Diagnosing issues with a print

[NonSequor 1]

I have a print job that so far has given me two successes and about eight incomplete prints that have run into issues at the same spot (towards the end of the print).

It looks like in the part of the print where there are issues, there's a roof and it looks like for the last part of it, the head is tending to dig into the still soft previous layers rather than laying down anything new and I think the back pressure is tending to cause filament grinding. I'm guessing that sometimes the print job makes it through the tough spot without grinding down the filament and manages to start depositing layers again.

I'm printing with black ColorFabb PLA/PHA. I've tried recalibrating the build platform with different levels of resistance when testing the distance with a piece of paper. I'm printing with a layer height of 0.2mm and a shell thickness of 0.8mm.

The print job has text at the top and I modified the original model in OpenSCAD to remove the original text and add new text. One thing I'm wondering is if my modifications have created any issues with the STL since I had issues with some of the approaches I had tried to doing this and even with the one I finally settled on, there are some oddities with how the model is displaying in OpenSCAD.

This is driving me nuts given that I have two good looking prints, but at this point I'm wasting too much filament and time trying the same thing repeatedly.

[stu_le_brew 42]

have you tried looking at each layer in Cura using the layer view ?

[NonSequor 1]

have you tried looking at each layer in Cura using the layer view ?

 

Yes, but I'm not sure what I'm looking for.

[neotko 1,417]

 

have you tried looking at each layer in Cura using the layer view ?

 

Yes, but I'm not sure what I'm looking for.

 

You might need to start by the basics. Read this very very nice guide to locate the kind of problem that you have.

http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide

If the problem it's on the stl, repair it first:

https://netfabb.azurewebsites.net

[NonSequor 1]

 

 

have you tried looking at each layer in Cura using the layer view ?

 

Yes, but I'm not sure what I'm looking for.

 

You might need to start by the basics. Read this very very nice guide to locate the kind of problem that you have.

http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide

If the problem it's on the stl, repair it first:

https://netfabb.azurewebsites.net

 

I've been referring to the troubleshooting guide and I've been focusing on the "grinding filament" section. I've tried adjusting the screw on the feeder, but that hasn't helped so far.

I tried the STL repair, and I'm not sure what's going on, but I can't print the gcode I'm generating from the repaired STL. It doesn't show up on the list of available print jobs, and I've tried generating it several times now.

[neotko 1,417]

For the stl. Just a hunch. Try to rename the gcode to something simple.

Forbthe grinding. Change the minimum retraction so it retracts less. Maybe it's a very demanding print?

[Labern 775]

in cura look at you model in X-ray mode to see if any errors come up in red or single face that can show black.

If its all purple and white then its OK.

You need to learn how to use layer view as this should be done before printing every model.

- Red = outer wall lines

- Green = inner wall lines

- Yellow = infill lines

- Cyan = support/skirt

- Dark blue = moves (thin lines)

[Labern 775]

It also helps to show pictures of you failed print and model.

[NonSequor 1]

It also helps to show pictures of you failed print and model.

 

Here's a successful print on the left with the failed one on the right.

Here's the model:

Going through the layers, the only things I can see that don't look quite right is that the red walls for the text start in the middle of the solid layers for the roof on the main part of the model and in the layers below where they start and it also looks like there is a ghosted copy of the text, although it's not clear if this is a vacancy in the layer. Or is that last part just an overlay of the 3d model on top of the layer view?

[danilius 118]

If you upload the STL file, we can all have a look at it and that way we don't have to guess too much

[stu_le_brew 42]

just had a thought - are these items printed on different places on the print bed, I would assume you are printing several at once if so I wonder if the stainless steel rods need oiling ?

its worth trying moving the print head manually to feel for any roughness especially in the area where poor prints are done

Edited November 9, 2015 by Guest

[NonSequor 1]

If you upload the STL file, we can all have a look at it and that way we don't have to guess too much

 

Well, I was hoping I had enough leads to get some kind of differential diagnosis going and try to narrow down the number of things I'm investigating.

Is there a way to upload an STL here without finding some place to host it?

[NonSequor 1]

just had a thought - are these items printed on different places on the print bed, I would assume you are printing several at once if so I wonder if the stainless steel rods need oiling ?

its worth trying moving the print head manually to feel for any roughness especially in the area where poor prints are done

 

No such luck, these have all been one at a time prints on the dead center.

[Labern 775]

 

If you upload the STL file, we can all have a look at it and that way we don't have to guess too much

 

Well, I was hoping I had enough leads to get some kind of differential diagnosis going and try to narrow down the number of things I'm investigating.

3

Is there a way to upload an STL here without finding some place to host it?

 

youmagine is the place people normally use around here.

So just to clarify, you issue is that it's not completing the print and the printer stops before the top lip and lettering is done?

[stu_le_brew 42]

I have just re-read your original post can you confirm the first two prints worked OK, since then have you

1. changed the design and it now does not print
   
2. it fails to print the same file
   

 

if its the first then its a problem with the software/design if its the second its a problem with the printer

question are you sure the two cooling fans are working correctly at the top part where the failure is ? I assume its the same filament

[neotko 1,417]

If it's what @Labern asks true (fail when doing top) might be related to retractions.  Post all your print settings. Check the little fan of your um2 if it's running (at 40-60C? on new um2 and when powered 'on' on 6-12month um2s).

Edited November 10, 2015 by Guest

[NonSequor 1]

So here's the STL:

https://www.youmagine.com/designs/truck-wheel

 

Print settings are Cura 15.09.81 defaults with the following adjustments:

general]

version = 1

name = Normal Quality (Customised)

[settings]

shell_thickness = 0.8

adhesion_type = brim

infill_sparse_density = 15

layer_height = 0.2

draft_shield_enabled = True

Specifically the issue is, it's tending to grind the filament and lose traction while the surface of the top lip is being laid and before the text, outer rim, and hub cap of the wheel are started. When the issue occurs, I don't think that the point where the filament breaks varies by much more than a layer or two.

The fans have been checked and I'm using stock materials settings for PLA.

I have had both successes and failures from the same file, with more failures than successes. I have printed other things successfully without tweaks while taking a break from trying to get this model to work. I'm wanting to think that this means that it's some kind of corner case between the model, the software, and the hardware where more than one thing is contributing adversely to the outcome.

[Labern 775]

Oh I should have asked what cura version you were working with earlier. Any CURA version number higher then 15.04.3 is BETA. The version you are using has lots of bugs and you may have found one.

So you can log this issue on the cura github.

But for reliable printing I would suggest using 15.04.3 unless you are happy beta testing.

[stu_le_brew 42]

To further test to see if you have solved the problem you could also try "cut off object bottom" set to 23mm so you only print the top problem part.

I have tried to download tour file but I could not download for some reason ?

If you look at the layers again in layer view and just change the layer height you will see it seems to spend more time printing the letters, so I suggest trying changes to layer height.