If you’re into 3D printing, chances are you have a bunch of half-used filament spools lying around. You’ve also probably collected sample packs from filament companies, but they’re not enough for a full print. So what do you do with them?
Enter the Sunlu FC-01 Filament Connector, a tool designed to join pieces of filament together so you can use every last bit. I bought this with my own money to see if it really works, and after testing it, I’ve got some thoughts. Let’s dive in!
What is the Sunlu FC-01?
The Sunlu FC-01 is a compact device that fuses two filament ends together, creating a continuous strand that can be used in any 3D printer. It’s powered via USB and has a built-in heating element to melt and join filaments.
I’ve seen mixed reviews about this tool—some people love it, others find it tricky to use. From what I gathered, there’s a learning curve, but once you get the hang of it, it works well.
What’s in the Box?
Inside the Sunlu FC-01 package, you’ll find:
• The filament connector unit
• A USB power cable
• PTFE connector tubes
• Instructions
The USB power option is convenient, but I wish they had used USB-C instead of the older-style connector.
How to Use the Sunlu FC-01
Using this tool is pretty simple, but getting a strong bond takes practice. Here’s how it works:
1. Power it on and set the temperature for your filament type.
2. Cut the filament ends at an angle to maximize surface contact.
3. Insert both filament ends into the connector, aligning them over the heating element.
4. Press them together as the unit melts the plastic.
5. Let it cool for 15 seconds, then trim the excess.
At first, I struggled a bit, but after following the instructions correctly, I got a solid, smooth weld that passed through a PTFE tube without issues.
Testing the Welds: Does It Actually Work?
I took eight spools of leftover PLA and fused them into one 200g spool, then added four sample spools to the mix. I was curious to see how this multi-brand PLA fusion would print.
I used Bambu Studio’s general PLA setting, and my slicer estimated a little over 200g of filament.
• First layer: Went down smoothly.
• Print progress: At 62% completion, I noticed the spool was almost empty—meaning the filament estimate was off.
• Solution: I could have welded more filament, but I didn’t want to risk a failed print.
Overall, the print came out great, but I did encounter a few issues. Out of 12 welds, 4 failed, mostly because the welds were too thin in certain areas. The success rate was 66%, which isn’t bad for a first attempt.
Does the Sunlu FC-01 Replace an AMS?
If you have a Bambu Lab AMS (Automatic Material System), you might be wondering if this tool is necessary. While the AMS allows filament auto-swapping, it can’t handle small sample spools or random leftover filament. That’s where the FC-01 shines.
Even if you have an AMS, this tool lets you merge old filaments into something usable. If your printer doesn’t have an AMS, this is a great way to reuse filament and reduce waste.
Final Thoughts: Is the Sunlu FC-01 Worth It?
Yes! For around $50, this tool helps extend the life of leftover filament, saving money and reducing waste.
Pros:
✔ Saves money by using leftover filament
✔ Works well once you learn the technique
✔ Allows multi-color prints without needing an AMS
Cons:
✖ Takes practice to get strong welds
✖ Some initial failures if welds are too thin
✖ Would be better with USB-C
The best part? I got multi-color prints without extra waste! My Gandalf print turned out great, and the butterfly print had a cool “Silence of the Lambs” aesthetic.
Would I use this again? Absolutely. Now that I know how to properly inspect my welds, I expect even better results next time.
📌 BUY THE SUNLU FC-01 FILAMENT CONNECTOR ➡ https://amzn.to/41hRnWo
🔗 Related Videos & Resources: 🎥 [Bambu AMS Filament Auto-Swap Setup] ➡ https://makerbuildit.com/blogs/3d-printing/never-run-out-of-filament-again