This is a modification of https://www.thingiverse.com/thing:2733649, thanks to the author for providing the idea.
The parts are for both the right and the left side of the printer, in the beginning I was using the left holders from the link above, but then I discovered that they are too close to the petsfang in the higher part of the printer, therefore I modified them. I also needed more space on the right of the frame for the direct feed petsfang I mounted, and I decided to combine it with the support for z axis, which I took from here: https://www.thingiverse.com/thing:2739921, an upgrade of Cater’s https://www.thingiverse.com/thing:2569379 (again thanks so much for your work).
The design is not fantastic, I was designing something for the first time using 3d builder and Meshmixer, feel free to improve it if you wish.
But it works, as you can see from the pictures. The pictures are updated with the latest version with the only exception of the upper right holder (didn't have the time to print the latest version yet), but the STL files attached are already the latest version, improved.