phrozen5100

The fan I'm referring to is the main fan in the print head located in the front. Per Ulrich's link, this procedure helped to solve the issue.

Update: I figured out one of the problems. The inconsistency was a result of the fan being occasionally jammed by some PVA strands from the previous owner. This was causing heat soak in the hot end, essentially reducing down and - in one case - actually fusing the filament to the tubing. Clearing the fan up completely and cleaning up the feeders has resulted in good prints. Hopefully this helps somebody, as I never would've expected to see that. Now onto other issues...

Update: I ended up cleaning the feeders again, swapping Bowden tubes, and refeeding per the instructions I found on an earlier post. After 3 mostly successful prints, I'm experiencing consistent underextrusion again. I'm convinced this must be some sort of software/firmware related issue, as nothing has changed mechanically since the successful prints. Failure mode is the same on both nozzles, going from normal flow during the successful prints to no flow at all on subsequent prints. I changed models and resliced using the same settings as before. Filament is new Ultimaker filament and filament guide is attached. Thoughts?

Hi all, new Ultimaker owner here coming from a Makergear M2 (still owned) for personal use only. I purchased this unit lightly used from a business owner who only used it primarily with the AA 0.8 nozzle for printing shipping brackets. I swapped both cores with AA 0.4, running Tough PLA and regular PLA in each. I have updated to the latest (stable) firmware 6.5.2. I have spent more time than I care to share tinkering with this machine with more frustration than luck. My main issue is as follows: Very inconsistent underextrusion - even using manual extrusion. Sometimes the unit will extrude, and sometimes it does nothing at all and simply grinds the filament. I've tried tension settings in the middle as well as about ±25% either way as well. This issue happens with both AA 0.4 cores in both positions of the print head, and I haven't been able to identify any rhyme or reason why it's behaving like this. The pattern that typically occurs is that the initial lines printed start off thicker and eventually the printer stops extruding. I have opened and cleaned out both feeders, and they seem plenty strong tugging on them during feeds. I am able to manually extrude cleaning filament through the heated nozzles without issue. I have done several cleaning cycles of both 0.4 AA cores without change. During manual extrusion, if I retract the filament significantly and send it back through the extruder, it tends to extrude for a bit before stopping. Swapping one of the heads with the AA 0.8 yielded one good print, with that nozzle occasionally printing without issue (until it just stops feeding). With retraction turned off and flow up, the AA0.4 worked for one print, but the lack of retraction ruined the print. Turning up flow to 110% and turning off retraction seems to yield successful flow, but the part quality is horrible without retraction. At 100% flow and retraction disabled, underextrusion is also present. I have also swapped out different filaments with the same results. 0.8 nozzle side has occasionally errored with the click of doom in the feeder and subsequent "out of material" error. I can't seem to replicate these print jobs, further lending to the frustration. I cleaned the original Bowden tube, but this did not seem to resolve the issue. I also swapped in a new Bowden tube, but the ID was larger, and underextrusion was still present - but improved - with excess buildup presumably due to compromised ability to retract under control. I've ordered new bowden collets and clips as well as E3D replacement PTFE Bowden. The original Bowden tubes seem to be in good condition, as best as I can tell. I've already canvassed the forums for underextrusion issues, and my main thought now is the Bowden tubing or one of the connectors is inducing just enough excess drag to keep it from feeding properly...with the 4mm ID Bowden allowing too little control for proper extrusion/retraction but little enough resistance to allow for consistently underextruded lines. I'm shocked that for the popularity and reputation of this machine that it thus far seems to lack in robustness and consistency, whereas my Makergear seems near bulletproof. Any other suggestions on things I can try before chucking this unit over my balcony?