A New Concept Expandable Y-Splitter, Compact, Universal and Easy to Maintain

Description

In order to use my Qidi Box to print in multi-color while keeps at least one channel for external manual filament feeding. I personally have printed many Y-Splitters that I found on the Internet. Most of them were failed on printing process, very few of them survived. I even bought two 4 to 1 from BambuLab. Didn't really satisfy with all of them. I decided to design one by myself.

Introducing an unique designed new concept universal 3-way Y-Splitter.

• Expandable: Thanks to its unique design, you can now easily expand the splitter to 3 to 1 , 4 to 1 , 5 to 1 , 6 to 1, 8 to 1 or even more as your wish. Especially for people who have Multi-Color 3D Printing system. You are no longer to be frustrated on how to add a new filament tube in your system. 

• Compact & Light: 50mm in length. Easy to intergrate with your current system especially where the space is critical. I didn't choose to use the regular PC4 pneumatic connector. It's big, too heavy and takes more space. And to match the thread on a 3D printing model is also a pain as well. I chose a type of Bowden Tube Clamp, a compatible BambuLab's filament feeding connector, which is much lighter and compact. And more importantly user friendly.

• Versatile: There is another special design I have made which you don't even need special connectors to hold the filament tubes. You can use cheap rubber rings to hold the tubes. 

• Easy to Maintain: It's easy to operate whenever you encounter a problem or just want to add a new splitter. You just simply uncrew and open it.

• Easy to Print: It is painful to print the Y-splitter in one piece. You have to make sure your printing is perfect since you never know what's gonna happen inside the splitter. That's one of the reasons I made it two seperated pieces which it's not only easy to print but also easy to polish the inside slots if there were some printing flaws.

Show Time

There are two types of the Y-splitter, Female-Male Type and Female-Female Type.

By playing around the female and male ends, we can easily expand them to have more input ports as you can see from the below diagrams. 

Thanks to the octagonal design of the male-head, the input ends of the splitter can be adjusted in different angles to have different directions. 

Here is how the inside structure looks like. It also demostrates how does it look like after the tubes are inserted. 

A closeup inside look on how to put 3 of them together to make one 4 to 1 splitter. And I have designed slots on the both side of the body as you can see in the diagram. These side slots could be used to design some sort of clips to hold or mount the splitter on the wall or some where as your wish.

The diagram below shows you one of the important values you need to know when you try to expand the splitter. You need to cut a piece of short tube to connect (bridge) them which is 25mm in length. 

Splitters I am using in real scenario. 

 BOM

BOM - Optional Hardware

Tips

• The 4x2.5mm PTFE tube is recommended to use. However 4x3mm is acceptable, since bigger inner diameter of the PTFE tube could help reducing the impact of friction if you have a long tube. 

• The Y-Splitter has two parts, PartA and PartB. The PartA has three little positioning posts. The PartB has the holes for Heat Insert Nuts. You won't miss it.

• Unlike other one-piece stlye Y-Splitters, there are really not much requirements on printing parameter settings. Personally I print with PETG, 0.4 nozzle, 0.2 layer hight, 4-walls, as usual. The only thing needs to mention is the small printing support which was pre-design for the Octagon-Male-Head. Slice the support (in Objects) seperately with 1-wall, 0-top shell layer, 2-bottom shell layer, 40~50% Grid infill. That's it.

• If you have gone through the diagrams above, the assembly is pretty straight forward. No much to say either.

Updates

Feb 25, 2026

Uploaded v0.2 Models. Increased the diameter of the inner filament slot to 2.4mm, hoping it could improve the smoothness. 

Added a little bushing model (8.9x5.7x2.6mm) for some of the clamps don't come with the rubber end. Thanks to VAL INOK @VALINOK_2305597 contribution! 

Place Models in Slicer

Placing F-F Y-Splitter

Placing F-M Y-Splitter

Enjoy!