Building Robot Paddles to Collect Balls

Robotics is much more than just screwing together nuts and bolts; it requires programming, designing, and lots and lots of planning before even getting to the build stage. That’s exactly what RM Robotics does year after year in the FIRST Tech Challenge competition. Each year, a group of about 10-15 high school students collaborate to construct a robot to accomplish a challenge laid out by FIRST, an international organization that promotes changing youth culture so becoming a scientist or engineer is as desirable as being an actor or athlete. This year, after a build period of roughly 6 months, our robot FeRMi was created. He can collect and lift wiffle balls up to four feet into the air, as well as precisely deposit them into tubes. image 0

FeRMi is made from multiple materials, each of which had to be considered by the team. In order to move quickly around the field, FeRMi has green Mecanum wheels which allow him to strafe side to side. FeRMi also wears polycarbonate guards that protect him from other robots during competition. One interesting piece of FeRMi that required a surprising amount of engineering and science is the harvester in the front that has green silicone paddles to help collect balls for our competition. To illustrate the complexity of engineering every part in our robot, we’d like to share the steps we went through to create just that one aspect of FeRMi. You can make this too, just follow our steps using this product.

1: Carefully pour out equal parts yellow and green silicone liquid, and remove all air bubbles. This can be done by lightly moving the cup in a circle and gently tapping on the corners. Be sure to weigh the containers to verify you are using equal parts of both components.

2: Carefully pour both liquids into a cooled container. We placed a smaller container inside a larger one filled with ice water.

3: After pouring, combine the two liquids into one bright green color, then remove all air bubbles (again) from the mixture. This picture demonstrates the mixing, not what the final product should be; the mixture here still has two distinct colors.

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4: Prepare paddles with holes cut out in them. The holes are required so that the silicon rubber can solidify through and not slide off the paddle. image 2

5: Dip your paddles in the silicone rubber mixture and then use a heat gun on the paddles to remove excess silicone rubber and harden the silicone. Make sure to place newspapers (or another table cover) below your workspace to ensure it’s kept clean.

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6: You’re finished! Now you’re ready to build the rest of the robot! image 4

Come see RM Robotics, an award-winning robotics team from Richard Montgomery High School, demo their robot, FeRMi, at the Silver Spring Maker Faire. For more information, visit the team’s website at