German description below.
 
V2:

EN: 
VERSION 2 IS HERE! FINALLY!
I apologize for taking so long. I really don’t know why I kept putting it off… Anyway, thank you for your patience and the countless downloads :)

V2 replaces the entire hub assembly instead of simply extending it, as in V1. 
It comes in two versions: The first is identical to the previous version 1.1 and requires no additional hardware (the v2 files), while the second version is designed for use with a PC4-M6 tube connector, ensuring the tube stays securely in place and can no longer slip out. (The v2 (PC4-M6) files)
I’ve also included inverted versions for both designs, as I realized they’re necessary to ensure proper fitment on the Kobra 3 Max.

I recommend using the Arachne Wall generator with a layer thickness of 0.16 mm or lower for optimal detail resolution.
However, I’ve also tested the model with a 0.2 mm layer thickness and the classic wall generator—and it worked perfectly for me too. PLA or PETG makes no difference; both materials perform well. No supports are required, and I didn’t even need a brim!

DE:
VERSION 2 IS HERE! FINALLY!
I’d like to apologize for taking so long. Honestly, I have no idea why I kept delaying this… But anyway, thanks so much for your patience and all the downloads :)

V2 replaces the entire hub assembly rather than just extending it, unlike V1.
The design is available in two variants: One closely resembles the previous version 1.1 and doesn’t require any extra hardware (the v2 files), while the second variant is tailored for use with a PC4-M6 tube connector—guaranteeing that the tube fits snugly and won’t come loose. (The v2 (PC4-M6) files)
I’ve also included inverted versions for both designs, which are essential for compatibility with the Kobra 3 Max.

For printing, I suggest using the Arachne Wall generator with a layer height of 0.16 mm (or lower) for finer details. That said, I’ve also tested the model with a 0.2 mm layer height and the classic wall generator—and it worked great for me as well. PLA or PETG is entirely up to you; both materials print beautifully. No supports are needed, and I didn’t even require a brim!

V1.1:

EN: 
It was pointed out to me that the model was slightly tilted, which caused a noticeable step when slicing. This issue has now been resolved.

DE: 
I was informed that the model had a slight tilt, resulting in a visible step during slicing. This problem has been fixed.

Original description:

EN:
I was tired of constantly swapping tubes whenever I wanted to use the spool holder on my printer instead of the ACE PRO. So I decided to design a custom solution that keeps all five tubes connected at all times.
(For V1.1 only: I recommend a layer thickness of 0.16 mm (“QUALITY” in the Anycubic Slicer). I cannot guarantee that the part will fit properly with other layer thicknesses, as I haven’t tested them.)

THIS PART DOES NOT SUPPORT PRINTING WITH 5 COLORS!
It simply makes it easier to switch between the ACE PRO and the spool holder on the printer!

DE:
I was fed up with having to swap tubes every time I wanted to use the spool holder on my printer instead of the ACE PRO. So I designed a custom solution to keep all five tubes permanently connected.
(For V1.1 only: I recommend a layer thickness of 0.16 mm (“QUALITY” in the Anycubic Slicer), as I haven’t tested other layer thicknesses and can’t guarantee proper fit and performance otherwise.)

THIS PART DOES NOT ALLOW PRINTING WITH 5 COLORS!
It merely simplifies the process of switching between the ACE PRO and the spool holder on the printer!