Always wanted to build a robot?

Want to do competitive robotics?

 

The Sierra College mechatronics department hosts a Robotics Club for students that are interested in designing and building actual working robots. Besides being a great learning experience, we have a great time! Our current focus is on designing and building a robot to compete in 120-pound combat competitions ("battlebots") but we are also interested in adding sumo-bots, robo-magellin or other competitive robotics to our activities.

 

Want to participate? Join us at a regular meeting. You can stop by our lab in Room V-106 to find out our current meeting day and time or contact our faculty advisor using the "Contact" form on the home page of this website.

Check out the stories of our previous competitions below.

For 4 years we have competed in robot combat competitions at RoboGames in the S.F. Bay area.  RoboGames is the biggest robot competition on the planet. (See picture on right.) Teams come from all over the U.S. and from multiple other countries (Brazil, China, Egypt) just to compete. You can find more information at www.robogames.net

Year 1 (2007): The first year we entered the 1-pound combat competition. No, that is not a typo, there is a 1-pound class. They actually go down to the 150 gram class! It then goes up to the 1, 3, 5, 12, 30, 60, 120, 220 and 320 pound classes. Our first one-pound design was a basic wedge named "Wolverine" and we did alright. Two wins and two loses. Robogames is a double-elimination format meaning once you have lost twice, you are out. We found out that wedges are alright, but especially in the one-pound class, not very exciting.

Year 2 (2008): We went in with a one-pound robot with a spinning-drum weapon. We called it called "Wolverine II". It was a challenge to design a weapon and its drive motor into a one-pound robot, but we did it. Unfortunately, lack of analysis and testing beforehand proved to be a problem. The LiPo batteries we used will destroy themselves if too much current is drawn out of them at any one time. Unfortunately the drive motors that we chose drew more than the rated max current of the battery pack. The weapon looked great for the 15 seconds it spun, but the battery pack soon died, and therefore so did the weapon. We lost two fights in a row due to that and so were eliminated. A good lesson was learned. Finish the robot early and test it ahead of time!

Year 3 (2009): In year 3 we decided to move up to compete with the "big boys". We raised money and designed and built a 120-pound weaponized robot (called, logically enough, "Wolverine III"). With lots of mentoring by a former heavyweight battlebots champion (who also happened to be a student) named Ray Billings, and huge amounts of work by our club members, we did it. (See picture on left.) We had a solidly-built frame and a 17-pound steel weapon spinning at about 2500 RPM. If you have ever swung a 12-pounds sledgehammer you have an slight idea of the forces involved. It was amazing. (See video of the first weapon spin-up here: http://www.youtube.com/watch?v=tk_UaAKoRSU ) We were all amazed and proud. People were going to fear us!

Unfortunately, on the very first round we drew our mentor Ray as our opponent. He spins a 40-pound "lawnmover-blade" that is about 4 feet long, an inch thick and 4 inches wide made of tool steel. Everyone dreads drawing Ray as an opponent because even if you win (which is rare), you are often too damaged to continue competing. We went at it and almost immediately Ray bent our weapon, snapped the axle off the weapon, shattered the bearing block and crushed our left front corner. Still, we kept coming back for more. He would hit us again. After about a minute we could no longer drive due all three of our front skids being broken off. We ground to a halt and tapped out. (See video here: http://www.youtube.com/watch?v=FAMMDrsFaz4 ) We lost. And our weapon system was beyond repair. (See picture on right.) We used a cutter and welder to make our robot into a wedge overnight and actually won one match the next day before being eliminated by a team from Brazil.  (See video of our loss to "Tauro" here: http://www.youtube.com/watch?v=D59Kk9My73M ) Well, our goal was to learn a lot and we did. Our weapon system was too weak. But our frame was awesome. It protected our tires, motors, batteries and electronics like a champ, despite taking the biggest hits any robot in our weight-class can give out. Lots of other learnings, too. We resigned ourselves to going back home and starting to plan for year four.

Year 4 (2010): With a completely redesigned weapon and weapon support system, we fixed our biggest problem from year 3. We also changed to a much higher-performance drive system. We are now spinning almost 30 pounds of high-speed steel with razor-sharp cutting blades at 2500 RPM and we are really fast and maneuverable. (See picture on left.)  (See drive-test video here: (coming soon)). Our first match was with a robot from Lafayette University in Pennsylvania. The match started and they zoomed past us and hit the wall which damaged their weapon and probably their drive system. We only got one "bite" out of them before they tapped out. We won! Not a glorious win since they mostly killed themselves, but a win nonetheless.

Our second match was with a robot spinning a tool-steel blade vertically at an outrageous speed. (See picture below, right) In his previous match against a team from Cal Tech he had destroyed their weapon system, sliced huge gaps in their frame and thrown their electronics all around the arena. (See video of the fight here: http://www.youtube.com/watch?v=a1X0Vgdg8U0 ) This guy was scary. But he admitted that he was also scared of us. His quote: "One or both of us will have to do some major repairs at the end of this fight." The fight started and we tried to maneuver around and get to his tires or frame, but he was smart and kept his weapon pointed at us at all times. So, we went weapon-to-weapon. His first hit broke one of our two blades (tool steel is tougher than high-speed steel). But we came back again with one weapon still spinning. His second hit was on our frame and bent the arms holding our weapon. We were now defenseless and against the wall. Being a good sportsman, he gave us a few seconds in case we wanted to tap out, but we declined. He hit us again and bounced us off the arena wall! We ended up stuck on our side so we finally tapped out. What a great fight! (See video here: http://www.youtube.com/watch?v=isxhUYMEs3s ). We found out later that we damaged (but did not break) his weapon.

We now had four hours before our next match to cut out the damage and weld in new frame pieces. (See picture of the damaged robot below, left.) The team was amazing and four hours later, with less than two minutes to spare, we made it to the arena with a weapon system as good as new! We were back and our opponent was a simple wedge. Looking good so far. Unfortunately, it seems like our battery packs took some impact damage during the previous fight because when the fight started, our battery packs died about 20 seconds into the match. We lost. Lack of battery power is not the most glorious way to lose but everyone loses somehow, this method just happened to be ours today. Since this was our second loss, we were out of the competition. But we won one match, made some new friends and learned a lot. All good things.

So, we have one major task for next year. Improve our batteries and/or our battery shock mountings to avoid damage during big hits and provide enough power for the full match (which by the way is roughly 150 Amperes continuous and up to 4 times that much at startup). We also want to tweak some other parts of our design (e.g. one speed controller broke loose and was flopping around inside the robot). We look forward to making our robot even better.

 

The robotics club has two mottos. The first is from Samuel Beckett. "Ever tried. Ever failed. No matter. Try again. Fail again. Fail better." And the second is, as the Chicago Cubs' fans say, "Wait Till Next Year"! We will be back and we will be even scarier.

 

(Also special thanks to the Sierra College welding department, especially Scott Berry and Bill Wenzel for their support and assistance!)