimizes interference. These still fall under FCC regulations.
2.4 GHZ - is the same frequency as many household phones. It is a real digital system which will not allow any interference once the receiver is paired with the controller. This is the most common system in place now and what I use for my small battle bot (spektrum D6). These systems run ~$300 but once you own it you can use it time and time again.
800MHZ - the Innovation First micro controller system uses an 800MHZ system. This allows for programming of advanced functionality. These systems cost upwards of $1200 and are mostly used for larger robots. If you can afford one I recommend it. I use this system on my Heavyweight robot (220lbs)
There are many types of batteries available for combat robots. Small robots commonly use LiPoly batteries, which have the advantage of being long lasting and powerful with minimal weight. These packs are beginning to come down in price but are still more expensive than other options.
Medium bots use NiCad packs, similar to those found in drill batteries. These packs are proven systems and relatively cheap. You can get battery packs premade in many different sizes, shapes, and configurations. Many companies online allow people to customize their packs and build them to order. I recommend http://www.battlepacks.com for custom packs of this type
Larger robots tend to use Sealed Lead Acid batteries or NiCad packs. SLA batteries are cheap and easy to come by. They are designed to be mounted in any configuration and come in many sizes. Unfortunately they tend to be heavier than their NiCad counterparts.
Batteries for me are the last thing I choose since there are so many options. I calculate the amount of power I will use during the match and find the battery pack which has the right about of capacity and fits the spacial profile for the robot. Recently I have gotten a hold of some new lithium batteries which I will be experimenting with for future machines.
Step 9: Testing and tweeking
Now that you have your robot mostly put together and wired you have reached the really fun part. TESTING.
When doing this make sure you are properly protected and safe depending on the size of your robot and the weapons your robot may be lethal if not controlled properly.
I like to test the subsystems separately before I test the bot all together. That way I can analyze problems to each component before having to backtrack the entire machine to find problems.
Once your robot is complete make sure to drive your robot, getting a feel for the controls, many matches have been won or lost just because of driving skill. The more you test before your competition the better prepared you will be. I try to break my robots before the event as I would rather figure out mistakes and fix problems when I have time to fix them rather than the time in between the match.
Another advantage to running your machine is "break in period" Every new gearbox or mechanical component will have to wear in a bit and will loosen up. You want to try and get everything broken in before your first competition so you are not dealing with changing robot conditions throughout the day.
Ultimately It is important to remember that Design is an iterative process. You will never get it right the first time but with testing and modifications you can make it work.
When doing this make sure you are properly protected and safe depending on the size of your robot and the weapons your robot may be lethal if not controlled properly.
I like to test the subsystems separately before I test the bot all together. That way I can analyze problems to each component before having to backtrack the entire machine to find problems.
Once your robot is complete make sure to drive your robot, getting a feel for the controls, many matches have been won or lost just because of driving skill. The more you test before your competition the better prepared you will be. I try to break my robots before the event as I would rather figure out mistakes and fix problems when I have time to fix them rather than the time in between the match.
Another advantage to running your machine is "break in period" Every new gearbox or mechanical component will have to wear in a bit and will loosen up. You want to try and get everything broken in before your first competition so you are not dealing with changing robot conditions throughout the day.
Ultimately It is important to remember that Design is an iterative process. You will never get it right the first time but with testing and modifications you can make it work.
Step 10: Enjoy your robot
Now that you have built a robot make sure to have fun with it. Take it to competition and try to do your best, remember that it isn't necessary that you win every match or event as building the machine is 75%+ the fun of the project. Every robot you build will be a little bit better than the last, and use them to improve your skills as a designer and engineer.
I hope you found this instructable both helpful and informative. Below are a bunch of other resources for bot building.
Forum for combat robotics: http://forums.delphiforums.com/THERFL/
Http://www.botcentric.com - my new robotics video show, much more diy content and news (coming soon)
Sources of parts and supplies :
AndyMark.biz - mechanical components
Banebots.com - motors, wheels, and components
Robotmarketplace - everything you need
Yarde Metals - metal suplus
onlinemetals.com - huge assortment of metal
B.G. Micro - Surplus Electonics, etc.
SDP-SI - drive componets
C&H - Surplus Electronics and mechanical
Alltronics - Surplus Electronics, etc.
All Electronics - Surplus Electronics, etc.
Northern Tool - Tools, wheels, chain transmission components
Grainger - Industrial Supply
McMaster-Carr - Industrial Supply
WM Berg - Precision Gear Products
American Science & Surplus - Surplus motors, batteries, gears, pulleys, and ?
Industrial Metal Supply - Great deals on remains stock and Steel and Al by the pound.
Team Delta Engineering - RC Interfaces, Motors and other combat specific robot parts
RobotBooks.com - Great collection of robot and electronic guidebook, fiction, toys, etc.
I hope you found this instructable both helpful and informative. Below are a bunch of other resources for bot building.
Forum for combat robotics: http://forums.delphiforums.com/THERFL/
Http://www.botcentric.com - my new robotics video show, much more diy content and news (coming soon)
Sources of parts and supplies :
AndyMark.biz - mechanical components
Banebots.com - motors, wheels, and components
Robotmarketplace - everything you need
Yarde Metals - metal suplus
onlinemetals.com - huge assortment of metal
B.G. Micro - Surplus Electonics, etc.
SDP-SI - drive componets
C&H - Surplus Electronics and mechanical
Alltronics - Surplus Electronics, etc.
All Electronics - Surplus Electronics, etc.
Northern Tool - Tools, wheels, chain transmission components
Grainger - Industrial Supply
McMaster-Carr - Industrial Supply
WM Berg - Precision Gear Products
American Science & Surplus - Surplus motors, batteries, gears, pulleys, and ?
Industrial Metal Supply - Great deals on remains stock and Steel and Al by the pound.
Team Delta Engineering - RC Interfaces, Motors and other combat specific robot parts
RobotBooks.com - Great collection of robot and electronic guidebook, fiction, toys, etc.
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