This is more like a collection of different parts I've designed and redesigned since I have this 3D printer, I simplified most of them in these 4 parts. This set replaces the original bowden tube, both ends coupling, and the original feeder support; but it's necessary a cut of 33mm cut of the PTFE teflon tube in the hotend part. These couple were a big pain to me because they broke more frequently than desired, leaving small metallic debris that ended in the nozzle. Most of parts needed for assembly are already included with the FLSUN Cube printer set:

M3 screws, nuts and washers. For the "lever" and "reinforce" parts you need 20mm long M3.
Nema 17 drive.
The original hobbed pulley.
33mm long 4mm diameter teflon tube.
Spring, I don't know its force, it's a standard one in 3D printing, about ~10mm diameter and ~20mm long.
608zz bearing. The standard "fidget spinner bearing".

This mod is a perfect improve for printing with flexible materials like TPU in this printer, since it crops the feeder to nozzle travel to a few cm, and shrinks the gap between the hobbed pulley and the filament conduct. It's recommended to re-calibrate your retraction setup after installing it. This setup fits well with other design of mine: this fan duct. These parts may work for similar 3D printers, but I cannot guaranty that.

I spend part of my time making these models, letting them available and free for everyone. If you want to support my work, you can contribute with me here:

"Direct drive extruder" results