Robotics Education & Competition Foundation
Online Challenges

4/6/8 bar lock nut bracket


Entry ID #: 6667
Created: Tue, Jan 15, 2019 12:53 PM

Cad Challenge Report This part was made to hold an untightened lock nut perfectly in place while keeping its original functionality. In my VRC robot a 4 bar lift is used to pick up the cap pieces and score them as a high cap. Our 4 bar design uses screws and lock nuts to hold the c-channels together, but the lock nuts is slightly loosened from being fully tightened to allow the arm to move. The problem is whenever the arm moves, there's a small amount of friction between the screw, locknut and the c-channel that starts to untighten the lock nut more than needed and makes the arm more difficult to use. What the cad part will do is hold the lock nut away from the c-channel and also keep it in place to remove that friction. In Fusion 360 (V.2.0.5278), I created a makeshift c-channel and made a sketch on top of that using the holes from the c-channel itself to make sure I got the dimensions right. I then sketched the part’s entire shape in that sketch using parameters to be able to change everything that needed to if I needed. I extruded the profiles to make the part and also added a thin layer at the bottom of the hole to make a solid surface to be able to be 3D printed without support material. Some chamfers were added to make the part’s edges less sharp and look cleaner. Using 3D cad is something I already do often so I will definitely use it in the future more more projects like organization, modifications, repairs, replacement, and stand alone projects. Cad softwares like Fusion 360 are helpful in which concepts for mechanisms in the robot can be sketched up and modified to fully design and understand how it works and how to build it. Learning 3D cad will definitely help on me on my career path because it is a very useful skill that employers would want.