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 x 25mm x 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
• Pre-configured: Already set to 25mm x 25mm x 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"

Step 2: Resize the Cube

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

Alternative Methods

• Fusion 360: Create square sketch (25mm x 25mm), extrude to 25mm height
• Tinkercad: Use cube shape, adjust dimensions to 25mm x 25mm x 25mm
• FreeCAD: Create cube with specified dimensions
• Any CAD Software: Simple cube 25mm x 25mm x 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 x 25mm x 25mm cube)
   • Or use the Bambu Studio/Orca Slicer primitive steps above

2. Slicer Settings (Critical):

   • Dimensions: 25mm x 25mm x 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!