Designing a Reliable Game Piece Intake

Every game has game pieces, and every robot needs a way to collect them. A well-designed intake can be the difference between a mediocre and a dominant robot. Let’s break down the key principles.

Types of Intakes

1. Roller Intakes

Use spinning wheels or rollers to pull game pieces in.

Pros:

• Fast collection
• Works while driving
• Can intake from multiple angles

Cons:

• Can be bulky
• May require tuning
• Power consumption

Best for: Balls, cubes, any “rolly” game piece

2. Claw/Gripper Intakes

Use fingers or paddles to grab and hold game pieces.

Pros:

• Precise control
• Low power consumption
• Simple mechanism

Cons:

• Slower collection
• Usually one piece at a time
• Requires precise alignment

Best for: Cones, items requiring precise placement

3. Passive Intakes

Use the robot’s motion to collect pieces without additional motors.

Pros:

• No motor needed
• Always ready
• Lightweight

Cons:

• Less reliable
• Requires specific approach angles
• Limited control

Best for: Simple game pieces, weight-limited robots

Key Design Principles

Compliance is King

Rigid intakes fail when game pieces aren’t perfectly positioned. Add compliance (flexibility) to your design:

• Compliant wheels - Flex wheels, surgical tubing, foam
• Spring-loaded arms - Allow the intake to adapt
• Floating geometry - Pivoting mounts

Over-Constrain for Consistency

Once a game piece enters your intake, it should travel a consistent path:

• Guide rails keep pieces centered
• Multiple contact points prevent rotation
• Funnel geometry corrects misalignment

Speed Matters (But So Does Control)

Balance speed and control. A blazing-fast intake is useless if it spits pieces out the other side.

Tips:

• Use different wheel speeds for intake vs. indexing
• Add sensors to detect piece presence
• Implement software speed control

Wheel Selection Guide

Wheel Type	Grip	Durability	Best For
Compliant wheels	High	Medium	Soft game pieces
Flex wheels	Very High	Low	General use
Surgical tubing	High	Low	DIY solution
Mecanum rollers	Medium	High	Indexing
Omni wheels	Low	High	Sorting
Foam wheels	Very High	Low	Delicate items

Geometry Considerations

Intake Angle

The angle at which your intake contacts the ground affects performance:

• Shallow (0-15°): Easier to drive into pieces but may miss short ones
• Medium (15-30°): Good balance for most game pieces
• Steep (30-45°): Better for tall pieces, harder to approach

Roller Spacing

The gap between rollers should be:

• Slightly smaller than the game piece for compression grip
• Large enough to not jam
• Consistent throughout the path

Vectoring

Angle your rollers to move pieces in a specific direction:

• Inward angle → centers pieces
• Upward angle → lifts pieces into robot
• Combine both for optimal flow

Motor Selection

Consider these factors when choosing intake motors:

1. Speed - How fast do you need the intake?
2. Torque - Can it overcome resistance from game pieces?
3. Stall protection - What happens if it jams?

Recommended motors for FTC:

• Core Hex Motor (simple, low power)
• goBILDA 5202/5203 series (versatile)
• REV HD Hex (high torque option)

Testing Your Intake

Before you finalize, test these scenarios:

✅ Single piece, perfect alignment
✅ Single piece, offset left
✅ Single piece, offset right
✅ Two pieces simultaneously
✅ Damaged/bent piece
✅ Piece on its side
✅ High-speed approach
✅ Reverse direction (outtake)
✅ Continuous operation (10+ cycles)

Common Failure Modes

1. Jamming - Pieces get stuck between rollers

   • Fix: Add more compliance, adjust spacing

2. Piece ejection - Pieces fly out after intake

   • Fix: Add top roller, reduce speed, add backstop

3. Inconsistent centering - Pieces enter crooked

   • Fix: Add guide rails, use vectoring

4. Motor stalls - Intake can’t overcome resistance

   • Fix: Gear down, use stronger motor, reduce friction

5. Slipping - Wheels don’t grip game piece

   • Fix: Use grippier material, add compression

Iteration is Everything

Your first intake design probably won’t be perfect. Plan for iteration:

• Use quick-swap mounting
• Keep spare parts ready
• Document what works and what doesn’t
• Get driver feedback

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A reliable intake gives your team confidence. Work on it until it’s boring—that’s when you know it’s good.