The Short-Y – Compact PTFE Y-Splitter PC4-M10

The Short-Y – Compact PTFE Y-Splitter (PC4-M10) – Only 50mm!
Compact yet with a friction-free path

I tested several splitters; the best-performing ones measured about 75 mm, while shorter models created too much friction and caused under-extrusion.
This length necessitated either a tight AMS tube bend radius or adding an extra tube and connector, which increased filament loading times

The Short-Y is a compact splitter (50 mm) with an internal path engineered for smooth flow while minimizing overall length.
As shown in the cross-section view, the filament follows just one large-radius bend instead of two, unlike most other models, which greatly reduces friction

The Short-Y works with “pass thru” PC4-M10 connectors for Bowden PTFE tubes.
Tubes must be fully inserted to the bottom of the splitter, and then the connectors should be tightened firmly for proper support and continuous filament guidance

If you prefer printing your own connectors like me, I've designed compact PC4-M10 compatible models available here
These are the ones I use with the Short-Y

I've also designed a dedicated Short-Y mount: Fix-Y
The Fix-Y mount wraps perfectly around the Short-Y but is easily removable.
It mounts to the printer via an M3 screw hole and four 5x2 mm magnets, which are sufficient to hold it on the rear of a Bambu Lab X1C. I assume it works for other printer models as well

Find all my accessories for your printer here:

ADVANTAGES:

• Optimized, smooth, jam-free filament transport
• Allows use of an external spool without removing the original PTFE tube
• FDM printing optimized, easy to print
• Compatible with “pass thru” PC4-M10 connectors (and my printable ones)
• Free download, near-zero cost if printing connectors
• Ultra-compact, fits within the printer's footprint
• Maintains a large bend radius for the AMS-supplied PTFE tube
• The Short-Y + mount attaches to my X1C rear with magnets, no screws needed

TIPS:

• Orientation: print vertically, with the outlet side down
• Enable supports only on the two small pre-selected areas; they remove easily
• Tested material: basic PLA, 0.4 mm nozzle
• 0.12 mm layer height for a precise internal path and optimal filament glide
• Cut PTFE tubes straight and cleanly at 90°
• Insert each tube fully until it stops inside the Short-Y
• The outlet tube inserts less deeply than the inlet tubes but must protrude through the connector
• Tighten connectors firmly but not excessively (printed part)