UM2 firmware v15 under extrusion issue ?

[boris 0]

Hi there,

 

I have been doing good quality prints on my Ultimaker 2 from the beginning, (I have it since about four months).

But since a while I started to have under extrusion on most of my print and that was append with any filaments I have (all my filaments are from from ultimaker)

Also I was using the same settings of before, when my print was good.

 

I tried everything I can to fix it, changing the temperature of the nozzle, the bed and many settings.

I made a lot of atomic method to clean the nozzle, I dismounted the nozzle to checked the teflon.

 

I also tried the alternative feeder from Robert and printed a bowden hook to try to improve the flow.

https://www.youmagine.com/designs/yet-another-ultimaker-2-feeder

https://www.youmagine.com/designs/bowden-hook

 

In the same idea I removed the spool and unwound the filament to reduce the tension, after I read that here :

http://ultimaker2prints.blogspot.ch/2014/11/dont-over-tighten-material-feeder.html

 

All of theses things wasn’t really a success and the under extrusion was stil there !

I was wondering what can be changed on my printer, and after one week of testing I remember I did a firmware update (15.02.1)

 

Then I Downgraded to the firmware version 14.12.1 and magical! Since I did the downgrade I did not have anymore obvious under extrusion.

Is someone know or/and have the same issue ?

 

Cheers,

Boris.

 

 

[Anders Olsson 136]

For the 99% flow bug, I reported that one five months ago but apparently it has not been fixed yet.

http://umforum.ultimaker.com/index.php?/topic/7764-underextrusion-when-flow-is-set-below-100/?p=72702

https://github.com/Ultimaker/Ultimaker2Marlin/issues/42

I did another test to check if it still is there, and yes it is:

I believe this bug can potentially cause a lot of unnecessary support-tickets, so it would be good if Ultimaker would fix it at some point.

Regarding under extrusion and the V15 of the firmware, this in an interesting one.

Lately, I also observed slight underextrusion which appears be a software issue rather than anything mechanical.

I will do some more printing and roll back to an older version to test this on my machine too.