Hey all, we have a strange problem with our Ultimaker.
It’s an Ultimaker 1, with the extruder and hotend upgrade. It was working ok for a long time, and recently started this strange problem. I’m not sure if it’s a hardware or software issue.
The first layers are always perfect, and then the print becomes spongy, as if extrusion rate is way too low, or the hotend is jammed. But if I restart the print, than once again the first layers are perfect.
Here is a picture. Left is 30% fill, middle is 80%, right is %100. Notice that the right one is perfect, and the rest have a few good layers and then it goes bad. It always starts good, and then goes bad, at about the same height.
I tried cleaning the nozzle, I tried uploading a fresh firmware, I tried downloading latest Cura and resetting everything. Same results.
I do not own a ultimaker, but I recently had similar Problems with my i3. It always seemed like the filament jammed and the ecxyruder had to be cleaned complete. At the end it turned out that my heatbreak was loose.
Have you an older version of Cura that always worked fine for you? (I save the best working not even the newest)
Also control feeder gear of the extruder and thermistor.
Is it possible to do a cold pull on the UltiMaker hot ends? If so, I’d recommend that, and clearing it out. Also, make sure your filament is high quality. Low quality stuff (to this day) occasionally has ball bearings in it. Occasionally once the back pressure is relieved, whatever is jamming the nozzle can kind of relax itself until more force is put behind it.
In addition to the cold pull, occasionally if I get a REALLY stubborn piece of debris, I’ll stick a firm metal wire up through the tip of the nozzle while at temp, and then lower it down to cold-pull temp and pull the wire through with the plastic. Usually this wire is pulled from a metal abrasive brush, so that it’s stiff and can push whatever is in the nozzle, out. I’ll clip it usually, once I have enough of it inside the nozzle. This is an advanced method only though, and I wouldn’t try it unless you’re willing to accept the risk that it might not work and it will require rebuilding your hot end.
Sounds like a partially blocked nozzle. Do a cold pull and check the tip is clear. Do consecutive cold pulls at progressively colder temps I’ve managed to pull as low as 145’C. You want the filament to come out as with as much debris as possible till its clean. When its clean look through amd you should see all the way through. What ive had happen is the very tip if the nozzle rubs to close on the bed and distorts a little narrowing so the tip actually ends up smaller, if that’s the case you can try to open the nozzle with a pin but will probably need to replace it.
I have never successfully cold-pulled with with ultimaker (I have with several other hotends). I tried many times. Something with the design prevents it? I’m not sure.
I’ve done cold-pull on other bowden printers before, and it worked. But even without the bowden tube, it still doesn’t work on the ultimaker. This could be a symptom of the problem? Maybe the PEEK insulator is deformed? I guess I have not choice but to take it all apart.
This looks similar to a problem I had in the past. Try reducing your retraction distance, my theory was that the molten filament was slowly being pulled up into the colder part off the hotend eventually leading to a jam.
