Ethernet Cable Reel - RJ45 Extension Spool

Turn a spare SUNLU filament spool into a clean, functional ethernet extension reel - just like those retractable extension cord reels, but for CAT5/6 cable.

A dedicated hole in the spool hub accepts a standard RJ45 keystone connector (the pass-through type commonly found on AliExpress).

Assembly uses hardware, not friction:

• M3 × 12mm screws
• M3 × 4 × 5mm heat-set inserts

This means the two spool halves open and close reliably every time - no fighting with tight friction fits. Of course it's possible to do it without inserts and screws. 

 

Drill template included: A dedicated template guides an 8mm drill bit to create the dowel holes in both connector plates, so the spool spins freely on the stand.

The road to get here: This didn't come together on the first try. Several prototypes came before this release - each one teaching a lesson about tolerances, connector fitment, spool alignment, and how to make assembly actually enjoyable rather than a battle. The insert-and-screw approach in particular went through a few iterations before landing in its current form. Every failed print was worth it.

Print files included:

• Left side
• Right side
• RJ45 connector mount
• Handle connector
• Handle
• Drill template

Hardware required:

• M3 × 12mm screws (x3)
• M3 × 4 × 5mm heat-set inserts (×3)
• 1× SUNLU filament spool (empty) (see image below)
• RJ45 keystone connector (example: https://www.aliexpress.com/item/1005010685008464.html)
• 8mm drill bit

The support SUNLU spool

Put the drill template on the spool and drill a hole. Preferred where the sticker is, since you have more space.

Currently designed around the SUNLU spool and tested on Bambu Lab P2S. I printed this with the aux fan off.

A1 Mini support, compatibility with other spool brands, and a fully self-contained version (no upcycled spool required) are all being explored.