To accommodate for the different gameplay this year, we decided to modify our middle shooter hood position. Our shooter hood has three positions: the outer and inner positions are actuated using a piston, and the middle position is a catch with two sheet metal hooks and a pair of solenoids.

First, we used the existing design to find the shot angle and height and brought this information (along with the linear velocity of the shot, which was determined to be 104.72 ft/s at 6000 rpm) into a design calculator. The design calculator determined the shot trajectory and that the closest we can be to the power port at the middle hood position is 134 inches (accounting for air resistance).

The programming team then tested the shooter at different distances (x axis) and their corresponding flywheel speeds (y axis), as seen here:

The middle hood position is represented by the red curve, and during testing we noted that point H, which is closer than 134 inches, missed a few times. It was then decided that the middle hood position should overlap with both the range of the trench shot and the wall shot, and that it should make shots between 80 and 190 inches. By adjusting the shot angle to 40 degrees, we were able to achieve this: at 6000 RPM, we can make a shot at 82 inches away, a huge improvement from previous calculations. This hood position also allows us to shoot from a variety of locations using software that dynamically changes the shot speed depending on the distance from the goal. So, by changing the shot velocity to 40 ft/s, we can make shots from the trench zone. This achieves our goal of creating a middle shot profile that overlaps with both other profiles, and, by adjusting the shot velocity, we should be able to shoot into the inner goal as well.

We then used this geometry to move the stop for the middle hood position in our CAD. To do this, we drew a line at a 40 degree angle to simulate the 40 degree shot angle, and used the existing solenoid location to move the catch up a few inches from its existing position.

This required the mechanical team to swap out the two catch plates in the shooter, which arrived a few days ago and were powder coated on Saturday. We did this yesterday, and the programming team is going to characterize the new shooter hood position later this week. We’re planning on posting an update then, and of course let us know if you have any questions!