Ultimate A1/A2L BMCU Spools Top Rail / Desk Mount

This is a custom mount for the BMCU on the Bambu Lab A1/A2L and up to 4 filament spools, designed to attach directly to the printer’s top rail.
The top rail clip is inspired by @Carnat’s model, while the rest of the design is entirely original, focused on better balance, rigidity, and ease of printing and assembly.

🔧 Features:

• Top rail clip – mounts securely with no screws or extra hardware
• Holds up to 4 spools
• Integrated BMCU mount with precise alignment
• Modular parts for easy printing even on smaller build plates
• Snap-fit joints and alignment pins for clean, easy assembly
• Glue recommended for extra rigidity (especially for the spool axle caps, which require glue to stay in place)
• Smooth, professional design with an embossed Bambu Lab logo
• !NEW PROFILE! Desk Support Base to place it on your desktop without mounting it on your A1/A2L

🧱 Assembly & Mounting Instructions:

1. Print all parts (recommended layer height: 0.2 mm or finer).
2. Assemble the upper section:
3.  
   • The top part includes two hidden holes underneath for securing the BMCU using two M4 self-tapping screws.
     
4. Mount the upper section onto the central column using two additional M4 self-tapping screws inserted through the side holes.
   • ⚠️ Do NOT glue this joint — it must stay detachable to allow access to the hidden screw holes under the top piece for BMCU removal or maintenance.
5. Once the structure is secured, assemble the spool axles and glue the end caps (they won’t hold otherwise).
6. Finally, clip the whole unit onto the A1/A2L top rail until it locks in place.

🧠 Recommended Add-ons:

For optimal balance and usability, it’s highly recommended to pair this mount with:

• A Low Friction Spool Holder like @TurboGlenn's Model
• A rear support such as @KrystoCraft’s AMS Lite A1 Top Mount Support
• A PTFE tube insert guide like @EngineerLab’s model

These additions improve printer stability and make filament loading much smoother.

💡 Keep your BMCU and up to 4 filament spools neatly organized, save desk space, and give your A1/A2L a clean, professional look with this modular top-mounted setup.