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November 2025 Challenge

"Wait, This Was Printed? How Are There No Layer Lines?"

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!

Challenge Details

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, 0.4mm nozzle, no post-processing)
   • Winner is determined solely by smoothness of surface and minimal layer line appearance

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
• Nozzle Verification: Must be printed with 0.4mm nozzle
• Settings Documentation: Share your winning settings (layer height, temperature, speed, cooling, techniques)
• Process Notes: Brief description of your approach

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)

Creating the Cube Model

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

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, Y, and Z to 25mm

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

Awards & 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

Full challenge details: November 2025 Challenge Repository