@arapp: You may try if you can push the filament through the heated hotend manually. If you feel a significant resistance, your problem is with the hotend. If you don't, it's likely with the feeder. Don't forget to test with and without the Bowden tube. If the filament is changed with the 'change filament' option, a very fine string is deposited in the Bowden tube. This string can make your filament being stuck in the Bowden.
Are you printing PLA?
I just replaced my nozzle, teflon spacer and cold end on my UM2 which temporarily solved the underextrusion issue. After a few prints, however, the problem came back. It seems that switching between ABS and PLA is a problem for these printers.
I'm still not sure it is a 100% solution but I put some vegetable oil on my PLA filament and have run a couple of very good prints in PLA after doing that. It seems that vegetable oil is a known cure for PLA's stickiness to just about everything.
Link to post
Share on other sites