To begin, you will be creating a layout sketch of the drivetrain. This will dictate the size and position of the drive tubes. The layout will be drawn from the side and top view of the drivetrain. For your swerve drivebase, you will make it 26"x26".
Instructions
Start by creating a new Onshape Document called Stage 1D Robot and within it, a new part studio called Main Layout Sketch. Then, use the Origin Cube Featurescript to create an origin cube. Follow the instructions in the slides to complete the layout sketch.
As previously explained, this method of top-down modeling is extremely powerful as it enables you to capture the most important dimensions all in one place. However, you should be careful to not over-detail layout sketches. You will be practicing layout sketches all throughout Stage 2, and use them in Stage 3 alongside multi-document practices to design a whole robot.