Hello again, CD!
As a fun little CAD exercise, @ninjadrknss and I decided we wanted to make a full robot CAD in 3 days as a proof-of-concept design for our team. We settled on the following robot design:
This robot includes a 3-stage elevator that reaches up to 7ft to score in the L4 reef level and a wristed end effector that kicks out algae and collects and scores coral. Since the elevator is relatively simple (as we chose not to rig it in CAD), I will only go over the end effector in more detail.
The end effector was inspired by 1678’s 2023 intake, various 2019 intakes, and the Cranberry Alarm Ri3D algae kicker. It has a 48:1 deadaxle pivot, a 1.3:1 step-up for the kicker, and a 1:1 ratio for the intake rollers. The wrist should be stored at ~80 degrees, deployed for pickup at 120 degrees, deployed for scoring L1-3 at 210 degrees, and deployed for L4 at ~250 degrees.
This is the gear train for the pivot. The 80t gear is bolted to the polycarbonate intake plate, allowing the pivot shaft to spin freely. The pivot shaft then transmits the power to the intake wheels. This keeps as many motors off the pivoting wrist as possible.
This is the path taken by the belts to power the intake rollers. Power is transmitted via the pivoting shaft to the bottom roller before the direction is reversed to the top roller. Both motors are stored in the 3x3 box tube for packaging, but should still be rather easy to remove due to the cutouts in the back of the tube.
Strategy-wise, we decided that for our team, it would make sense to go with a single mechanism on an elevator, and we chose to focus on scoring coral at all levels. We then determined that picking coral up from the ground would be quite difficult, so we settled on chute pickup only. Later, we added the algae kicker to be able to score in more locations on the reef. While we were toying around with a design to intake and score algae in the processor, we decided it would be easier to either try and herd the algae into the processor (seen in an Ri3D team’s Instagram reel) or leave it to an alliance partner.
As for climbing, @ninjadrknss claims he’ll CAD it tomorrow. Whether that statement holds is yet to be seen. I’ll reply to this post if we update the robot with a climber mechanism.
If you want to look at the CAD in more detail, all the files are posted publicly on my github. As always, any feedback is appreciated!