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# November 2025 Challenge: "Wait, This Was Printed? How Are There No Layer Lines?"

## Challenge Overview

Can you achieve the smoothest, most layer-line-free surface finish possible? This challenge pushes your printer tuning, slicer settings, and material knowledge to the limit. The goal is simple but difficult: create a 25mm cube with 2 walls and no top that looks so smooth, people question whether it was actually 3D printed!

This challenge focuses on:

- Surface finish quality and smoothness
- Proper printer calibration and tuning
- Optimal slicer settings for layer adhesion
- Material selection and temperature control
- The art of making layer lines disappear

## Challenge Rules

### Materials & Constraints

- **Filament**: 3D Fuel filament (any type: PLA+, Pro PLA+, PCTG etc.)
- **Nozzle Requirement**: Must use a 0.4mm nozzle (REQUIRED)
- **Estimated Filament Usage**: Approximately 3 grams (for reference only)
- **Model Specification**:
  - **Dimensions**: Exactly 25mm × 25mm × 25mm cube (REQUIRED)
  - **Wall Count**: Exactly 2 walls (no more, no less) (REQUIRED)
  - **Top Layers**: 0 (no top surface)
  - **Bottom Layers**: Standard (as needed for proper adhesion)
  - **Infill**: 0% (hollow interior)
- **Print Mode**: Standard FDM/FFF printing (no resin printing)

### Competition Categories

- **Smoothest Surface**: Best overall surface finish with minimal visible layer lines straight off the printer
- **No post-processing allowed** - cubes must be judged as-printed

### Judging Criteria

1. **Layer Line Visibility** (100%): The appearance and visibility of layer lines - less visible is better
   - All cubes must meet basic challenge requirements (25mm cube dimensions, exactly 2 walls, no post-processing)
   - Winner is determined solely by smoothness of surface and minimal layer line appearance
   - **Tiebreaker**: If two prints are too close to differentiate, the fastest print time wins

### Submission Requirements

- **Physical Model**: Bring your printed 25mm cube to the December meetup for judging
- **Dimension Verification**: Must be exactly 25mm x 25mm x 25mm
- **Wall Count Verification**: Must show exactly 2 walls when inspected
- **Print Time**: Record and report your total print time (used as tiebreaker if needed)
- **Documentation**: Include photos showing:
  - Close-up surface details
  - Overall cube appearance
  - Cross-section or wall thickness (optional)
- **Settings Documentation**: Share your winning settings:
  - Layer height
  - Print temperature
  - Print speed
  - Cooling settings
  - Any special techniques used
- **Process Notes**: Brief description of your approach

### Evaluation Process

- **Dimension & Wall Check**: Verification of 25mm cube dimensions and exactly 2 walls (must pass to be eligible)
- **Visual Inspection**: Expert panel examines layer line visibility under good lighting
- **Community Voting**: People's choice for most impressive result

## Prizes & Recognition

### Awards

- **Smoothest Surface Winner**: Best layer-line elimination straight off the printer
- **People's Choice Award**: Community favorite

### Documentation

- Winner photos for social media sharing
- Settings profiles shared with community
- Technique documentation for learning

## Timeline

- **Challenge Announcement**: November 12, 2025 (at November meetup)
- **Submission Deadline**: December 10, 2025 (at December meetup)
- **Judging Period**: December 10, 2025 (during December meetup)
- **Winner Announcement**: December 10, 2025 (end of December meetup)

## Model Creation Instructions

### Using the Provided Model

**Download the pre-configured cube:**

- **File Location**: [Challenge Files/November2025/Cube.3mf](../../Challenge%20Files/November2025/Cube.3mf)
- **Pre-configured**: Already set to 25mm × 25mm × 25mm with 2 walls and no top
- **Ready to slice**: Import into your slicer and adjust settings for your printer

### Creating the Cube Model from Scratch

#### Using Bambu Studio

**Step 1: Add Primitive**

1. Open Bambu Studio to a new project
2. Right-click on the build plate
3. Select "Add Primitive"
4. Select "Cube"

![Adding Cube Primitive](../../.images/Nov-Comp-ss1.png)

**Step 2: Resize the Cube**

1. Click to resize the cube
3. Set X to 25mm and Y and Z should also set to 25mm(If uniform scale cause issue you can uncheck)

![Resizing Cube Dimensions](../../.images/Nov-Comp-ss2.png)

#### Alternative Methods

- **Fusion 360**: Create square sketch (25mm × 25mm), extrude to 25mm height
- **Tinkercad**: Use cube shape, adjust dimensions to 25mm × 25mm × 25mm
- **FreeCAD**: Create cube with specified dimensions
- **Any CAD Software**: Simple cube 25mm × 25mm × 25mm
- **Use provided file**: Open `Challenge Files/November2025/Cube.3mf` directly

### Basic Cube Setup

### Slicer Configuration

1. **Create or Download Model**:
   - Use the provided `Challenge Files/November2025/Cube.3mf` file
   - Or create using any CAD software (25mm × 25mm × 25mm cube)
   - Or use the Bambu Studio/Orca Slicer primitive steps above

2. **Slicer Settings** (Critical):
   - **Dimensions**: 25mm × 25mm × 25mm
   - **Wall Count/Perimeters**: 2
   - **Top Layers**: 0
   - **Bottom Layers**: 3-5 (as needed)
   - **Infill**: 0%
   - **Layer Height**: Your choice (hint: smaller = smoother, but slower)

3. **Tips for Success**:
   - **Lower layer heights** (0.1mm-0.12mm) help reduce visible lines
   - **Slower speeds** improve surface quality
   - **Temperature tuning** is critical for layer adhesion
   - **Linear advance/pressure advance** can help with consistency
   - **Proper cooling** prevents warping without sacrificing layer bonding
   - **Material choice** matters - some filaments naturally produce smoother surfaces

### Advanced Techniques to Consider

- **Slicer Tricks**:
  - Adjust line width for better wall fusion
  - Experiment with different seam positions
  - Use variable layer heights if supported
  - Try different acceleration/jerk settings

- **Material Selection**:
  - Experiment with different 3D Fuel filament types
  - Colors can also give different appearance levels

### What NOT to Do

- Do not exceed 2 walls
- Do not add a top surface
- Do not deviate from 25mm cube dimensions
- **No post-processing allowed** (no sanding, heat treatment, chemical smoothing, etc.)


Good luck creating the smoothest cube possible! May your layer lines vanish into nothingness!
