Missing exterior between print preview and actual print

Something I have noticed with the latest 2.0.1 is that when I attempt to print objects they slice beautifully, but when they print in both the manual control and on the printer output there is missing outer layers as can be seen in these screenshots.  For a couple prints I assumed that it was an issue with my hardware, or perhaps my settings, then I noticed the details missing between the slice and the print.  It has persisted through multiple different models and print settings, any thoughts on what may be causing it and how to rectify it? Thanks.

Print Preview

Printer Output


  • So when you print the preview your print is correct but the drawn rendering is what you show?
    Can you provide the gcode for this so I know it must get the error. You never know what trigger sit but looks like an error on our side and as soon as I can reproduce it I can fix it. You can use dropbox or pastebin.com or just send me an email with gcode.
  • Thanks for your reply, attached is the GCode from the print.   When looking at the file after slicing, the exterior of the model appears complete, once the print begins and youre monitoring the printer output it appears to skip outer layers in both the software and the printed model reflects those omissions.  It does it on multiple models (the one I have submitted I have been usiing to try to test and diagnose the issue as it is a small model that is easy to observe the issue on.  I can also provide all of my config information, however the issue seems to persist even with adjusting settings such as Esteps/mm, extrusion multiplier, etc

    below is a link to the gcode, my config settings, and some additional screenshots
  • edited May 2017
    please let me know if there is any issue with the linked files and I will try to reorganize them, also this is defiantly a issue that has occurred when i upgraded to 2.0.1, I was not seeing this on earlier prints
  • I'm really wondering that it affects the print. AT first everything was fine for me. But setting variables for print visualization from "Layer Height" to "Filament Diameter" makes it create these visual glitches, but only in print visualization.  It is also a bit random and it seems it happens somehow when new moves get compressed to the main content that it adds a wrong extrusion. Needs further investigations on our side.
  • It does affect the print, here is a picture of items made with this visualization (on the left)

    https://www.dropbox.com/s/2r9an7bnihm4kqb/2017-05-19 08.30.12.jpg?dl=0

    you can clearly see the missing sections of the exterior, these correspond exactly with the ones that show up on the "manual control" tab's visualization during a print.  You can see it happens regardless of the material and the model. On the right are two older prints that exhibit none of these defects.  Below is another print of the same blue material that was done even further back (filament was stored in a dry box between prints) that has absolutely none of these gaps in its surface (for perspective these are larger than a soda can).

    https://www.dropbox.com/s/tj0ig7wp22086uf/2017-04-05 14.19.24.jpg?dl=0
  • I will test. For now I can only see some of these artefacts if I set width calculation to derived from diameter.

    Can you try if setting it to layer height would help the print as well as the preview. I will test at the weekend and hope I see something explaining it.
  • printed with your suggestion of altering the layer height, while it has removed it in the preview, the print came out with almost the exact same defects as before, currently printing a 3rd with a smaller Z layer height.  Again I would have chocked this all up to some mechanical fault with my machine if not for the fact that when observing the Repetier 3D View I could see the flaws being described by the software as they appeared in the print.

  • i have updated my shared folder to include additional screenshots of my display, the surface flaws occur with either setting, and are only visible in the 3D View when I have selected "filament diameter".  Decreasing the Layer Height in my latest test only served to decrease the size of the surface flaws, not prevent them or reduce their quantity.  Thank again you for your assistance in this, I really do value Repetier-Host and prefer it over the alternatives.
  • I could trace it down to the rendering function. So the appearance of the rings in the physical print is completely independent of the graphic error you see. It is just a coincidence you have here. Strangely if I slice a simple small cylinder with my settings I do not see the error while slicing with your config.ini does show it. But maybe it is just from the order or extruding so that I have the error on the inside which you have on the outside. Maybe I get more insight when I find the line causing the error, but it is hard to find.
  • I think i have found a mechanical source of the issue that somehow across at the same time as my code upgrade to 2.0.1 involving somehow my X-axis to no longer be horizontal, and the gap between the stepper motor and the X rail on one side to be vastly different than the other by at least 1.5 cm, I rectified the disparity and the test cube I printed last night seems free off the gaps that were plaguing me before.  The print monitor still does occasionally produce those errors in the filament traces though, so I am glad I could bring that to your attention and do greatly appreciate your support in this manner.  In a couple days I should b e able to do some more prints on my machine to further verify that this was the culprit all along.
  • Just as a not for the graphic problem. When compuing from extrusion it had a ugly aspect if using low extrusions as here roundign errors can become dominant and produce wrong thickness. This is what happened for you plus that it only updates thickness on extrusions > 0.5mm which did not happen in your sepcial case with tiny segments.
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