Why is there overhang at the buildplate

[Tarkahn 2]

 

I've included picture.  After I installed the newest version of Cura (4.4.1)  I now get an overhang at the bottom layer where it should be flat with the build-plate.  This has never been an issue until I just today installed the newest version.  I assumed the print would automatically touch the buildplate - Is there a trick to getting this back the way it used to be?  I also tried an earlier version of cura and got the same problem.  The first few layers are printing support material - it looks terrible.  You can also see from the second image that I have "Automatically drop models to the build plate" checked.

 

You can see from the image that I'm testing this out by printing some flat plates - I've searched the forums but have not been able to find an answer to this specific problem.  None of the posts related to this had any resolution that applied to my specific problem.

 

I'm printing with an Ultimaker 2

 

Thanks for any help - I appreciate it very much!

Edited January 18, 2020 by Tarkahn
add image showing proper settings

[Framar 38]

It's the same behavior in 3.6. The bottom flat surfaces are shown in red. If you look at the first layer, does Cura print support or bottom layer??? 

[Tarkahn 2]

Thx for the response Framar.  I've included a picture of Layer one and only part (just over half) of layer two.  Blue number one represents the very first layer - the fans were not running.  Yellow number two represents Layer two which began on the left side on a crosshatch pattern and that is when the fans started to spin.  I aborted so I could take this image of first and partial second layer.  the first layers are terrible and so you can see why I'm assuming there is some sort of over hang issue at the buildplate. 

 

I'm including machine settings also just in case there is some issue there:  I'm also printing this with 1.75 mm plastic on .06mm Extra fine setting with 20% fill.

 

I'm also including image of the top of the print for reference so you can see all the layers above the first two are great . I have leveled the bed to be sure and turned off the option to generate support.  So if it's not support that is being printed at the buildplate - what is causing the poor printing of the first couple layers?

[Framar 38]

Tarkhahn, 

 

First thing I've noticed on your picture is the skirt. It's should be better looking... it's OK on the bottom left corner but not so good on the opposite corner. Since your part is not that large I don't think it is related to bed leveling but you can have a chek anyway. Maybe your nozzle is just too far away from the build plate on the first layer.It is important that you squish that layer. You can also increase flow volume on the fisrt layer. Mine is at 120%

 

I can confirm that your part is perfectly flat and touching the build plate in Cura; there is no overhang. If that would be the case the skirt would not have been around the part like we see on your picture but it would be  underneath. See screenshot below.

 

[Tarkahn 2]

I am currently playing around with line width and flow -also I'll reset the buildplate a little closer to the nozzle (more resistance against the paper) and see if that helps.  I also did a test of line width set to 200 and got a slightly better result though. a

 

I'll also change the brim to a skirt so it's a little clear about the continuity between the skirt and the actual model - I see your point about the model being perfectly flat on the buildplate I'm convinced that it IS on the buildplate and is not an overhang issue - I'll ignore the misleading red and assume cura knows what it's doing 🙂

 

After I make those changes I'll take images and repost - hopefully with settings that solve the problem. - Thx Framar!

[ahoeben 2,012]

The red "overhang" indicating overhang where the model touches the buildplate is just a visualisation artefact/oversight. It does not affect slicing.

[Tarkahn 2]

Thanks everyone!  Problem solved.  I'm now convinced it had nothing to do with cura settings.  It was a "hardware" problem.  I didn't have the Bowden Tube installed all the way into the hot end and the extrusion material was bowed through the nozzle and not entering the hot end in a proper way.  When I accidentally discovered this, I pushed it all the way in, re-fed the material and now it's working flawlessly at all original settings.

 

Still, I'll be sure to play around with initial layer width and flow settings just because it's interesting to see what effect those have.

 

I'm very thankful for the comments and help - the lesson learned is that making sure all the basics are covered before blaming the software.  Things like, is my printer plugged in?  Is the bed level etc etc

 

Thx!