It's a remix of HugoHuge's filament holder.
The bracket is built for a 2040 profile.
The bracket can be mounted on the rear left or rear right frame.
However, I have installed three additional profiles (1x2040 / 2x 2020 - 406mm). This hides the filament roll in the frame.
The power supply and the DuetWiFi card are in the right rear corner.
The mount is so big that even 1kg filament rolls are safe.
Optimized STL files in version 2
Step files added for your own modification.