This is a very simple spool holder which requires no supports and no infill if you use enough shells. I personally used 3 shells and 0.2mm layer height. I used 60mm/s for the print with the outside shell being at 30mm/s and it took roughly 1 hour and 20 - 30 mins (I printed 2 and so my bed was already warm giving different finished times).

I made this after trying to print another one I found online and it required supports which just didn't want to play ball.

I designed this model so it doesn't require supports and there is no harsh overhangs which could also cause issues while printing. I was able to add a large flat bottom to the part which greatly increases the adhesion to the bed so we are not worrying about this part coming off the build plate half way through the print. I have tried to remove all sharp corners from this model either with a radius or a small chamfer of 0.5mm.