I am having a problem with my extruders while printing and only while printing. I can move my extruders via pronterface interface yet when I try and print nothing is happening or the wrong extruder is on. I am even unable to only slice a single extruder printer setting (all I have tried is one extruder at a time no matter if I told my slicer that my printer has 2 or 1 extruder) . Is there a startby revinval - Smoothie