SMC Alumni bot

After many minutes of work analyzing the mechanics of this year’s game, a select few alumni teamed together over Christmas break to create this unstoppable robot. Comprised of all steel, ten 269 motors, a rubber band powered drive, too many gears, a sweet decal and a definitely legal, totally safe propeller. Built by former members of the 1200 teams from St. Mary Central.

Video showing its capabilities

You have beaten us to this!

We were seriously considering building one for the world…

But does it actually have an affect on the balls? (just wondering)I think you could get that ratio higher if you wanted to…

Can you post a video of a robot shooting and that blocking? Also, if you are considering this for a competition (I am guessing you are not :slight_smile: ), don’t you think that if the rubber band drive will get knocked off of its path to goal by some ball or robot.

I worked on this so i will answer the questions.

If you used 393 motors you could easily increase the ratio and make it spin at around 10000 rpm. My target speed to knock a ball far off course would be 13000, which was what leafblowers online that i looked at while doing research for the robot ran at.

We can’t post anymore videos because the robot was taken apart by the high schoolers last week. If you build a funnel for the air like a leafblower the design would work better than this one.

Lastly the drive being elastic is fine because the robot only has to travel 4 feet to be in position. Elastic drives are super fast too, so no robot would block it. We did have 2 more motors we could put on the drive if we ever decided we wanted to drive around.

Although it created a large amount of wind, it was not concentrated so it had little effect on launched balls. However, it could definitely win based on intimidation alone.

I’d just like to point out that this entire project was incredibly scary to watch.

We had to take apart the bot because we were running out of shaft collars and small screws.

We were at competition a month or so ago, where there was a team with a fan bot. We were kind of worried due to our bullet bot design, so we got a fan from one of the classrooms, laid it down on the field and cranked it up to full power. We found that the full size fan had absolutely no effect on the balls trajectory (at least for our robot) due to the speed of the balls. It may have had a small effect on elevation but not enough to stop us from scoring.

Can you place the fan next to a bot shooting the driver control loads? It would be interesting to see if that will have a larger effect on the ball’s trajectory.

I feel like it would be less effective because the ball has more velocity closer to where it was shot

@ThunderRobotics that is true, but I was thinking more of how the fan would be closer to the ball from the driver control load tile.

Has anyone tried making a rubber band powered fan, rather than directly powering the fan? I feel like that might be more effective (it would spin faster). After California’s State in Pasadena, I will give it a shot. I’m thinking of using a 1:25 gear ratio, with a pneumatic transmission to disengage the 6 motors on the fan (leaves 4 for a holonomic drive). It will also need a funnel to concentrate the airflow and reduce turbulence. I’m not sure how effective it will be, but we will see.

You could use the plastic sheet to make a shroud and funnel, also maybe use a ripcord to start up the propeller