Hi I have just finished building my prusa i3 from Greg colbourn. I am running through calibrations and I have been trying to test the extuder. I am using pronterface. Right I loaded the filement(3mm green ABS) locked it in with the screw spring things (not to tight), I heated the head up to 230c and the clicked extrude 60mm. I got about 40mm and then it dropped to a slither.and tried again to produce another 60mm and it doesn't want to come out. Everything is fine with the stepper, hobbed bolt all going right way and not binding, I tried pushing on the filliment manually and it help a little bit still a very slow supply. I then tried ramping up the temp in increments all the way to 260 with no luck. I then got my infared thermometer out and pointed it at the head and it said it was at around 190c, now this was when I was near 250c on the comp. Which do I trust.