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https://github.com/team236/2017-robot

⚙️ Team 236's 2017 robot to play FIRST Steamworks
https://github.com/team236/2017-robot

236 eclipse first first-frc first-robotics-competition frc frc-robot frc236 frcjava java robotics robotics-competition robots team236 wpilib

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⚙️ Team 236's 2017 robot to play FIRST Steamworks

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README 

        
# 2017-Robot

Team 236's robot for 2017 FIRST Steamworks



## Subsystems

The robot has 5 distinct subsystems:

* Drive

* Climber

* Garage door

* Intake

* Shooter



### Drive

The drive system this year is a 6-wheel drop-center tank  drive on Colson 4-inch

wheels, which provides maneuverability and traction. Each side is powered by

twin CIM motors connected into a WCP DS gearbox with a two-speed pneumatic

gearshift which provides two distinct speeds to give greater control over the

robot.



Because the robot is a tank drive, 236 is using our

[TickTank](http://github.com/Team236/TickTank)

class which provides a variety of features including motion profiling and

abstract interfaces. More information on motion profiling, turning and other

autonomous behaviors is in the Autonomous section below. By default, the tank

drive runs in a simple tank drive control mode on two joysticks. However, the

driver is also provided with buttons to activate a more precise drive mode for

alignment with the peg for gear delivery and a reversed drive mode. Because this

year's robot has functions on both sides of the robot, it lacks a clearly

defined "front." Giving the driver the ability to reverse the drive can make

driving more intuitive.



### Climber

The climber is the simplest subsystem of the robot. It consists of two 775Pro

motors mechanically linked with a VersaPlanetary dual-input gearbox attached to

a custom-built wheel designed to capture a knot on the rope. A racheting wrench

is used to prevent the weight of the robot from causing the motor to backdrive

and to hold up the robot when the match ends and the motors lose power.



### Garage Door

The garage door is the colloquial name given to the robot's gear delivery

device. It is so named because the movement of the mechanism approximates that

of a garage door. The door part consists of a lexan sheet attached to delrin

tracks that allow it to roll up and down and spin by 90 degrees. The raised

position allows the gear to easily slide onto the door. Then, the lowered

position allows the gear to be placed precisely onto the peg for delivery to

the airship. The door also has a cutout designed to push up the spring so the

gear can be placed without actuation.



On the front of the garage door are two small arms made of delrin that can be

opened and closed. When the robot receives a gear from the loading station, it

opens the flaps to guide the gear to the correct position. When the door is

lowered, the flaps close to hold the gear securely while placing it on the peg.



The garage door is powered by two pneumatic pistons - one to pull the door up

and another to open and close the flaps. This allows powerful control over the

door while simplifying the wiring and programming.



### Intake

The intake of the robot is an arm that is lowered over the bumpers to obtain

fuel and move it to the hopper. The intake roller is powered by two 775Pro

motors with gearboxes on opposite sides of the intake. The intake arm is

lowered over the bumper by a pair of Bosch seat motors on opposite sides of the

robot. Limit switches on the top and bottom of the intake prevent the seat

motors from driving into the floor or the robot. Because seat motors burn out

very easily, these limit switches are crucial in preventing damage to the

motors over the course of the season.



### Shooter

The shooter is one of the most tightly tuned and controlled components of the

robot. Fuel is launched by a flywheel which rotates at speeds of around 3,000 to

4,000 RPM to push fuel around a curved hood. The hood itself is a curved piece

of lexan held in place by a custom-machined aluminum frame, which is raised and

lowered by a linear servo.



Because the flywheel is compliant and can expand, there is a lot of pressure

between the ball and flywheel at high speeds. The increased friction increases

the load on the flywheel significantly, lowering its speed when the next ball

enters the hood. To prevent this, we run a PI loop at 200 hz which uses a banner

light sensor to count the speed of the wheel and to vary the motor speed to

maintain a consistent RPM. Using this system, we are able to return to full

speed after shooting a ball within hundredths of a second.



The shooter can be set to a variety of different "presets" which have an

associated speed (in RPM) and a hood angle (absolute). This provides a variety

of different points on the carpet to shoot from, making the robot harder to

defend. In order to align the robot with the boiler, the robot has a flashlight

which the drivers can see on the boiler stack, as well as a camera which can be

rotated to see the boiler. Later in the season, we may add a coprocessor to run

vision on the robot to aid in alignment.