♻️ Spool QuickLock System – Reusable Cardboard Spool Adapter for Bambu Lab Refills

Give new life to your old cardboard filament spools with this 3-part adapter system, designed to make them reusable and fully compatible with Bambu Lab refill coils. This modular solution lets you convert a non-reusable spool into a sturdy, refillable one using just a few printed parts and some glue.

🛠️ Includes:

• Spool QuickLock 1 – Top locking ring
• Spool QuickLock 2 – Threaded insert with locking surface
• Spool QuickLock 3 – Threaded bottom ring
• Spool QuickLock 4 – Optional shaping tool to help round the cardboard core

🔧 Key Features:

• Designed to work with cardboard spools, like PolyTerra PLA and similar ones.
• Makes your spool refill-compatible and reusable
• Easy to print, assemble, and customise
• Helps reduce waste and extend spool life

📘 Assembly Instructions:

• Step 1: Take your cardboard spool and separate it into its 3 components: the two side discs and the central cylinder
     

   

• Step 2: Measure the cylinder’s circumference with a flexible tape. Trim it to approximately 26.5 cm.
   

   

• Step 3: Measure the height of the cylinder. It must be at least as tall as the cardboard core of a Bambu Lab refill (approx. 59.80 mm). If shorter, add a spacer; if taller by more than 2–3 mm, trim it.
   

• Step 4: Reform the cylinder into a round shape, avoiding sharp folds. Use an empty refill core or print Spool QuickLock 4 as a guide for shaping. Insert the cylinder halfway into the guide for step 5.

   
   

• Step 5: Apply glue to the side face of Spool QuickLock 1 and insert it into the cardboard cylinder, aligning it flush with the top edge. Push the cylinder fully into the shaping guide.

  

   

• Step 6: Rotate and glue the bottom edge between Spool QuickLock 1 and the cylinder. More glue = more strength.
  
   
• Step 7: Apply glue to the side face of the Spool QuickLock 3 and insert it into the opposite end of the cylinder, ensuring it is flush with the edge.
  
   

• Step 8: Apply glue over the top surface and threads of the Spool QuickLock 3, as well as to the exposed cardboard. Screw in one of the spool’s side discs and glue it in place. 

  

   

• Step 9: Rotate and glue the bottom edge between Spool QuickLock 3 and the cylinder. More glue = more strength.
  
   
• Step 10: Apply glue to the threads of Spool QuickLock 2, screw in the other side disc, and glue it from the outside too.
  
   
• Step 11: Let the glue dry completely.
   
• Step 12: Remove the shaping guide and wrap the cylinder with something thin (e.g. masking tape) to reinforce it.
   
   

• Step 13: Your spool is ready. Fill it, close it, and use it!

  

⚠️ Disclaimer:
Dimensions may vary depending on your spool. This model was designed specifically for the PolyTerra PLA cardboard spool – always verify measurements before printing.
Cardboard spools, as they are, may not be optimal for AMS systems.
Depending on the glue used, the spool may or may not be suitable for the drying process. I did not try.
Credits for the quicklock mechanism: [https://youtu.be/ghvnNWPTwpE?si=4oxes66hdE18Q21B](https://youtu.be/ghvnNWPTwpE?si=4oxes66hdE18Q21B)