My first print was normal, filament was sticking to plate and everything works fine. But then i wanted to print fanduct for my printer. But it started to not sticking and collecting filaments in tip of nozzle. Here is my pictures and videos. Please Help

http://youtu.be/fkADjzBpyFo

https://youtu.be/c4rjEHTD9M4

Looks like nozzle is not close enough to bed. Check z offset or z limit (if you have one).