With the FTC competition, there are limitations on weight and size of the various components of the robot and, at the same time, the need for strong materials that will bear the weight of the robot (at the beginning and the end of the game in latching on to the lander). To be able to design and build light-weight components that are strong, one device stands out for its capabilities - the 3D printer. Whether it helps us print out last minute objects that are vital to our robot, or prints out life saving human organisms, it is an understatement to say that a 3D printer can do everything. While there might be different models of 3D printers for different uses, they all have the same functions - they intake the material which gets printed out, they heat the material, and layer on the material on a base. For the sake of blog I will focus on household/school 3D printers which could be used to print simple parts such as a phone case.
Center of Gravity is a vital aspect to consider when designing the robot. Without knowing where it is or what it is, your robot may be toppled over for the duration of the match or in our case, in the game of Rover Ruckus, you may not be able to hang on the lander. It is important to always consider where the center of gravity is so that these problems don’t repeatedly occur. Center of gravity or center of mass(when looked at in 3D) is the average location for the weight of the mass. When looking at the center of mass and gravity an important aspect to consider is stability and how to make the robot stable.
Encoders can be a powerful tool for navigating the robot on the field during the autonomous period of the match. An encoder is anything that converts information from one format to another. Many motors such as the REV Core Hex, TETRiX TorqueNADO, and AndyMark NeveRest DC motors come with an encoder. Specifically, these encoders are known as rotary encoders. Rotary encoders are electromechanical devices that track the rotation of a motor shaft. There are many different types of encoders including Optical and Magnetic Encoders. Magnetic Encoders have a magnet which is attached to the shaft of the motor and use two Hall Effect sensors (for more information of Hall effects sensors see: https://www.explainthatstuff.com/hall-effect-sensors.html) to detect the change in the magnetic field as the motor shaft is rotating. These types of encoders are used most of the time in the DC Motors we use for FTC.
In FTC, using linear lifts are very important as they are much more reliable compared to the traditional rotation of a motor. A linear lift is a linear motion system that converts the rotational motion of a motor into a linear motion. There are several types of linear motions systems including rack and pinions, lead screws, linear actuators, and more. However, in this blog, I want to focus on linear slides and the common difficulty: stringing. A linear slide is basically beams that slide on top of each other when pulled by a string. Linear slides are a very versatile form of lifts as compared to the rack and pinions, as an infinite number of stages can be added to create the desired extension length. In relation to stringing of the lifts, there are two types, continuous stringing and cascading stringing. Continuous stringing is easier to do, and requires less force to pull. However, it is slower as it moves each stage of the lift individually. Cascading stringing, on the other hand, is a more difficult but is a faster system that requires a lot more force to pull, but is very useful for quickly extending or retracting a large lift. Continuous stringing, the more basic style, is strung with the string being wrapped around pulleys at each stage of extrusion so that each stage of the lift moves up.