What Kind of Robot Should I Build?
Building a robot is one of the most wonderful and one of the most frustrating endeavors you can do. While it’s always glorious and wonderful to make something, it’s especially wonderful when the thing that you made actually moves and does all the things that you’ve dreamed it would. It’s also a journey filled with changes and things not working out the way you intended.
This isn’t a “how-to build a robot” article. It’s a “how to decide what kind of robot to build” article. There are literally thousands of choices out there, so you’ll need a starting point in figuring out which should be your first robot.
When building your first robot, one of the best starting points is a complete kit such as those sold by fingertechrobotics.com, trossenrobotics.com, or legoeducation.us. While assembling a kit isn’t as glamorous as building a robot from scratch, there’s a lot to learn on your first robot, and kits make things a lot easier for you. You will learn much more about robotics by building a robot from scratch, but there’s so much to grasp that most people do better starting with a kit, and then moving on to a scratch built bot.
In ensuring that you finish your robot, one of the best things that you can do for yourself is to build a robot for a public competition. Some events include combat, sumo, LEGO Mindstorms, maze solving, and bartending. The primary reason for building for a competition? It gives you a deadline. Consider all the wonderful things built for RoboGames or Maker Faire. If you ask around, a great number of those projects weren’t completed until a week before the event. Now I know that you’re not one of those people who procrastinate, but for those other who do, signing up for an event helps to make sure everything stays on time.
Another great thing about going to a competition is the great people that you’ll meet. They’ve all build a robot similar to yours, so right away you have something in common. They’ll also be flush with ideas and different backgrounds on how they built their robots, so you’ll be able to help each other to improve the robots that you’ve built.
There are scores of competitions around the country (and the world) at all times of the year. Most mini-Maker Faires have robot competitions or exhibits, and big cities such as Seatlle, Dallas, Kansas City, San Jose, Miami, and Pittsburgh often have annual events at museums or full venues. The best place to find competitions local to your area is http://robots.net/rcfaq.html
Building Your First Robot
The first thing you need to decide on is whether to build a programmable autonomous robot or a remotely operated robot (ROV). Actually building something that can move and steer reliably is harder than you might think, so building an ROV is a great way to get used to the mechanical aspects involved (such as making sure that your motors don’t pull off your frame, or that your frame doesn’t pull itself apart if it goes too fast or hits a wall.)
The most fundamental aspect of a robot is a motor. Whether the robot is autonomous or remotely operated, it has to move. Realistically, the minimum number of motors is two – a left wheel and a right wheel. Actually getting motors to work consistently with varying speeds can be shockingly difficult once you get down to it. Robots don’t steer like cars do by changing the angle of the front wheels, they move by changing the speeds of the opposing wheels (often called skid- or tank-steering).
Pro-Tip: If you’re building an ROV, make sure that you use a 2.4 GHz R/C unit or similar, that has digitally mated transmitter and receiver pairs. You want to be sure that no other transmitter can control your robot and that your transmitter doesn’t end up driving someone else robot, plane, or car (this can happen with 75 MHz systems).
If you’d like to play more on the programming side of the fence, then LEGO Mindstorms is a good way to go (full disclosure: I am a full time LEGO employee). The retail version is more based on remote control operation. If you’ve never programmed anything before, Mindstorms is a great introduction to programming as it’s all graphically oriented (like icons on a iPad) but includes all the fundamentals of programming – loops, arrays, variables, etc.
Pro-Tip: The LEGO Education version of the EV3 includes 48 lessons about how to move the robot and use the built in sensors.
If you want to get into the nitty-gritty of electronics, then consider a Parallax Basic stamp or Arduino board. These let you add pretty much any type of component you want, and build robots with 16 or more different inputs and outputs. But with all that ability, comes complexity. If it were easy to make a robot do the mambo, everyone would be doing it.
Pro-Tip: Don’t just get a board. Make sure you get a project book that guides you through all the steps of electronics and programming.
If you’re going to build a remote controlled combat robot or sumo robot, remember that there are weight classes just like in boxing. Robots need to be under a pre-specified weight class (in combat it’s 1, 3, 30, 60, 120 or 220-pounds) and robots that come in over-weight aren’t allowed to compete. Working within specifications actually makes you a better robot builder. By being forced to compromise or modify, you learn a lot about what’s mechanically feasible and what’s not.
Don’t Give Up
The most important part of building robots – like anything you’re making from scratch – is to not get frustrated. If robots were easy, we’d all have a C-3PO at home to bring us our morning tea. The reason we don’t is because robotics is hard. When you get into humanoids, there are as many as 18 motors involved – all of which need to have precise positioning at all times, which is why it’s best to start with a two wheeled robot.
So pick a robot, set a date to finish, and get started! It can be really hard to not put things off until “next weekend” so stick to a schedule and promise yourself that you’ll put in 3 hours every week as if it were a real job.
This week marks the official launch of Make: Volume 39 — Robotics, which drops on newsstands the 27th. Be sure to grab a copy at a retailer near you, or subscribe online right now and never miss another issue.
We are celebrating with five days of robot-related articles, pictures, videos, reviews and projects. Tune into this space for Robot Week!