How to get rid of material "blob" at the end

[ndimensional 7]

Hi,

since some days I get an additional "blob" of material at the end of the print - see photos. So the print head is not immediately retracted at the end and some material is pressed out of the nozzle befor placing the print head at positon zero. No clue where it comes from and how to cure ....

It can bee seen on the blueish photo on the right, on the two others on the left. Object size 8x3 mm without brim.

Nd

[geert_2 557]

For such small items I always use this method (see pictures). If you make the dummy 1 layer higher than the real model, this method also prevents the blob from occuring on the models (they will be on the dummy, if any).

 

 

 

 

[ndimensional 7]

HI Geert 2,

thank you for this link and hint. But I don think that it adresses the real problem. It may be a good work around, but as you write - the blob is still there. The main problem I see is, that the material flow is stopped immediately and the print head is not immediately removed after end of print......the feeder is working still half a second after end and I never had this problem in the past. maybe Cura 3.2 is the root cause - or a change in the firmware with Cura 3.2... but maybe I am looking completely in the wrong direction.

[harbaum 3]

The german thread linked below is about the same problem. And there's also one in the french forum.

 

I also have the problem. It appeared with Cura 3.2 and also happens with Cura 3.2.1. Objects sliced with Cura 3.1 or earlier don't face the problem.

 

The odd thing is: There's no functional difference between the gcode causing the blob and gcode not causing it. The "good" version created by 3.1 just has a bunch of SETTING comments at the end. This should not make a difference. But it does.

 

 

[harbaum 3]

So far all reports seem to be from UM2+. On what machine do you face the issue?

[ndimensional 7]

Looks like its not a handling problem or produced by me  . Thank you for the reference to the other threads - yes, that's it. Well, it happened after a Firmware update with 3.2.0 - not sure what my last firmware version was.

And yes, same additional problem like the others: grinding so that the next print can not be started without some feeding fix.

My machine is an upgraded UM2 - to UM2+ with the upgrade kit from Ultimaker. Electronic board is one of the first series. So lets close this topic for now, will continue with my findings in the german thread. I will test now with combinationbs of Cura and firmware down to 2.5.0 - as far as I understood the problem came after this version.

 

Update February, 22nd:

Details in the German thread. Findings:

Need to add 4 lines of comment in the code via Cura (Preferences - Configure Cura - Printers - Machine Settings - End Gcode). Begins with ";", text itself can be chosen freely....

Edited February 22, 2018 by ndimensional