squeens

I want to print a cylinder empty inside, with outer diameter 5.5mm and inner 4.5. I have an Ultimaker 2+, using 0.4 nozzles, so I choose a line width to 0.35, infill density 100%. For now, the better speed is 15 but however there are always holes in the wall of the cylinder, what can I modify on the Cura setting? I ve als tried making a support