Over the last week, I have been having new challenges with the 3d Printer, as I have been trying to print rather large parts. Initially, I could not get the filament to adhere, or it would be splotchy and rough at different sections. As usual, a lot of this was a matter of constantly tuning the finicky machine. Adherence was due to mainly leveling the bed (again), and in my case turning down the temperature of the nozzle. With the basic Hatchbox Grey I typically use, 205 degrees was working well. But with my new roll of Gizmodorks Copper PLA, I eventually had to turn the nozzle down to 180. Then I had a lot of warping in the part, so I increased the bed eventually to 60 degrees.
Once all those were in place, the prints starting working reliably again. Until a couple of nights ago, when the print jammed about halfway thru. At that point, everything looked good, but no filament was extruded. As normal, I unloaded and reloaded, and for a brief time, filament would come out, and then the flow would slow and stop. Each time I tried to print, only a little would extrude, and it quickly snagged and pulled itself from the bed. A couple of frustrated days and numerous failed starts later, and I finally determined it was not temperature or balance, but maybe the nozzle had just failed. So out came the tools and I set about disassembling the nozzle – which actually turned out much easier than I expected.
Here is where the mystery comes in – and perhaps someone can offer an explanation. When I removed the nozzle and the PETG tubing, I found an extra piece. A small black plastic tip, right at the end of the PETG tube, which would be right at the end of the nozzle when assembled. This plastic piece was jammed solid with filament, and seemed to be the issue. However, after digging thru google, I can find no mention or purpose for this piece – all details always seem to indicate the PETG tube goes to the nozzle with nothing in between. Would anyone have any idea what this piece is, and if it is important?
In my case, I set it aside, assuming it was the cause of the fault, and re-assembled the heating block. After re-leveling again, I re-loaded the filament, and now it extruded cleanly, straight, and steady. I ran a test print, tweaked the bed alignment slightly, and then ran a large print. And now the printer is working admirably again – the first large layer was nearly perfect. I still have some issues with ghosting in some corners, and there is a small void in one small section (likely due to an infill issue on the model), but otherwise it is back to operational status. And the print ended up fully successful after 8 hours, with no jams.
But still no idea what that small black piece is, or where it came from. It is too uniform in shape to be a clog of PLA, but doesn’t seem to serve any purpose.
