I have been searching around on google and not found any answers to this dilemma. I am using a Prusa I3 printer with PLA, trying to print horseshoes for the company I work for. They are for model horses, so quality is fairly important. I seem to have gotten all the settings dialed in just the way I want them and for the most part, the prints come out fine. There is however one annoying thing that keeps happening. When the filament is going around the curve of the top of the horseshoe on layers beyond the first, the filament does not follow the curves of the first layer. But its not every time. It seems like it is just the 2nd or 3rd Layers that are doing it. I have adjusted the flow rate, the speed, the layer height, temperature, and nothing seems to get rid of this irksome issues. I can of course provide more in depth details, and am including a pic of what i am getting. Any Ideas?
It could very well be that your print speed is too high (starting from the 2nd layer) for the motors to keep up comfortably. Try reducing the print speed to perhaps 75-80% of what you are using to see if it addresses the issue. You should also check you model to make sure there are errors in the STL. Sometimes such mesh errors can cause funny things to happen. Do you see the irregularities in the print preview at all?