Today is the first day of the FIRST Championship, a culmination of the season’s FIRST programs, including the FIRST Robotics Competition (FRC) Championship, the FIRST Tech Challenge (FTC) World Championship, and the FIRST LEGO League (FLL) World Festival.
We worked with one of the competing teams – FTC Team 3113: Some Disassembly Required – who has seen a great deal of success already this competition season. They were:
- Ranked 8th in the FTC East Division
- Selected as the 2nd place Inspire award winner at the East Super regional
- Won the Delaware State Championship
- Awarded the Inspire Award at the Delaware State Championship
Nearly 30 percent of the FTC Team 3113’s robot was 3D printed, and we supplied our printing services to help the team print a battery hold, flat bracket, goal capture and motor mount out of ABS plastic on a Stratasys Dimension 768 SST for the final robot.
We asked the team to share their experiences designing, building and competing in this two-part blog series.
Today we hear how 3D printing and rapid prototyping played a role in the design process.
Congrats on all of your success! Can you give us a brief overview of your robot – the problem you’re looking to solve, how you went about building your robot, and the overall outcome of all your hard work?
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FIRST Robotics posts a new challenge to the teams every season. This season, the challenge is called “Cascade Effect”. The objective of the game is to put as many wiffle balls in the rolling goals which are spread around the field. The goals, which are essentially tall transparent tubes atop a rolling platform, measure in heights from 10-48 inches, and can only be touched by the robot at the base of the tube.
The biggest constraint to the robots design being that it must fit within an 18x18x18 inch box at the start of the match, but then extend somehow to the required height. Also on the field is a ramp that the robot can drive up on, and a mechanism in the center of the field that robots can use to release the balls that will be used to score. This release is called a “Cascade”.
The game is played like any other sport, with a field, two alliances, and a score to determine the winner. At the start of the 2 minute 30 second match, the robots function autonomously and attempt to score in the various goals. During the next 2 minutes of the match, teams control their robot with a remote, and can continue to attempt to score as many points as possible.
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Matches are played with 4 teams, of which are constructed into two randomly arranged alliances. The robots must not only be able to score as many points as possible, but work well enough that they can function on their own in a crowded, busy competition field.
We use an engineering design process like any other design project would. To begin, we identify our problem, and brainstorm a solution. At the start of this season, all of our 13 members met and discussed possible ways to collect and dispense balls into the goals. We had various ideas including arms, elevator lifts, and even shooting mechanisms. We continue this path by sketching and CAD modeling our ideas. This helps us plan how we are going to construct our design, what parts will be needed, and determine how it will fit into our robot. After breaking into subgroups, we begin prototyping and testing.
This phase also includes CAD modeling, but also involved the construction of cheap material prototypes with wood, sheet metal, or cardboard. We can turn our ideas into reality and test them using these prototypes, despite these prototypes being, as we say, “sketchy”. Once we have our mechanism designs planned, we will meet and review the different designs that we will make a final product of. We are unique in that we are one of very few teams that build more than 1 robot, in fact, we build 4. This way, each and every member can work on a robot. We can test each design effectively and asses each robot’s performance in comparison to the rest.
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Traditionally, robots are constructed using a Tetrix robotics kit. These kits have pre-made aluminum parts that have already well aligned holes for bolting. The kit includes all that is needed to build a working robot, but not always an effective one. In our 7 years as an FTC Team, we tend to find issues with making our designs work with the parts we have. To solve this, we often end up manufacturing our own parts out of stock materials. These customized parts fit better in our robot, and can also fit design requirements such as weight, price, and size. This year we decided to do something a little different, where one of our robots was made using numerous industrial design and manufacturing techniques. Very few of the parts on this robot were from the robotics kit, the rest were made from stock material, or made on a machine; such as a 3D printer.
The outcome of our efforts on the robot show at our competitions—where our robot is put to the test against 25-160 other FTC teams—depends on the competition level. In addition, our team has been highly dedicated to spending thousands of hours on outreach programs for FIRST, other FTC teams, and other groups such as Boy Scouts, the Easter Seals, and companies involved in the engineering industry.
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Members of our team not only develop skills regarding engineering, such as: programming, CAD design, construction, manufacturing, budgeting, project management, and more. Our members also develop more communication, teamwork, and leadership skills from working in a group setting. The outcome of our efforts not only comes when we win awards, but when our members become further developed and well prepared for a college and career in STEM.
Nearly 30 percent of your robot was 3D printed. Why did you make that decision? How did 3D printing affect the development of your robot?
Using the Tetrix kit has always had its drawbacks. In addition to not looking as nice, the designs are limited to the parts that are pre-made within the kit. It has been a dream of ours, for a long time, to design and construct a robot using as little of the kit as possible. This included manufacturing our own parts, and CAD designing the entire system.
