i didnt read red's link but your part needs more cooling time. i always try to print things like this along with other things so the hot end doesnt stay in one place too long and gives a longer cooling time. if you dont have anything else then try printing a 2-3 outlind skirt the same # of layers as you model. it will do one later on the model then go around and print the skirt allowing the fan more time to cool the soft plastic.