I print everything in abs as most of what i do is rapid prototyping and i need more rigidity.
The hose used has a .170 id and .25 od. Both those measurements are critical as there is a nipple inside of the nozzle the hose goes over (shown in one of the pics). The .25 is the obviously what the hose goes through. I purchased the hose from home depot by the brass fitting section.
The lower the resolution the smoother it will move but i just sanded the balls with 400 sandpaper before putting them together. There is a hose in the middle so if you move it too much the pressure will pop them apart. No biggie just snap them back together. Need it longer you can just add another section and pull the hose through.
The only place you need supports is on the nipple in the middle of the nozzle.
Bolt is a 3mm but the threads are not printed. Either tap or just run the screw into the plastic and it will make the threads.