My little “saw tooth” problem.



  • Here’s a photo of what’s happening. I was hypothesizing that it was a z-step issue after trying every suggestion thrown my way. It seems to “reset” every 4 or 5 layers, then compound over the next few layers again. It’s only in the corners. The sides are perfect!



  • 0_1548330605317_2019-01-24 06.43.03.jpg



  • EDIT: it is only in the corners - Then I might suspect it is the retraction - Try to change seam position to "Aligned" and see if it only occurs on the corner where the layer starts / stops



  • Simplify3d?



  • yes, simplify 3d



  • it doesnt happen to match the pitch of your z axis leadscrew does it?



  • I do see that the saw tooth (Bulge) is happening where the perimeter stops. when it finishes the outside pass, it leaves a little blob. The reason it's in all 4 corners, is because simplify 3d was staggering the seams. they all end up in the same place if I align the seams.

    I'm reading and reading up on retraction, but I am not finding anything that really pertains to the duet. Is retraction in the slicer, or in the firmware?

    I see no retraction settings in my config.G

    is anyone familiar with A Duet / BMG / E3Dv6 / Simplify 3d setup that could explain where I might look to adjust retraction?

    Thanks!



  • Retraction is done in the slicer - For S3D, you can see it here:
    https://3dprinterchat.com/wp-content/uploads/2017/04/FFF-Settings-600x365.jpg



  • @martin1454 Unless they're using firmware retraction (G10/G11), then it is a M207 setting in config.g.



  • @stephen6309 said in My little “saw tooth” problem.:

    @martin1454 Unless they're using firmware retraction (G10/G11), then it is a M207 setting in config.g.

    Well, S3D does not support it "natively" - You can do it, but it is a bit tricky.



  • @steve-lynch said in My little “saw tooth” problem.:

    I do see that the saw tooth (Bulge) is happening where the perimeter stops. when it finishes the outside pass, it leaves a little blob. The reason it's in all 4 corners, is because simplify 3d was staggering the seams. they all end up in the same place if I align the seams.

    I'm reading and reading up on retraction, but I am not finding anything that really pertains to the duet. Is retraction in the slicer, or in the firmware?

    I see no retraction settings in my config.G

    is anyone familiar with A Duet / BMG / E3Dv6 / Simplify 3d setup that could explain where I might look to adjust retraction?

    Thanks!

    I have the same combo on my printer, direct drive. My retraction settings in s3d are 1.1mm at 50mm per sec 3mm wipe and no coast. Works well



  • @martin1454 S3D does support firmware retraction natively although it uses different Codes for it but RRF was altered to accept them some time ago.

    Doug

    0_1548411484206_7e24e68f-2b19-4489-8ce9-6b93dd164040-image.png

    it is the include M101/M102/M103 commands setting



  • @dougal1957 said in My little “saw tooth” problem.:

    @martin1454 S3D does support firmware retraction natively although it uses different Codes for it but RRF was altered to accept them some time ago.

    Doug

    it is the include M101/M102/M103 commands setting

    Also remember to dissable "Retraction" on the extruder tab


  • administrators

    The M101/102/103 commands don't do a perfect job. I forget the details, but there is some situation in which the commands are not correct for controlling firmware retraction.



  • @dc42 Ah OK David I wasn't aware of that as I don't use S3D anymore so won't have run into that issue



  • @DC42 I have all but eliminated my problem from what I can see. However, I'm concerned about how I did it. I have tried every combination of speed, accel, Jerk, extrusion multiplier, retraction, etc.... What seemt to have killed the problem was Pressure advance.

    Here's My concern though. I have pressure advance set to 0.14 that seems an awful way off from .05. Is this a problem? My prints look amazing, I have no artifacts, no under extrusion, and almost no blobbing in the corners now.. I can't feel them, but if I hold it in the light, I can see a slight change in the reflected light. (if you know what I mean) Non squares are looking perfect! I printed a carbon fiber bust of a naked woman, and it looks super for the settings I used (a little better quality than fast in Simplify 3d)

    so, Am I covering up a bigger problem, or is this what Pressure advance is there for?

    Thanks!

    Steve


  • Moderator

    @steve-lynch I think that if your prints are looking good you must be doing something right.


  • administrators

    If pressure advance of 0.14 works well for you, stick with it!

    The required pressure advance depends mainly on the length of the Bowden tube between extruder and hot end (longer = more PA), and on how sloppy the fit of the filament in the Bowden tube is (more sloppy = more PA). But it also depends on other factors such as motor current and gearing (low motor current needs more pressure advance, so does low extruder steps/mm). The suggestion of 0.05 sec pressure advance for non-Bowden extruders is just a starting point.


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