Statapult Simulator - Tutorial (Print Version)

🎯 STATAPULT SIMULATOR

Complete User Tutorial

© 2025 KEEPLEAN Educational Tools | Toufik Dakhia LSS Master Black Belt

📖 How to Use This Tutorial:
  • Print: Click the blue button (top right) → Print or Save as PDF
  • Navigate: Use browser Find (Ctrl+F) to search topics
  • Practice: Follow along with the simulator open

📋 Table of Contents

  1. Introduction
  2. Quick Start (60 seconds)
  3. Interface Overview
  4. The 3 Factors (RB, Angle, Pin)
  5. Control Buttons
  6. Running Experiments
  7. Understanding Results
  8. Exporting Data
  9. DOE Applications
  10. Practical Examples

1. Introduction

What is the Statapult?

Statapult is a catapult simulator used to teach Design of Experiments (DOE) principles. By adjusting 3 factors (Rubberband, Angle, and Pin Position), students learn how different parameters affect the launch distance.

🎯 Learning Objectives:
  • Understand how process factors affect output (distance)
  • Learn to design and execute factorial experiments
  • Identify main effects and interactions
  • Apply statistical analysis to experimental data
  • Optimize parameters for maximum performance

Simulator Capabilities

Feature Description
⚙️ 3 Factors Rubberband (2 levels), Angle (100-180°), Pin Position (2 levels)
🎬 Animation 2-phase realistic catapult motion (swing + parabolic flight)
📊 Physics-based Projectile motion with gravity and realistic variability
📈 History Tracking Complete experiment log with all parameters and results
📉 Statistics Total runs, average distance, full data table
📥 Export Excel (.xls) and CSV data export

The DOE Connection

The Statapult simulator is perfect for teaching:

  • Full Factorial Designs: Test all combinations (2³ = 8 runs)
  • Main Effects: How each factor influences distance
  • Interactions: When factors depend on each other
  • Optimization: Finding the best settings
  • Variability: Understanding process repeatability

2. Quick Start (60 Seconds)

✨ Follow these steps to run your first experiment:
Step 1: Select Factor A (Rubberband) → Choose RB = 2
Step 2: Set Factor B (Angle) → Drag slider to 140°
Step 3: Select Factor C (Pin Position) → Choose Pin = 1
Step 4: Click ▶️ LAUNCH
Step 5: Watch the animation (1.8 seconds):
  • Phase 1: Arm swings back (0.3s)
  • Phase 2: Ball flies in parabolic arc (1.5s)
Step 6: Check your results:
  • Distance appears below canvas
  • Experiment added to History table
Expected Results:
  • Distance: ~280-320 cm (varies due to realistic randomness)
  • Run #1 appears in History table
  • Statistics show: Total: 1 run, Average: [your distance]

3. Interface Overview

Three-Panel Layout

┌────────────────────────────────────────────────────────┐
│ Statapult Interactive Simulator                        │
│ © 2025 KEEPLEAN Educational Tools                      │
├──────────────────┬─────────────────────────────────────┤
│                  │                                     │
│  📊 PARAMETERS   │    📈 EXPERIMENT HISTORY            │
│     (35%)        │         (65%)                       │
│                  │                                     │
│  Factor A: RB    │  Run │ RB │ Angle │ Pin │ Distance │
│  ○ 1  ⦿ 2       │   1  │ 2  │ 140°  │ 1   │ 287 cm  │
│                  │   2  │ 1  │ 150°  │ 2   │ 245 cm  │
│  Factor B: Angle │                                     │
│  [━━━●━━━━━]    │  Total: 2 runs                      │
│  140°            │  Average: 266.00 cm                 │
│                  │                                     │
│  Factor C: Pin   │  [🗑️ Clear] [📊 Excel] [📄 CSV]   │
│  ⦿ 1  ○ 2       │                                     │
│                  │                                     │
├──────────────────┴─────────────────────────────────────┤
│                                                        │
│  🎬 ANIMATION PANEL                                    │
│                                                        │
│      🏹 ● →  (catapult and ball)                      │
│  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━│
│  0cm         200cm         400cm         600cm        │
│                                                        │
│  [LAUNCH] [RESET]                                      │
│  Distance: 287.45 cm                                   │
│                                                        │
└────────────────────────────────────────────────────────┘
    
