We’re excited to be back for another year with openalliance! Based out of the Churchville-Chili Central School District in New York, G.R.R. (Greater Rochester Robotics) has been competing in the FIRST Robotics Competition since 2000.
In this thread, we will be posting weekly updates about our build process, programming, strategy, and more, which you should expect to see every Sunday. Feel free to leave any questions or feedback here as well!
This year, we will be competing in Week 3 at the Finger Lakes Regional, and in Week 5 at the Miami Valley Regional.
After kickoff, we quickly determined that we would attempt to perform the deep cage climb this season. Throughout the week, we were able to test 2 prototypes with positive results.
“Dreidel” Climb
This prototype was incredibly simple; 2 wooden blocks screwed together, attached to a pivot and lever, conceptualized as a dreidel. We could repeatedly pull a robot frame off of the ground with this prototype, however we are apprehensive about implementing this on our robot as it may be difficult to line up in a real match, without modification to the overall design.
Double Bar Climb
Learning from the success we had with twisting the cage, our next prototype resembled the RustHOUNDS Ri3D design with 2 metal bars.
Next Steps
After prototyping, we are feeling confident in our ability to perform the deep cage climb. We plan to revisit these designs once our robot architecture is more fleshed out, so that we have a better idea where these mechanisms may fit on our robot.
Primarily utilizing star wheels, this prototype is intended to intake coral from the floor in any orientation. We found that slight tweaks in the positions of rollers and star wheels can yield large performance improvements, so we may continue to refine this design before we decide if we should include it on the robot.
Coral Station Intake
Currently, we assume that in a match the majority of coral loading will come directly from the human player. Our goal is to be able to receive coral even if we have one stuck between the robot’s bumpers and the coral station, as we imagine that at a competition loose ground coral would otherwise get in the way of coral loading.
So far, we have tested a “passive” intake, that uses gravity and a funnel to feed coral into a future scoring mechanism. We have plans to iterate this design to include agitators to help accelerate coral down the funnel.
We unfortunately don’t have any CAD of this prototype yet, if you would like I could get you some exact measurements at our next meeting on Monday. In essence though, there is a single outer axle of star wheels, with 2 smaller axles on the ground (one with 2" flex wheels, the other is a 2" tube wrapped with silicone tubing). We spent a lot of time tuning where these were positioned, as we found we needed a more gradual incline for the intake to accept the coral over the bumper. I believe overall the intake stuck ~13" outside of the frame perimeter.
After the coral is in the robot, we are just centering with 2 sets of star wheels running in opposite directions, with a center-to-center a bit over 5". These worked tremendously well for consistently pulling the coral through in a single orientation, however we did have some issues where the coral would be stuck sideways for a few seconds before it found its way through.
Just the 2 angled panels, we did screw some polycarb to the inside face to help the coral slide better, which the final design would likely be constructed with.
