Are you ready to take your FTC robot's drivetrain to the next level? In this blog, I'll dive into the exciting world of designing a belted drivetrain using CAD and OnShape. This drivetrain will feature mecanum wheels for omnidirectional movement, odometry for precise navigation, and a belted drive for efficient power transmission.
Understanding the Basics
Before I delve into the specifics of the design, let's quickly review the key components of our drivetrain. First of all, what is a belted drive? Basically, a belted drive is a drivetrain system that uses belts and pulleys to keep your motors compact and have very smooth driving. For our belted drive, I am using mecanum wheels, which are special wheels with angled rollers around them, allowing the robot to move in any direction without changing its orientation. This provides excellent maneuverability, perfect for navigating around obstacles and reaching game elements.
Next, odometry is a method used to track the robot's position and orientation on the field. It relies on sensors, called encoders, to measure the movement of each wheel accurately. This information is crucial for autonomous navigation, as it allows the robot to follow precise paths and perform complex maneuvers. For a good belted drive, you need a way to fit odometry pods, with the dead wheels and encoders.
Designing the Drivetrain
Now that we have a clear understanding of the components, let's start designing our drivetrain using CAD and OnShape.
Plate Design: Firstly, I began by designing the frame of your robot. The frame should be sturdy enough to support the drivetrain and other components while being lightweight to maximize speed and maneuverability. I did this by “pocketing” the plates, removing as much unnecessary material as possible. Surprisingly, this also makes the plates stronger in a way.
Wheels: Secondly, I added the mecanum wheels on the frame, ensuring that they are correctly aligned for omnidirectional movement. I created pulleys to attach to these wheels, for the belt to wrap around. Use the wheelbase and track width calculations to determine the optimal placement for stability and maneuverability.
Motor Placement: Then, I added motors where I made holes in my plates to securely attach the motors to the frame.
Belted Drive System: Then, I designed the belted drive system using pulleys and belts. After some math and calculations, I ensured that the belts were securely placed along our pulleys
Odometry Encoders: Finally, I integrated encoders into the drivetrain to track the movement of each wheel accurately. Just to mention, the attached images are using Loony Squad's open-sourced odometry pods, called LoonyOdo. Check them out here: https://www.theloonysquad.com/
Conclusion
Designing a belted drivetrain with mecanum wheels and odometry is a challenging yet rewarding task. By using CAD and OnShape, you can create a high-performance drivetrain that will take your robot to the next level. I hope this blog has provided you with valuable insights and inspiration for your next FTC robot. For a video of how to do this, check this out:
Happy designing!
