I have an ultimaker 2 that I've been using for over two and a half years now. I am a teacher at a junior high and I typically use it to just print out random things for students for rewards in class. They find some cool stl files on thingaverse and I print out a copy of it for them. This year I have been having quite a bit of trouble with it. Once the print gets past the beginning stage, everything seems to work fine. But most of the time the material gets hung up in the feeder and doesn't end up coming out the nozzle. I am using PLA material. The print will start, and some material will get put down, but then after one or two passes, the material stops flowing through. At first I thought the nozzle was constantly getting clogged, but then when I tried to "change the material," I noticed there were points were the feeder had worn through the material trying to feed it through the nozzle, but it wasn't moving. When I pulled the material out, cut off the offending indented part, and put it back in, the print would work just fine. The problem is I have to do this with nearly EVERY print. Do I increase the material flow? Increase the temperature? Is the PLA material being nearly three years affecting its performance? Thanks for any suggestions.