Upcycle Your Empty Spools into a Train tunnel! 🚂♻️

Turn your empty filament spools into a modular train tunnel (compatible with Brio, and IKEA LILLABO).

The Parts (see images for reference):

🔹 Main Connecting Body (Male & Female Versions): These pieces extend halfway into the spool core and connect via a simple sliding connector pin. Can be mixed and matched based on your preference.
🔹 Connecting Pin: Slides into pre-made slots to attach the tunnel sections, and correctly align them.
🔹 Spool Connector: A two-part piece (upper & lower) that lets you link spools together to create a longer tunnel. The upper part holds the track inside the spool, while the lower part provides extra stability underneath. Also connected via the connecting pins. Connect as many as you want!
🔹 Tunnel Opening: Clips onto the spool edges for a cleaner look while adding a fun brick wall texture to resemble a real train tunnel entrance!

Spool compatibility

I've uploaded two print profiles—one designed to fit Bambu Lab's spool core and another for Esun's spool core. However, I noticed some variations in Esun spools; while one matched Bambu's core exactly, another had a slightly different size, the second profile has parts that fit the different sized core. Before printing, I highly recommend measuring your spool core diameter to ensure the best fit. If your spool is different, comment the dimensions of the core on this post and I'll create a new print profile that fits yours!

Assembly Tip: 

While the connectors slide in securely, adding a small amount of glue during assembly can help keep everything firmly in place.

Turn it into a fun family project! 🎨

Get your kids involved by helping assemble the tunnel pieces! Let them paint or decorate the spool core to create unique tunnel designs.