Panel Location Purpose
Parameters Left (35%) Control the 3 factors: RB, Angle, Pin
History Right (65%) View all experiments, statistics, export data
Animation Bottom (full width) Watch launch, see distance, control simulation
💡 Interface Design:
  • Responsive: Adapts to desktop, tablet (35/65 split), and mobile (stacked)
  • Clean: Professional layout with white background
  • Real-time: Arm moves as you adjust angle slider

4. The 3 Factors (RB, Angle, Pin)

Factor A: Rubberband (RB)

Property Description
Type Discrete (2 levels)
Levels 1 or 2
Control Radio buttons (click to select)
Effect Changes elastic force / initial velocity
Impact RB=2 gives longer distances than RB=1 (~30-50 cm more)
How to Use:
  • Click the circle ○ next to 1 or 2
  • Selected option shows as filled circle ⦿
  • Only one can be selected at a time

Factor B: Angle

Property Description
Type Continuous
Range 100° to 180°
Control Slider (drag left/right)
Effect Changes launch trajectory
Optimal Typically around 140-150° (depends on physics)
How to Use:
  • Click and drag the slider handle
  • Angle value updates in real-time (e.g., "140°")
  • The orange catapult arm moves to match the angle
  • Any value between 100° and 180° is valid
💡 Visual Feedback:
Watch the catapult arm move as you adjust the angle. This helps you visualize the launch trajectory before clicking LAUNCH.

Factor C: Pin Position

Property Description
Type Discrete (2 levels)
Levels 1 or 2
Control Radio buttons (click to select)
Effect Changes pivot point / lever arm
Impact Moderate effect, may interact with RB
How to Use:
  • Click the circle ○ next to 1 or 2
  • Selected option shows as filled circle ⦿
  • Only one can be selected at a time

5. Control Buttons

LAUNCH Button

Property Description
Location Bottom panel, left side
Color Blue
Function Start catapult animation and record experiment
Duration 1.8 seconds total (0.3s swing + 1.5s flight)
What Happens When You Click LAUNCH:
  1. Phase 1 (0.3s): Catapult arm swings backward
  2. Phase 2 (1.5s): Ball launches and flies in parabolic arc
  3. Physics calculation: Distance computed based on RB, Angle, Pin
  4. Result display: Distance shown below canvas (e.g., "Distance: 287.45 cm")
  5. History update: New row added to Experiment History table
  6. Statistics update: Total runs and average distance recalculated
💡 Animation Details:
  • Orange catapult arm with visible pivot point
  • Red ball that follows realistic parabolic path
  • Dotted trajectory line showing flight path
  • Motion blur effect during flight
  • Red impact marker where ball lands
  • Distance scale with markers every 200 cm

RESET Button

Property Description
Location Bottom panel, right of LAUNCH
Color Gray
Function Reset all factors to default values
What RESET Does:
  • Factor A (RB) → Set to 1
  • Factor B (Angle) → Set to 140°
  • Factor C (Pin) → Set to 1
  • Catapult arm returns to 140° position
⚠️ Important:
  • RESET does NOT clear the History table
  • All your experiments remain saved
  • Only the factor settings are reset to defaults

Clear Button (🗑️)

Property Description
Location History panel, below the experiment table
Icon 🗑️ Trash can
Function Delete ALL experiments from history
⚠️ WARNING:
  • This action CANNOT BE UNDONE
  • All experiments will be permanently deleted
  • Export your data FIRST if you want to keep it

