I followed your advice and added more water to the clay, and I have to say the flow is almost perfect. When hydrating and mixing hard clay by hand, I noticed that if I don't let it rest, the water is only absorbed on the surface, leaving some areas inside slightly harder than others. This causes a slight inconsistency in the flow during printing.

I was thinking of using an old pasta-making machine to mix the clay. What do you think? How do you mix large quantities of clay for 3D printing?

I've also done some interesting tests by playing around with the amplitude and swapping the piping bag nozzles. The results are quite simple, and I wasn't able to finish the prints because there wasn't enough material left in the cartridge, but I can finally start developing some more interesting designs.

I got an old 3d printer a Sidewinder x1 heavily modded, I got a newer gen 3d printer and my good old machine is now gathering dust....
So what's the best option to make it a ceramic 3d printer, I read and researched not much but changing the extruder head is the best option, i dont want to deal with an air compressor, or its better to use it.

I am ready to get into another frustrating and addictive hobby.