Under extrusion with UM3

[vsardenberg 0]

I am runing into constant under extrusion with my UM3.

The nozzle is cleaned and I tried a new Print Core.

Everything so far with no noticeable changes.

The first layer is just a mess with way to little material being extruded. The extruder itself appears to be working properly. It is grinding away the material.

The nozzle definetly gets hot but maybe not hot enough? The macheine says it reaches the desired printing tempretature of 215°C.

I am runing an identical machine next to it with the exact same settings and it is working properly.

It might be an issue with the print head board, because everything else (the Print Core, Extruder, Bowden Tube, Filament and Settings) is as far as I can tell fine.

I took apart the head of the printer but could not find any visible issues.

 

Currently my next step would be to buy a new print head board.

Are there any steps you can recommend, that I could try before?

[Smithy 1,144]

I don't think it is the board.

Have you changed the Bowden tube? 

Have you tried to print with print core 2, do you get the same issues there? There you have another feeder and Bowden.

 

Try to remove the Bowden tube from the feeder, heatup the nozzle to 215C and try to extrude filament manually by hand. Just to see if you feed some resistance or something else. You can also try to load the filament in that way, to see if there is resistance in the Bowden tube.

 

 

[vsardenberg 0]

On 9/16/2020 at 5:19 PM, Smithy said:

I don't think it is the board.

Have you changed the Bowden tube? 

Have you tried to print with print core 2, do you get the same issues there? There you have another feeder and Bowden.

 

Try to remove the Bowden tube from the feeder, heatup the nozzle to 215C and try to extrude filament manually by hand. Just to see if you feed some resistance or something else. You can also try to load the filament in that way, to see if there is resistance in the Bowden tube.

 

 

Hi Smithy,

 

We already replaced the bowden tube. 

When you push the filament manually, it goes through easily.

[Smithy 1,144]

Ok, but try also to print with the right core, just to see if there is a difference.

 

And one more idea, do you use a default profile in Cura? If not try it with a default profile again.

[vsardenberg 0]

I already changed the princore, the bowden tube, cleaned the material feeder servo box. It printed super well a 3 days print. Yesterday, when I started a new print, the same problem occur: it starts printing well and then underextrude:

 

[vsardenberg 0]

[Smithy 1,144]

What about the middle/front fan, is is clean and working when the print core heats up?

[vsardenberg 0]

hello!

 

The fans are working. If I flip printcores and print PVA in printcore 1 and PLA in printcore 2, it seems to be fine. Any guesses? 

[JohnInOttawa 104]

Just so I have this correct, when you swap your Printcore from position 1 to position 2, you are able to print PLA fine in position 2?

 

If this is correct, then I would look upstream of the printcore.  Bowden tube obstruction or disconituity (maybe not fully seated at one end), or a feeder that is worn or needs cleaning/tensioning.

 

J