Stuttering on perimeters



  • Figured I'd come here after scowering the interwebs.

    I've had several problems with my Duet WiFi so far, but all of which ended up just being configuration errors of some sort because of having only ever used marlin in the past, and the odd ways of configuring a Duet is still weird to me lol.

    But, my current problem is thus:
    When printing straight line perimeters and occasionally circular perimeters, the printer just stops for a split second, then continues on. It leaves overextruded sections on almost every print because of it. I hadn't really noticed it before because generally I print larger things for a game shop, and it didn't really matter because the person buying it would be finishing it themselves. But I recently tried to print some things for personal use, and have constantly been getting slightly deformed prints because of it…

    At first I thought it was because of the start and stop location for each new layer, but this isn't the case… the printer starts at a corner each time. My only other examples are currently at the game shop (they were bowls for a local production plant to hold bolts), and they have a continuous arcing line throughout both sides, one from the seam, and the other where it just randomly pauses.

    I had thought maybe my accelerations have been causing it, as they were just stock, so I tried both doubling them, and halving them, and nothing worked...

    Its kind of odd and annoying when I watch the printer traveling down a straight line, and suddenly it just stops for no apparent reason before continuing on its merry way lol.

    Print speeds ranged between 30mm/s and 120mm/s (the bowls were 120mm/s, the object in the picture was 80mm/s). Would love to know if there is some other setting that needs to be altered in the configuration files that 'smooth' things out. I'm wondering if maybe this is caused by it needing to accelerate to get to speed, then suddenly decelerate as it reaches the halfway mark. This is what made me change around the acceleration setting, but as I said, doubling and halving did nothing.

    Any ideas? 😄



  • DISCLAIMER newbie alert LOL might be retract issues, looks like it is leaving a glod at the start\stop point. some slicers have a "align" or "random" setting try random and see if issue changes to all over print. if so i think it is retraction issue



  • I thought that too, but my retract is nearly 8mm lol, and it is set to align nearest. XD If I have to retract any further, I risk the tip being too deformed to push back through the nozzle XD



  • Can you upload a sample gcode? and which slicer do you use?



  • prusa's slic3r version 1.35.5

    https://www.dropbox.com/s/fioutqfmadsek5p/Pitch%20and%20Roll%20Plate.gcode?dl=0 here ya go. The file for the print in the picture



  • you just described my problem to a t! i have retract of 15mm and am seeing a jamming issue from the blob on end of filament not going back in… ugh hopefully this topic will fix both our issues LOL i have tried cura, slic3r and prusa slicers all same result. been watching that pressure advance topic too, very interesting and i am guessing the future of 3d printing...



  • @FrankNPrinter:

    you just described my problem to a t! i have retract of 15mm and am seeing a jamming issue from the blob on end of filament not going back in… ugh hopefully this topic will fix both our issues LOL i have tried cura, slic3r and prusa slicers all same result. been watching that pressure advance topic too, very interesting and i am guessing the future of 3d printing...

    15mm is an awful lot. How long are you Bowden tubes. What can happen when you have that much retraction is that you draw hot molten filament up past the heat break where it solidifies ad causes a blockage.



  • While not exactly addressed to me, figured i'd throw in 2 cents. My bowden tube is maybe 1 1/2 feet long, Using a E3D V6 (real one) and only do the 8mm retract because of a PETG I used to use that would ooze like CRAZY. Just never bothered to move it back down to 5 because at 8, it still seems to work with this PLA.



  • @HikariNoKitsune:

    While not exactly addressed to me, figured i'd throw in 2 cents. My bowden tube is maybe 1 1/2 feet long, Using a E3D V6 (real one) and only do the 8mm retract because of a PETG I used to use that would ooze like CRAZY. Just never bothered to move it back down to 5 because at 8, it still seems to work with this PLA.

    In your case, I don't think the pause during perimeter is anything to do with retraction, as retraction should only happen before non-print moves - not in the middle of a move. So I'm still thinking about that. Yes I've had similar issues with PETG, even E3D's Edge likes to ooze of it's own accord. I found pushing the print speed up - especially non-print moves helps. I mean like 350mm/sec for non print moves. The less time it has to ooze, the better. I'd recommend that you put the retraction back down to 5 for the reason outlined above, but it isn't the cause of your pausing during print moves. When it happens, have you tried running M122 to see if that throws anything up. Thinking about it, it might be worth doing in nay case and post the result.



  • No idea what M122 is =D Is that something I can just send to it while its printing I'm assuming (based on whatcha just said)? And my non-print moves are 250mm/s I believe. Let me check. Nope, 230mm/s it seems. I've been slowly ramping that up (it used to just be 80mm/s) to see just how fast it'll move, but its gotten to the point where i'm worried that it'll shake the whole printer lol. Though maybe not, it isn't quite doing it yet, so I could bump it up and find out! >=D

    The thing that baffles me though, is that when its doing infill, it doesn't do it. Both solid infill and normal infill. It only does it on perimeters.



  • Here is a pastebin of 3 different M122 calls. One while it was doing infill, one while it wasn't doing a stutter, and one as close to the stutter as I could manage.

    It is in the order of:
    Top - Stutter
    Middle - No Stutter
    Bottom - Infill

    https://pastebin.com/Yy7rjzHP


  • administrators

    Are you printing from SD card, or via USB? If via USB, what program are you using on the PC to send the gcode?