Export Excel Button (📊)

Property Description
Location History panel, bottom
Icon 📊 Chart
File Format .xls (Excel XML Spreadsheet)
Filename statapult_data.xls
How to Use:
  1. Run at least ONE experiment (button turns green)
  2. Click "📊 Export Excel"
  3. File downloads automatically
  4. Open in Excel, LibreOffice Calc, or Google Sheets

Export CSV Button (📄)

Property Description
Location History panel, bottom
Icon 📄 Document
File Format .csv (Comma-Separated Values)
Filename statapult_data.csv
How to Use:
  1. Run at least ONE experiment (button turns green)
  2. Click "📄 CSV"
  3. File downloads automatically
  4. Open in Minitab, JMP, R, Python, or any text editor
Excel vs CSV:
  • Use Excel (.xls): For quick viewing and basic analysis in Excel
  • Use CSV (.csv): For statistical software (Minitab, JMP, R, Python)
  • Both files contain identical data (Run, RB, Angle, Pin, Distance)

6. Running Experiments

Single Experiment Workflow

Step 1: Configure Factors
  • Choose RB: 1 or 2
  • Set Angle: Drag slider (100-180°)
  • Choose Pin: 1 or 2
Step 2: Verify Settings
  • Check catapult arm position (matches angle)
  • Confirm all factors are as desired
Step 3: Launch
  • Click LAUNCH button
  • Watch 1.8-second animation
Step 4: Record Results
  • Distance automatically displayed
  • Experiment added to History table
  • Statistics updated

Full Factorial Experiment (2³ Design)

The Statapult has 3 factors with 2 levels each. A Full Factorial Design tests all possible combinations:

Run RB Angle Pin Notes
1 1 110° 1 Low-Low-Low
2 2 110° 1 High-Low-Low
3 1 170° 1 Low-High-Low
4 2 170° 1 High-High-Low
5 1 110° 2 Low-Low-High
6 2 110° 2 High-Low-High
7 1 170° 2 Low-High-High
8 2 170° 2 High-High-High
💡 DOE Best Practice:
  • Run all 8 experiments in random order
  • This prevents bias from systematic effects
  • Use a randomization tool or shuffle the order manually

Understanding Variability

Realistic Variation:

The simulator includes ±2% random variability to mimic real-world conditions. This means:

  • Running the same settings twice gives slightly different distances
  • This is NORMAL and REALISTIC
  • In real experiments, no two runs are exactly identical
  • This teaches the importance of replication and statistical analysis

7. Understanding Results

Experiment History Table

Column Description Example
Run Sequential experiment number 1, 2, 3, 4...
RB Rubberband setting used 1 or 2
Angle Launch angle used 140°, 150°, 170°...
Pin Pin position used 1 or 2
Distance Launch distance achieved 287.45 cm

Statistics Display

Statistic Description Example
Total Number of experiments completed "Total: 8 runs"
Average Mean distance across all experiments "Average: 287.45 cm"

Calculating Main Effects

To determine which factors significantly affect distance:

Effect of Rubberband (RB):
Effect = Average(RB=2) - Average(RB=1)

Example:
Average at RB=2: 310 cm
Average at RB=1: 250 cm
Effect = 310 - 250 = +60 cm

Interpretation: RB=2 increases distance by 60 cm on average
        
Effect of Pin Position:
Effect = Average(Pin=2) - Average(Pin=1)

Example:
Average at Pin=2: 285 cm
Average at Pin=1: 275 cm
Effect = 285 - 275 = +10 cm

Interpretation: Pin=2 increases distance by 10 cm on average
        
Effect of Angle:

For continuous factors, plot Distance vs Angle to see the relationship. Typically:

  • Low angles (100-120°): Shorter distances
  • Optimal angle (~140-150°): Maximum distance
  • High angles (160-180°): Decreased distances

Identifying Interactions

What is an Interaction?