Our first robot, named Kareem, was the prototype to our final product. This robot was made from the Tetrix kit, and worked very well for a short while. We competed all the way to three finals with Kareem, but after those few competitions, Kareem began to break down and have issues. We understood from there that robotics kits are not meant to last a long time, so if we wanted a consistent, high scoring robot, we would need to make our own parts.
Many of our members have little experience with manufacturing, but, one of our members is a mechanical engineering intern and was able to introduce many techniques to our team. We started working with 3D printers 2 years ago when we combined with a 3D printer company on an outreach activity.
Since then, we have been able to use basic 3D printing technologies for small, basic parts in our robot. We realized that 3D printing was one of the best ways we could manufacture robot parts. It is fast, relatively inexpensive, detailed, precise, and easy to learn!
We love 3D printing, and we love what it enables individuals to do during their design process. Instead of worrying about how to modify a pre-existing part to fit what we need, we were able to make a part that exactly fit our requirements, and print it specifically for our robot! This made our design more robust, reduced the amount of work that was needed to construct the robot, and improved the look and feel of our robot as a whole.
What role did prototyping play in your design process?
We spend a great deal of time testing out our ideas. We love seeing our designs interact with game elements properly. Often, it is a speedy construction of cardboard and duct tape. It is only to test the concept in the action it was built for, using cheap and fast methodology.
Despite our final design being CAD designed, our ideas still needed to be tested. We continued our use of cheap materials like wood and cardboard, but moved on to using 3D printing as a rapid prototyping technology, as well as a final manufacturing technique. We would make parts on consumer based printers to make sure the part fit well in the robot, to make sure its dimensions are correct, and to modify and design flaws that could cause weakness or instability.
What did you find to be the most challenging part of this process and how did you address this challenge?
The most challenging part of our new feat, in designing and constructing a non-kit based robot, was making sure that the reality of our designs was not overlooked.
In CAD, we are able to most clearly see where parts are going to connect, and where they fit among each other. But we cannot easily test the reality of a design without using other techniques. For instance, our lift mechanism was originally thought to be using a chain and sprocket system similar to a system of pulleys. This way, the lift would be driven down rather than rely on gravity to fall to the floor.
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In CAD, all of the sprockets were well in line with each other, and no issues were seen, but in reality, there was so much chain to be used that it was very hard to manage while lifting and lowering. The sprockets were not close enough to the chain to prevent any skipping from occurring. These types of issues could only be seen once the chain was placed on the robot- something we could have seen earlier in a prototype test.
We also had to take the time to use mathematics and simulation in order to assess the reality of our designs. In our younger years as a team, we would construct a gear or sprocket system willy nilly, and estimate if it would have the torque and speed needed for the system.
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We would then test what we built and if it worked, keep it. If it did not, we would rebuild it as needed. Because we cannot test a CAD model, we had to establish power and speed requirements of our designs, and then design a gear train that would enable us with these gear reductions. Using force simulations, and programs like MathCAD, we were able to determine the method of drive we would have on all of our systems before they were put together.
Tune in tomorrow to hear more about lessons the team learned along the way and the surprising way helping other teams has actually created good Karma for FTC Team 3113.
UPDATE: FTC Team 3113 averaged over 500 points per match at the FIRST Championship, ranking 53rd out of 128 teams at the competition, and over 4,000 teams worldwide.
FTC Team 3113: Some Disassembly Required Team Members include:
- Justin Argauer, 10th, River Hill High School: Driver 2, Build team
- Ryan Argauer, 7th, Folly Quarter Middle School: Safety Captain, Photographer, Quartermaster
- Eric Frank, River Hill High School Sophomore, Programmer
- Al Gronlund: Mentor
- Zack Gronlund, 9th, River Hill High School: Spirit Captain, Build team, Driver Coach, Gorilla
- Griffin Holt, 9th, Glenelg High School: Build team, Promote Captain, Judging, scouting captain
- Spencer Mullinix, 10th, Glenelg High School: Build team, technology outreach coordinator
- James Parry, 11th, Chapelgate Academy: Driver 1, Build team, Programming Captain, Co- Captain
- Connor Tinker, 11th, River Hill High School: Design Captain, Outreach coordinator, Judging captain, engineering documentation
- Miles Reidy: Assistant Mentor
- Jeremy Romano, 7th, Folly Quarter Middle School: Quartermaster, judging, scouting, build team
- Henry Soeken, 6th, Folly Quarter Middle School: Quartermaster, Pit design
- Mac Smith, 10th, River Hill High School: Programming, Electrical, Spirit
