Week 32 of Vex Toss up, the meetings were as filled as a a turkey on thanksgiving.
In this meeting, we worked on the fundamentals of the robot: The intake, drivetrain, and lift.
For the intake, we worked on 2 abilities
-Storing both large balls and bucky balls at the same time
-Grabbing against the wall
the biggest challenge with this is keeping our large ball grabbing as fast as possible while still obtaining the other characteristics
We first added a divider between our large ball storage and our bucky ball storage. In the past, the balls shared the same storage, preventing us from grabbing both at the same time. We made the divider 5 inches tall and used railings to form the roof. We took advantage of the shape of the 8 inch railings to cup the large balls in the storage. When placing a large ball inside, we could throw bucky balls at the system and the large ball would stay. We then noticed our tower rollers were too short. The large balls couldn't feed into this higher storage. So what we did was raise the tower roller from 4 inches tall, to about 7 inches tall. Because of this, the tower extends well above the storage. To further improve the grabbing ability, we added a slight ramp to the mouth of the intake. We took advantage of the 45 degree gussets to get that angled shape and added standoffs to support the large ball. These standoffs however have a gap which allows bucky balls to enter. To provent these standoffs from squeezing together and trap bucky balls, we added cross bracing on top of the storage.We then added linear slides to the storage to increase our large ball capacity to 2, maybe 3 large balls
We then swapped out our bucky ball rollers to a thicker set. This increases the grabbing range of our bucky balls, but we also swapped our tower roller to a thinner set, decreasing the grabbing range. However due to the increased height of the tower roller, the large ball roller still hits the field perimeter before our bucky ball storage
For the lift, we worked on 2 traits
-Knowing lift height
-maintaining lift angle
the first change was relatively minor. We replaced a couple of chain links with tank tread, and used it as a marker to indicate that the lift is at the height of the column. Using this, the driver can know when the lift is at the appropriate height to score
The second change was more major. With a chain bar, there's a lot of backlash. Because of this, it's difficult to keep the exact angle of the lift. We then added 4 sets of sprockets to the bottom chain. These create tension in the chain, maintaining the angle of the lift. We added these sprockets as close as possible to the hard mounted sprocket, and the mounting sprocket. this way, the chain loops over a few additional teeth. As a result, the intake keeps it's angle a lot better than before, however we didn't get a clean result because we didn't have long enough axles. We tried using couplers, however we couldn't secure the parts with collars.
For the drivetrain, we tried solving its drifting problem
We took the time to inspect the drivetrain. We noticed that our front left chain was very loose, and our right drivetrain didn't have pillowblocks! Because of this, we removed the motors and inserted pillowblocks. As for the front left wheel, we noticed that the motor was inserted a a hole forward. Because of this, we moved the motor back one hole, and we formed a very solid seal. We may actually decide to change this in the future however. Before, the chain was slack, but the chain never fell off. If we make the changes to every wheel, we may actually speed up our drive with less friction.
We created an additional autonomous that starts in the middle zone. The goal of the autonomous is to win the autonomous bonus and speed up driver control by put 3 bucky balls in the column goal, and knock over both large balls, while keeping a bucky ball in the middle zone. That equals to 26 points, which is quite difficult to outscore. The biggest problem with the code however is time. We our current speed of the drivetrain (1.25 to 1 speed) and funnels (6:1 torque), we can't accomplish all tasks in a timely manner. Because of this, we may need to scrap a few parts of the code, or improve the robot accordingly
The autonomous goes like this. The robot starts in the middle zone with its back facing the opposing alliance. The robot then backs up as fast as possible and opens the funnels to guide the 3 bump buckies into the intake. The robot then returns to the alliance tile, where any extra buckies are collected. Then, The robot is oriented and pushes the large balls off the barrier. Finally, the robot is oriented towards the column goal to score.
We also added a few variants to the code to resist defensive play.