Filament get stuck in the top of the printhead

Vertex 3D Printer Vertex - Issues while printing
21

Dear Zorro_X,

I had this understanding some times before too. But when I was working on the pressure advance implementation, I had a very impressive experience. I have set up a small test structure to measure the impact of the pressure delay and the effectiveness of the pressure advance mechanism (the octagone I describe in my blog http://ddd.k8400.hoehnemann.net/index.html). I asked a college to to a test print with his 3D printer, which has the extrusion feeder directly on top of the hotend. I was very surprised that the pressure delay was visible in the same severity like for my K8400.

So my conclusion was:

except you are using elastic filaments, there is a negligible impact on the pressure delay coming from the bowden.

The elastic part which is responsible for the pressure effects is in the hotend at the junction between cold entrance of the hot end and the liquid phase of the filament. http://ddd.k8400.hoehnemann.net/Theorie.html

22

Thankyou hoh61 for your experience sharing, I didn’t expect that answer so I’m impressed as well as deceived because it means there is no solution against that “pressure problem” if I understand well… :frowning:

23

Don’t get me wrong,

maybe there is not a solution, but at least an improvement by using the pressure advance approach. This is implemented in my firmware mod, which is available on my side, too. Actually it is implemented in the firmware version for two nozzles, but by setting the configuration parameter to one nozzle it still should word (not proofed yet).

Please feel free to test it.