Robotics Education & Competition Foundation
Online Challenges

Square C-Channel Screw


Entry ID #: 4468
Created: Wed, Jan 3, 2018 12:28 AM

Purpose: The Vex Robotics competitions force teams into difficult problems, requiring them to quickly create and communicate designs, repair parts on the robot, and create the robot itself. When communicating designs, building a prototype is the most effective way of testing the efficiency and reliability. However, building a prototype can take a bit of time, with the hassle of tightening temporary screws, nuts, and structural supports. The square c-channel screw eliminates the need of the hex keys, because the screw holds on to the c-channel. The square base makes overtightened screws easy to take apart, so overtightening screws can provide the short term structural support needed in a prototype. Creating and repairing the robot requires speed, but screws in hard to reach places can hinder the team's ability to build and repair quickly. The square screw fixes this issue because it does not need a hex key to prevent it from turning. As a result, teams only need to reach the nut attached to the screw, which makes building and reparing the robot easier. Moreover, the screws are slightly smaller than the square mounting holes in the VEX metal. This can lead to the metal slipping and shifting slightly, and makes it almost impossible to have screws centered in their holes. Thus, it is incredibly difficult to ensure that any given connection, even with 3 or more points of contact, actually forms a square angle. This is most evident in subsystems such as lifts and drive trains, in which a small amount of friction due to misaligned mounting metal can cause significant error because of the high load placed on such subsystems. Our team has had significant difficulty with this, as proper triangle bracing requires that the two legs of the triangle be perpendicular to each other. We faced such difficulty that our team captain brought in a construction square from home in order to assist in our building. Even with this, adjusting the metal properly was a tedious process. The Square C-Channel Screw fixes this by beginning with a square section designed to perfectly align the holes, thus ensuring that the metal is properly aligned. Design: The square screw was designed in Autodesk Inventor 2017. Autodesk Inventor uses an intuitive system of sketches and features, so creating the part only required a new sketch of the shape of the c-channel hole, an extrusion, and a few filets. Conclusion: Before our team learned how to cad, our lead designer had to plan out the robot out mentally, and even if the design was perfect, the rest of the team cannot see the design. However, Autodesk Inventor allows the lead designer to communicate the design of the robot in a way that the team can comprehend. The ability to clearly communicate ideas unlocks the team's full potential because everyone could build a part of the robot accurately. Our team will continue to use Autodesk Inventor as a tool to maximize efficiency in the future.

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