An interaction occurs when the effect of one factor depends on the level of another factor.

Example:

  • At Pin=1: RB effect = +50 cm
  • At Pin=2: RB effect = +70 cm
  • Conclusion: RB and Pin interact (effect changes with Pin level)

8. Exporting Data

Export File Contents

Both Excel and CSV files contain the same 5 columns:

Run,RB,Angle,Pin,Distance
1,1,140,1,245.67
2,2,150,2,312.45
3,1,130,2,278.91
4,2,160,1,298.34
...
    

Analysis in Excel

Step 1: Open Data
  • Double-click statapult_data.xls
  • Opens in Excel automatically
Step 2: Calculate Statistics
  • =AVERAGE(E2:E9) for mean distance
  • =STDEV(E2:E9) for standard deviation
  • =MAX(E2:E9) and =MIN(E2:E9) for range
Step 3: Create Pivot Table
  • Insert → PivotTable
  • Rows: RB or Pin
  • Values: Average of Distance
  • Compare means at each level
Step 4: Visualize Effects
  • Insert → Chart → Scatter plot
  • X-axis: Angle
  • Y-axis: Distance
  • Series: Group by RB or Pin

Analysis in Minitab

Step 1: Import CSV
  • File → Open → Select statapult_data.csv
Step 2: Analyze Factorial Design
  • Stat → DOE → Factorial → Analyze Factorial Design
  • Response: Distance
  • Factors: RB, Angle (treat as categorical with 2 levels), Pin
Step 3: Generate Plots
  • Main Effects Plot
  • Interaction Plot
  • Pareto Chart of effects
  • Normal Probability Plot

Analysis in R

# Load data
data <- read.csv("statapult_data.csv")

# Summary statistics
summary(data$Distance)
sd(data$Distance)

# ANOVA
model <- aov(Distance ~ RB * Angle * Pin, data=data)
summary(model)

# Main effects plot
library(ggplot2)
ggplot(data, aes(x=factor(RB), y=Distance)) +
  geom_boxplot() +
  labs(title="Effect of Rubberband")
    

9. DOE Applications

One Factor at a Time (OFAT) - Not Recommended

⚠️ Common Mistake:

Many beginners use OFAT approach - changing one factor at a time while keeping others constant. This method:

  • Requires MORE experiments than factorial design
  • CANNOT detect interactions
  • May lead to suboptimal conclusions
Run RB Angle Pin Notes
1 1 140° 1 Baseline
2 2 140° 1 Change RB only
3 1 160° 1 Change Angle only
4 1 140° 2 Change Pin only

Problem: This gives 4 experiments but misses all interaction information!

Full Factorial (2³) - Recommended

✅ Best Practice:

Full Factorial Design tests all 8 combinations:

  • Requires only 8 experiments
  • Identifies all main effects
  • Detects all 2-way and 3-way interactions
  • Provides complete information

Response Surface Methodology (RSM)

For advanced users exploring the continuous Angle factor:

Run RB Angle Pin
1-4 1 or 2 100° 1 or 2
5-8 1 or 2 130° 1 or 2
9-12 1 or 2 150° 1 or 2
13-16 1 or 2 170° 1 or 2

This allows modeling the curvature of the Distance vs Angle relationship.

10. Practical Examples

Example 1: Beginner Exercise

Objective: Understand basic operation
Run RB Angle Pin Purpose
1 1 140° 1 Baseline
2 2 140° 1 Test RB effect
3 1 140° 2 Test Pin effect
Expected Learning:
  • RB=2 gives noticeably longer distance
  • Pin effect is smaller but still measurable
  • Results vary slightly due to randomness

