Hello! Welcome back to IntroVex, your robotics guide to VEXcellence.
We compared the differences between VEX IQ and V5 competition designs and overviews in previous episodes. Starting from now, we will start including some "robotics" ideas for the competition, such as constructing a robot and programming. If you are someone who struggled during robot preparation, maybe this is the kind of article you're looking for!
This time we'll be discussing what makes up a robot and talk about common aspects of a robot. You may often see a robot as one big system/structure, but they are often constructed of different subsystems. Knowing the types of subsystems often incorporated in robots can benefit you during both the brainstorming and construction stages, meaning you don't have to think and build the whole robot in one go. Rather, you can think about each subsystem one by one, and then finally combine them into a robot.
The common subsystems include the following: Chassis(Drivetrain), Intake, Scorer, End Game Mechanism, and other subsystems based on the year's game.
Chassis / Drivetrain
The chassis, also known as the drivetrain, is the base of a robot. This subsystem is usually the one you start with because the structure of your base will decide how to cooperate with other subsystems.
One of the most important aspects of deciding on the drivetrain is the gear ratio. Gear ratio is the ratio between the gear driven by your motors to the gears driving your wheels. If you have a higher gear ratio, meaning you use a larger gear on your motor than the wheels, your robot will have a faster speed. Oppositely, if you have a smaller gear ratio, your chassis will run slower but have more torque.
Simply put, use a higher gear ratio when the game requires fast movement speed, but use a lower gear ratio when your robot is heavy and big, as a fast drivetrain with a heavy top will make the overall speed even slower.
Another important aspect to consider is the number of motors and wheels you use. Motor usage may have to be considered alongside other subsystems. If there are many missions to complete on the field, you might have little motor usage available left.
For VEX IQ, the number of motors used on the chassis usually goes around 2-4, since the motor limit is 6. For VEX V5, the number of motors used is usually 4-8. The VEX V5 game gives you more space for creativity, so there might be a robot using all 8 motors on the chassis, and using PTO or pneumatics for other functions.
Intake
The intake is the subsystem used for picking up the game object, for example, balls or blocks. Usually, intakes are constructed with wheels or rubberband rollers, but some intake designs can also be plowers or claws that also show the ability to hold onto the game object.
If the game object is a round object like a ball or the triball in over under season, using a wheel or rubberband roller is common and simpler. Some special intakes include the hero bot for this year's VEX V5 game, High Stakes. It uses a passive ring grabber to hold onto the ring and pushes it out with a motorized mechanism. A More detailed explanation can be found in VEX's official YouTube introduction above.
Scorer
Next, a scorer is often the subsystem used to score the game object. For example, for shooting a ball into the goal, or putting rings onto a game element. The scorer doesn't have to be a shooting structure, it can be a conveyor belt like this year's High Stakes V5 game, or the elevator used in VEX IQ Full Volume.
Depending on the game, scorers can have tons of designs, and they usually keep evolving as the season progresses. One of the most common scorers is shooting mechanisms, exemplified in Pitching-In, Slap Shot, Over Under, and this year's VEX IQ game, Rapid Relay.
Common types of shooters include flywheel, puncher, and catapult. Flywheel uses one or two wheels and shoots out the game object straight by sliding it between the wheels that spin super fast. Puncher uses a linear moving stick to hit out objects through a straight line, like how I designed the shooter during Slap Shot. A catapult is a mechanism that first drops to the lowest point, and then shoots out the object by sudden release, creating a parabola when the object is sent flying.
Sometimes, scorers are combined with intakes, like the Rise-Above season where we use claws to stake game objects, so don't limit yourself to these categories. Finding the most creative and useful solution is most important when designing your robot.
End Game Mechanism
Some games include end games like elevation or touching something, and the end game mechanism is for this. Since how the end-game scoring is done varies in every game, it is hard to state what one will look like, but you may get a sense of it by some examples.
During the Pitching In season, we had to elevate from the ground. The low elevation is often done with passive mechanisms by running the robot onto the stick for elevation, same with Over Under's low elevation. High elevation requires some creativity, and it depends on the stick for you to climb. In Pitching In, we had a wall to support our robot and a horizontal stick to grab onto, so we used a 4 bar lift structure to climb. However, elevations in this year's High Stake provide only horizontal sticks and not a wall, so the hanging structure will be more complicated.
Other mechanisms
Some other mechanisms may include supporting hooks or hands to push away game elements and stuff, it can be moved using a motor or pneumatics.
An example is the wing used to push triballs during Over Under, which functioned through pneumatics. Another example is the robot guide used to touch both sides of the walls in Rapid Relay, it doesn't have motors nor pneumatics for movement, but it is an important subsystem to have for particular strategies.
These are more game-specific, and teams often develop their own, so it is not much for generalization.
This is about all for the subsystems of a robot. I will continue to introduce different subsystems in detail in the future. If you like this type of content, please let me know!
This is IntroVex, your robotics guide to VEXcellence, see you next time! Bye~!!