  • Printing via SD card I'd believe. I log into the web interface, upload a gcode file, hit 'print'.

    Also, I'd like to say that this is probably the ONLY forum I've ever been on, when the actual people who developed and work on the things the forum is about, are actually always around and generally seen in every thread lol. Its rather awesome to see!



  • @deckingman:

    @FrankNPrinter:

    you just described my problem to a t! i have retract of 15mm and am seeing a jamming issue from the blob on end of filament not going back in… ugh hopefully this topic will fix both our issues LOL i have tried cura, slic3r and prusa slicers all same result. been watching that pressure advance topic too, very interesting and i am guessing the future of 3d printing...

    15mm is an awful lot. How long are you Bowden tubes. What can happen when you have that much retraction is that you draw hot molten filament up past the heat break where it solidifies ad causes a blockage.

    Thank you Sir! I am still a bit of a newbie. (FT5 with duet wifi) bowden is about 1.5 feet but goes through enclosure as extruder is outside. It has slack in it so it is not straitened out at max x or y movement (now thinking i should shorten it up a bit)I am seeing a great deal of wear on the ptfe tube where it connected to the e3d hot end. When jams occur i am seeing filament about 1 inch past end of bowden tube when i pull it out of the print head. It appears to be pushing bowden slowly out of retainer. after running a long print, tube will have bite marks from retainer digging into it. that may be because of the blob on the end of the filament so you are certainly on to something!



  • forgot to add all metal hotend no ptfe tube inside



  • @FrankNPrinter:

    @deckingman:

    @FrankNPrinter:

    you just described my problem to a t! i have retract of 15mm and am seeing a jamming issue from the blob on end of filament not going back in… ugh hopefully this topic will fix both our issues LOL i have tried cura, slic3r and prusa slicers all same result. been watching that pressure advance topic too, very interesting and i am guessing the future of 3d printing...

    15mm is an awful lot. How long are you Bowden tubes. What can happen when you have that much retraction is that you draw hot molten filament up past the heat break where it solidifies ad causes a blockage.

    Thank you Sir! I am still a bit of a newbie. (FT5 with duet wifi) bowden is about 1.5 feet but goes through enclosure as extruder is outside. It has slack in it so it is not straitened out at max x or y movement (now thinking i should shorten it up a bit)I am seeing a great deal of wear on the ptfe tube where it connected to the e3d hot end. When jams occur i am seeing filament about 1 inch past end of bowden tube when i pull it out of the print head. It appears to be pushing bowden slowly out of retainer. after running a long print, tube will have bite marks from retainer digging into it. that may be because of the blob on the end of the filament so you are certainly on to something!

    Yea, you're retracting WAY too much. Try 5-6mm. 15mm is pulling it completely out of the nozzle and into the 'wider' section of the throat, where it then solidifies into a larger piece and wont ever go back in. And yes, this will cause the tube to be forced out of the retainer if your stepper motor's amperage is too high.



  • OP. What sort of printer is it? By that I mean is it Cartesian, CoreXY, Delta? Does the pausing on perimeters happen in the X direction, the Y direction or both? From your diagnostic reports, the supply voltage looked a little low, dropping to 10.9v. It's not triggering any under voltage events but I'm wondering if it might be cause a stepper to stall? DC42 will know if that's a possible cause better than me.



  • I do know that my powersupply is complete garbage. It is supposed to be 12V but when idle it'll be around 18V and then drop as low as 10V when any sort of current is pulled through it… its been a pain to work with... adjusting the pot on it doesn't even change the voltage like it should... But it has been 'working' for nearly 2 years now, and havent' felt the need to really replace it since it's been performing (although just barely). Been thinking about getting a switchable powersupply (as in, one that can be turned on and off by the duet instead of staying 'on' all the time. any decent suggestions?

    Also, it is Cartesian. It is a self made Prusa i3 MK2 style.



  • any of the "certified" pc power supplies are more than good enough, and some even do power filtering which is huge for DC stuff! you can buy an atx adapter if you don't want to do any wiring on the PS unit for remote on. I believe Aux power on off can be used to turn on 2nd power supply from duet wifi but have not tried it. it is mentioned in another thread if you search, i think m80 or 81 for on off…



  • @FrankNPrinter:

    any of the "certified" pc power supplies are more than good enough, and some even do power filtering which is huge for DC stuff! you can buy an atx adapter if you don't want to do any wiring on the PS unit for remote on. I believe Aux power on off can be used to turn on 2nd power supply from duet wifi but have not tried it. it is mentioned in another thread if you search, i think m80 or 81 for on off…

    Yea I'm going to have to give it a look once I can get some more money going. Sadly, I don't make all that much lol. Maybe $280 every two weeks. So as you can imagine, buying a Duet WiFi is literally over half my paycheck… So I'll give things a look around to see if I can find something. I've always liked the ability of using a ATX power supply from computers (its what I used to power on the printer during the first few months of it being 'alive', but it took two of them, one for the board and hot end, and one just for the heated bed... they were powersupplies from the mid 90s lol), so I've been thinking about trying out the whole 'server power supply' idea. I have a few lying around that came as extras with a HP Proliant server and Dell Poweredge server. Just haven't really been too keen on opening one up because I know they can handle alot of power and sometimes really high voltages...


 

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