For all of you who are not FRC veterans, there is a group online called “robot in 3 days” who after the FRIST game is revealed proceeds to build a robot to do that game in, you guessed it, 3 days. Maybe it is to inspire all the teams out there who can barely get a robot together in 6 weeks let alone 3 days. To me it seemed almost mocking us as they show off what they can do and usually have a robot that can score better than any of our robots. So I rarely look at the posts. Anyway, team 702 usually likes to find a way different approach to the game and seeing stuff like that can stifle creativity. (As well as making me want to stifle them right up their…)
So what is their secret? They don’t have to follow the rules. They are not competing in any event, so they are not bound by the rulebook. Its still seemingly impossible to build a fully functional robot in 3 days even when throwing out the rules. Yeah, totally impossible. No normal team can do that…
So it really is quite liberating when you can build a robot without any real rules or regulations. The team was recently given the task to build a fully functional omnidirectional driving robot as a prop for… well I cannot say quite yet. It didn’t have to compete and the only rules were it had to be able to drive in all directions and couldn’t break down. Also there was no time to order anything so we could only use the spare parts we had in the room. We had an old frame still built so that became the chassis (very illegal in FIRST to use a prebuilt structure) and had some left over custom brackets from this year’s robot. We managed to find enough parts to reconstruct 4 transmissions and reused some old Mechanum wheels from 2012.
Never heard of Mechanum wheels? They’re designed to drive at 45 degree angles so that by cancelling the x or y vector of thrust you can… Ok, I’m a nerd, what do you expect from a High School robotics coach. Here’s a picture and let’s just say that they can drive in any direction depending on how you spin them. (top ones are the mechanum wheels, and yes they’re covered in little rollers at angles that spin freely)
We got it all together, used an old battery mount, got an electronics board on it using a lot of velcro (again, really kind of against the rules) and programmed it to drive like a first person shooter video game using an X-Box controller. Then we debugged some wheel issues and tested it thoroughly to make sure it would perform on cue. It drove beautifully and did everything it was supposed to.
And how long did it take us from the day we got the assignment to completed robot?
… You guessed it, 3 days.
-Davis (Head Coach)