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3D Preview Issues

rkdartrkdart
in Repetier-Server
Hello,
  I've noticed that pretty much every G-code I upload generates a large blob (roughly the shape of the surrounding object) for the first 10mm or so of the model.  This was fine in previous versions of the software but happens now (Repetier Server Pro 1.0.1) for everything I upload, even old g-code that rendered correctly before.  Is there a setting that can fix this, or any hope for a fix?  It makes some of my models almost unrecognizable, though they print perfectly fine still.

Thanks!

Comments

  • RepetierRepetier
    Might already be fixed. Please check if 1.0.3 still suffers that problem. If so please provide an example. There was a problem when you extruded at e.g. 10mm height after homing a 10mm extrusion height was assumed since that is the layer height difference. Guess that is what you are seeing.
  • rkdartrkdart
    Hello, I tried this on 1.0.3 and it still has the problem.  Not sure how to attach an example file, but could provide one if somebody can explain how that should be done.  Problem does seem to be that the G-code is determined to have an initial layer height of the top of the blob, as seen on the right when I go to the preview.  I've tried adding an earlier "G1 Z0.0 F225" and similar, but it still determines 15mm is my starting layer height (this is from some automatically added code that tells it to raise up a bit and extrude to prime the extruder).  Is there some G-code I can add to get it to think that the initial height is actually 0.0 instead, which I think would fix this?
  • RepetierRepetier
    See PM
  • rkdartrkdart
    edited March 2021
    Here is a small example file that shows this:


    and the result:


    When viewing in Repetier-Server 1.0.3, it says the first layer is 15mm, and the second is 0.3mm; seems like it should be looking for the lowest layer height and using that to begin, rather than the first layer height (though I'm still not sure what the logic is for determining what the first layer is -- if I knew that I could work around it, most likely).  Thanks!
  • RepetierRepetier
    Ok it is quite clear. This is the code:
    G28 Z0 ;move Z to min endstops
    G1 Z15.0 F225 ;move the platform down 15mm
    G92 E0 ;zero the extruded length
    G1 F140 E30 ;extrude 3mm of feed stock
    G1 X20 Y0 F140 E30

    After G28 z is 0, then you move to z=15 so printing at that height means layer height 15mm.
    G1 X20 Y0 F140 E30
    then moves x 20 mm while extruding 30mm filament. That is what gets computed as the thick extrusion.

    That is also much too high for extrusion so you will most likely drag it behind you. My suggestion also to make it render better is to replace it with this gcode:

    ;@nosize
    G28 Z0 ;move Z to min endstops
    G1 Z0.3 F225 ;move the platform down 15mm
    G92 E0 ;zero the extruded length
    G1 X80 Y0 F140 E30

    This should at some point extrude enough to stick to bed so when you leave the line for printing it will stick there. The @nosize / @size is so that server does not sue that line for view calculations so it zooms on the print object better.
  • rkdartrkdart
    Thank you very much, that seems to work well for the rendering and I will experiment with the initial amount/height to extrude.
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