CAD DESIGN WORKFLOW FOR ROBOTICS

OVERVIEW OF THE DESIGN PROCESS

The Iterative Design Cycle

The CAD design process in robotics is an iterative cycle that transforms ideas into real-world products. It provides the foundation for building efficient and optimized robots for FTC competitions.

Below are the 7 essential steps of the engineering design process that every robotics team should follow.

DETAILED BREAKDOWN OF THE 7 ROBOTICS DESIGN STEPS

Below is a detailed explanation of each step in the CAD design process for FTC robots, including recommended tools, implementation methods, and expected outcomes.

1. DEFINE THE PROBLEM

Detailed Description:

• What problem are you trying to solve?
• What are your specific objectives?
• Example: The robot needs to collect balls and shoot them into a high goal.
• Establish a clear scoring strategy.

Tools and Methods:

• Carefully analyze the game manual.
• Brainstorm ideas with the entire team.
• Analyze potential competitors and their strategies.
• Discuss possible game strategies.

Expected Outcomes:

• Clearly defined objectives.
• Well-defined project scope.
• Initial game strategy.

2. IDENTIFY REQUIREMENTS

Detailed Description:

• List all specific requirements.
• Consider budget, flexibility, and durability.
• Identify technical constraints, such as robot dimensions and weight.
• Define performance requirements, including speed, accuracy, and operation time.

Tools and Methods:

• Create a detailed requirements checklist.
• Analyze available resources.
• Evaluate technical feasibility.
• Review robot designs from previous seasons.

Expected Outcomes:

• Detailed list of requirements.
• Approved budget.
• Specific project timeline.
• Clearly defined technical constraints.

3. BRAINSTORM & CAD DESIGN

Detailed Description:

• Sketch possible solutions.
• Start with paper sketches or 2D drawings.
• Develop ideas into detailed 3D CAD models.
• Design individual mechanisms, such as the intake, shooter, and drivetrain.

Tools and Methods:

• Sketch ideas on paper or whiteboards.
• Use Onshape or Fusion 360 for 3D modeling.
• Use Tinkercad for simple conceptual designs.

Expected Outcomes:

• Initial 2D sketches.
• Complete 3D models.
• Fully developed CAD assemblies.
• BOM (Bill of Materials).

4. CREATE A PROTOTYPE

Detailed Description:

• Build the first physical prototype.
• Verify the feasibility of the proposed solution.
• Use simple and affordable materials for prototyping.
• Test basic functions and mechanisms.

Tools and Methods:

• 3D print complex components.
• Assemble prototypes using available robotics kit parts.
• Use temporary materials such as cardboard, wood, and acrylic.
• Simulate real competition conditions.

Expected Outcomes:

• Physical prototype.
• Functional test components.
• Video recordings of the testing process.
• Initial performance evaluation.

5. TEST THE PROTOTYPE

Detailed Description:

• Conduct comprehensive prototype testing.
• Test the prototype under different operating conditions.
• Identify errors, weaknesses, and potential failures.
• Evaluate durability, stability, and reliability.

Tools and Methods:

• Test on an accurate mockup of the competition field.
• Record videos for detailed analysis.
• Collect measurable performance data.
• Conduct durability and stress tests.

Expected Outcomes:

• Real-world testing data.
• List of problems that need to be fixed.
• Detailed performance evaluation.
• Video analysis of test results.

6. ANALYZE & IMPROVE

Detailed Description:

• Collect and analyze testing results.
• Identify the root causes of problems.
• Make improvements based on real-world feedback.
• Experiment with alternative solutions.

Tools and Methods:

• Organize team meetings for in-depth analysis.
• Modify CAD designs based on testing results.
• Experiment with different solutions.
• Seek feedback and advice from mentors.

Expected Outcomes:

• Improved CAD designs.
• Detailed modification and repair plans.
• Clearly prioritized improvements.
• Updated project timeline.

7. FINALIZE THE DESIGN

Detailed Description:

• Refine every detail of the robot.
• Ensure smooth and reliable operation.
• Optimize weight, performance, and overall efficiency.
• Prepare the robot for actual competition.

Tools and Methods:

• Complete the final assembly professionally.
• Optimize the robot's overall weight.
• Conduct final tests before the competition.
• Prepare comprehensive technical documentation.

Expected Outcomes:

• Fully assembled and functional robot.
• Complete documentation.
• Competition-ready robot.
• Spare parts for maintenance and repairs.

REAL-WORLD EXAMPLE: FTC DECODE 2025–2026

INTAKE DESIGN FOR THE DECODE SEASON

The challenge requires the robot to collect balls and shoot them into a high goal. Depending on the characteristics of this season's game elements, teams can choose from several intake mechanisms.

1. REQUIREMENT ANALYSIS

• Rubber Band Intake: Provides good grip and is relatively easy to manufacture.
• Rubber Tubing Intake: Effective for collecting balls while reducing the risk of jamming.
• Compliant Wheel Intake: Offers a balance between performance and durability.

2. IMPORTANT TECHNICAL REQUIREMENTS

The intake rollers should provide sufficient surface speed to collect game elements effectively as the robot moves.

In many designs, the intake surface speed needs to be higher than the robot's forward speed to ensure reliable collection. However, intake RPM does not necessarily have to exceed drivetrain RPM because their wheel diameters and gear ratios may differ.

3. INITIAL CAD DESIGN

• Select appropriate gear ratios to achieve the desired intake speed.
• Design 3D-printed intake rollers with optimized rubber-band patterns.
• Calculate suitable contact angles between the rollers and the balls.
• Determine precise spacing between intake rollers.

ADVICE FROM FTC EXPERIENCE:

1. Start Early:

The process from initial prototyping to the final product can take a considerable amount of time. Therefore, teams should begin designing and testing as early as possible.

2. Make Gradual Changes:

Try to modify only one component or design feature at a time. Making too many changes simultaneously can introduce unexpected problems and make it difficult to identify their root causes.

3. Test – Analyze – Improve:

After completing the initial prototype, teams should assemble and test the mechanisms to verify whether they function as expected.

Any errors, weaknesses, or inefficient design choices should be identified and analyzed before making improvements.