concept drawing

I am building an Escape Room puzzle prop similar to a marble maze. Below is a description of the project. I need a simple drawing of the prop. The prop is 42" square and visually divided into 4 duplicate triangles. The 3/4" ID tube in the attached pictures is the path a 5/8" diameter marble must navigate from the starting point (near the base of the triangle) to the center of the puzzle. The maze will be installed on a plywood base supported by four springs. The players will work together to tilt the puzzle to move the marble. The tunnel must be open on the top so the marble can be seen, but the opening must be too narrow for the marble to be removed or inserted through the open top. (See drawing) The tunnel is a King Cobra coiled on slate (arranged for support). Players will drop the marble into the mouth, then navigate the marble to the tail. All parts of the prop must be SOLID. All potential weak spots (like Cobra teeth) must have support. The Cobra body will be partially embedded in the rocks for strength (See drawing) and, when passing under itself can be mostly embedded. Using the tunnel exit point as the base plane, the tunnel low and high points must be equidistant from the base plane. The puzzle will have a 6" square opening in the center to accommodate a 6" square block. The marble paths will end on the top surface of the block, where each marble will drop into its own shallow recess, so it will remain stationary as the maze moves. When all four marbles reach the block, the block will rise, reveling the four sides of the block. I need a simple black and white line drawing to help with the CAD rendering. Since I will be printing 4 duplicate Cobra on rocks I only need one.