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07Week 7

Advanced Mechanisms

Grab it, lift it, place it, every single time.

A drivetrain gets your robot around the field, but mechanisms are what actually score. This week you will learn how intakes, grippers, lifts and arms work, why torque and gear reduction matter, and how to choose between ideas with a weighted decision matrix. You will finish by prototyping a mechanism quickly and proving how reliable it is with a cycle test.

4
Lessons
8 team hours
Estimated time
5
Learning objectives
Start lesson
Game of the week

Pick the gears

A motor has to lift a load on a spool. Too little reduction and it stalls, too much and it is painfully slow. Find a gear pair that lifts in time.

How to play
  1. 01Choose the motor (driving) gear and the output (driven) gear.
  2. 02Ratio = driven teeth ÷ driving teeth. A higher ratio gives more torque but less speed.
  3. 03Press Test. Solve a level on the first try for 2 points, later for 1.
Recommended video

Lessons by Brogan M. Pratt

Video tutorials from the FTC community. Watch them alongside this week's lessons.

Code

Full Course: How to Program Any Pivoting Robot Arm with PID and Feedforward

YouTube

Video by Brogan M. Pratt

Educational content shared with permission. Brogan M. Pratt is not officially affiliated with or endorsing Rookie Academy or FIZMAT ROBOTICS #28061.

Original video: youtube.com/@BroganMPratt

Mechanisms

Stop Using the Wrong Intake Wheels

YouTube

Video by Brogan M. Pratt

Educational content shared with permission. Brogan M. Pratt is not officially affiliated with or endorsing Rookie Academy or FIZMAT ROBOTICS #28061.

Original video: youtube.com/@BroganMPratt

Team assignment

Prototype and evaluate a useful robot mechanism

Pick one job your robot must do with a game element (collect it, lift it, or place it). Compare at least three mechanism ideas with a weighted decision matrix, build a quick prototype of the winner, and cycle test it at least 20 times. Use the results to decide what to change in the next version. Treat any size, extension or motor limits you mention as general examples and check the current official Competition Manual.

Deliverables

Tick items off as your team completes them.

0/4

Learning objectives

  • Explain how roller intakes, compliant wheels and servo claws grab game elements
  • Compare continuous and cascade rigging for linear slide lifts
  • Estimate the torque an arm needs at the shoulder and choose a sensible gear reduction
  • Select a mechanism using a weighted decision matrix
  • Build a quick prototype and measure its success rate with a cycle test

Required materials

  • Robot kit structure, motors, servos and hardware (goBILDA, REV or similar)
  • Cardboard, zip ties, hot glue gun, tape and a few wooden dowels or scrap shafts
  • Compliant wheels or surgical tubing (if available)
  • Braided string or a timing belt for slide rigging (if building a lift)
  • Safety glasses, a box cutter with a cutting mat, and a ruler or tape measure
  • Kitchen or luggage scale for weighing parts
  • A practice game element (or a similar-sized object) and a stopwatch
  • Engineering notebook or a shared spreadsheet

Expected outcomes

  • Students can name the main mechanism types and describe what each is good at
  • Students can explain why holding a lift or arm in place takes continuous effort
  • Students can calculate a rough shoulder torque and relate it to gear ratio
  • Students can run and document a weighted decision matrix
  • Students can design, run and record a cycle test with a clear success rate

Knowledge check

16 questions across this week's lessons. Your best score for each lesson is saved.

  • Intakes and Grippers–/4
  • Lifts and Linear Slides–/4
  • Arms, Torque and Gear Reduction–/4
  • Choosing, Prototyping and Testing Mechanisms–/4

Completion checklist

Tick items off as your team completes them.

0/6