Robotics Education & Competition Foundation
Online Challenges

44691X Rotating License Plate Mount

1

19oselby
Entry ID #: 5812
Created: Wed, Jan 9, 2019 9:26 AM


The Problem: When it comes to mounting license plates, there are many options. A majority of teams seem to utilize a fairly common system: screw the blue and red plates together using ¼” standoffs, and attach two 3” standoffs to a metal plate/channel onto which the plates can slide. While this system is relatively quick, simple, and secure, it relies purely upon the outward force the standoffs apply to the plates, which will eventually result in warping of the metal and the standoffs. An alternative system involves attaching the plates directly to a metal plate using nuts and bolts. This offers even more security; however, changing plate colors between matches consumes much more time than should be needed. A third mounting method requires sticking velcro onto the plates and the robot. This is the quickest method, yet is horribly insecure; the plates may fall off during a match. One last system involves 3D printing a holder. These holder are essentially a 3-walled prism with no top, allowing the plates to be slid into it. While this system offers a solution to the speed with which plates can be changed, it fails to address the security issue. Our Thoughts: What if there was a secure way to quickly and easily switch between plate colors without having to fully remove them from the bot? Our Solution: By attaching both color plates to a rotating mount, the colors can be switched with ease. How it Works: Rotating Mount - The rotating mount is the piece that attaches the plates to the robot. It consists of a 0.19”R x 1” cylinder with a 0.1”R hole (1.1) running through it. There are two mounting holes (1.2-4) on either side of the cylinder. This piece requires a space of 1 hole x 5 holes to mount, and can be mounted in both vertical and horizontal orientation. Plate Bracket - The plate bracket is the piece to which the plates are bolted. It consists of two 0.08”R mounting holes (top left and bottom right) (2.1 & 2.2) for the plate bolts, as well as two 0.2”R holes for attaching to the Rotating Mount. It also includes a 0.1”R x 1.5” hole for the short lock rod, and a 0.2”R x 3.0” hole for the long lock rod. For vertical attachment to the rotating mount, the side hole (2.3) is used. For horizontal attachment, the bottom hole (2.4) is used. When the lock rod is removed, the bracket is able to rotate. Short Lock Rod - The short lock rod is inserted into the 0.1”R x 1.5” hole (2.4) on the Plate Bracket while is is attached to the Rotating Mount in the vertical orientation. It is a 0.195”R x 1.5” cylinder, topped with a 0.2”R x 0.14” cylinder to allow it to be pulled out. It also includes a 1.05”R x 0.05” detend to lock it into the plate bracket. This piece slides through the hole in the Rotating Mount to lock the Plate Bracket into place while it is on hole 2.3. Long Lock Rod - The long lock rod is inserted into the 0.1”R x 3.0” hole (2.5) on the Plate Bracket while is is attached to the Rotating Mount in the horizontal orientation. It is a 0.195”R x 3.0” cylinder, topped with a 0.2”R x 0.14” cylinder to allow it to be pulled out. It also includes a 1.05”R x 0.05” detend to lock it into the plate bracket. This piece slides through the hole in the Rotating Mount to lock the Plate Bracket into place while it is on hole 2.4. Using Inventor 2018: We used Autodesk Inventor (2018) to model our parts for this challenge. When working on the first versions of these parts, we used calipers to take measurements of the license plates (length, width, depth, holes & hole positioning). We printed several tests, and refined/adjusted measurements and dimensions. The final models include rounded edges using the fillet tool, to allow easier insertion and to give a more appealing appearance. What We Learned: Although each of our teammates had a decent understanding of Inventor, this project allowed us a greater understanding of how certain details of one part interact with other parts, such as the detents on the lock rods, locking the rods into the plate bracket. We used Autodesk Inventor Professional 2018, Student, which is downloaded onto all of the computers in our school’s workshop. Making it Real: After determining that this part was legal for use in a tournament, we printed all of the parts and attached them to our robot. During the next tournament, we never once had any reason to be concerned about the plates falling off of the robot (it even took a beating in the final round, when an opposing bot ran directly into it). Between matches, we were able to quickly and easily switch between alliance colors without having to remove the plates at all. Once the tournament was finished, we concluded that this design effectively solved the issues of ease of mounting, speed of switching colors, and security of the plates, all without getting in the way of other mechanisms and satisfying all guidelines.