Florian Maurer developed a DIY sensor to register nozzle clogging and print failure.
It is easy to make since it consists of a rotary encoder, some thin foam tape, and some 3D printed parts with Arduino used to listen to the grey code from the rotary encoder and send the data over serial to a Python script.
When the filament slows down or stops due to a nozzle clog, the Python script plays a notification sound to let you know that you should check your nozzle and that your print might fail.
Project homepage with more details and Python code needed:
http://www.cuddleburrito.com/blog/2015/6/11/preventing-failed-prints-with-filament-feed-encoder-and-arduino
It is easy to make since it consists of a rotary encoder, some thin foam tape, and some 3D printed parts with Arduino used to listen to the grey code from the rotary encoder and send the data over serial to a Python script.
When the filament slows down or stops due to a nozzle clog, the Python script plays a notification sound to let you know that you should check your nozzle and that your print might fail.
Project homepage with more details and Python code needed:
http://www.cuddleburrito.com/blog/2015/6/11/preventing-failed-prints-with-filament-feed-encoder-and-arduino