Example 2: Full Factorial 2³

Objective: Complete DOE analysis
Run RB Angle Pin Expected Distance Range
1 1 110° 1 180-220 cm
2 2 110° 1 230-270 cm
3 1 170° 1 200-240 cm
4 2 170° 1 250-290 cm
5 1 110° 2 190-230 cm
6 2 110° 2 240-280 cm
7 1 170° 2 210-250 cm
8 2 170° 2 260-300 cm
Analysis Steps:
  1. Export data to Excel/Minitab
  2. Calculate main effect of RB: Avg(RB=2) - Avg(RB=1)
  3. Calculate main effect of Pin: Avg(Pin=2) - Avg(Pin=1)
  4. Calculate main effect of Angle: Avg(170°) - Avg(110°)
  5. Create interaction plots (RB × Pin, RB × Angle, Pin × Angle)
  6. Determine optimal settings for maximum distance

Example 3: Optimization Challenge

Objective: Find settings that produce distance > 320 cm
Phase 1: Screening
  • Run 8-experiment factorial (see Example 2)
  • Identify which factors have largest effects
Phase 2: Angle Optimization
  • Fix RB=2 (usually gives longer distance)
  • Test angles: 130°, 140°, 150°, 160°
  • Find the angle that maximizes distance
Phase 3: Confirmation
  • Run 5 replicates at optimal settings
  • Calculate mean and standard deviation
  • Verify consistent performance > 320 cm
Expected Result:

Optimal settings typically around: RB=2, Angle=140-145°, Pin=2

This should yield distances of 310-330 cm consistently

Example 4: Variability Study

Objective: Understand process repeatability
Replicate Settings Purpose
1-10 RB=2, Angle=140°, Pin=1 Same settings, 10 times
Calculate:
  • Mean distance
  • Standard deviation (σ)
  • Coefficient of Variation: CV% = (σ / mean) × 100
  • Min and Max values
  • Range = Max - Min
Expected Results:
  • Mean: ~290 cm
  • Std Dev: ~5-6 cm (≈2% variation)
  • CV%: ~2%
  • Range: ~15-20 cm

This demonstrates the inherent variability in the process, teaching students why replication and statistical analysis are essential.

Troubleshooting Guide

Common Issues & Solutions

Problem Possible Cause Solution
Simulator doesn't display Browser cache issue Hard refresh (Ctrl+F5 or Cmd+Shift+R)
Animation doesn't play JavaScript disabled Enable JavaScript in browser settings
Angle slider doesn't move Click not on handle Click and drag the slider handle specifically
Export buttons are gray No experiments run yet Click LAUNCH at least once first
Download doesn't work Pop-ups blocked Allow pop-ups and downloads for this site
Distance seems wrong Misunderstanding randomness ±2% variation is normal; run multiple replicates
History table not visible on tablet Old version Use version with 35/65 column split
RESET doesn't clear history Working as designed RESET only resets factors; use Clear to delete history

Quick Reference Card

Default Settings

Parameter Value
Factor A (RB) 1
Factor B (Angle) 140°
Factor C (Pin) 1

Key Shortcuts

Action Method
Launch experiment Click LAUNCH button
Reset to defaults Click RESET button
Clear all data Click 🗑️ Clear button
Export to Excel Click 📊 Export Excel
Export to CSV Click 📄 CSV

Typical Distance Ranges

Settings Expected Distance
RB=1, Low Angle 180-230 cm
RB=1, Optimal Angle 240-280 cm
RB=2, Low Angle 230-280 cm
RB=2, Optimal Angle 290-330 cm

DOE Formulas

Main Effect (2-level factor):
Effect = Average(High) - Average(Low)
Interaction Effect (2-way):
Interaction = [Effect of A at B(high)] - [Effect of A at B(low)]
Number of Runs (Full Factorial):
Runs = k^n
k = levels per factor, n = number of factors
For Statapult: 2³ = 8 runs (with 2 angle levels)

Statistical Measures

Mean:
x̄ = Σx / n
Standard Deviation:
σ = √[Σ(x - x̄)² / (n-1)]
Coefficient of Variation:
CV% = (σ / x̄) × 100
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