Hello! Sorry, forgot the 3mf. Here it is: FSR_2024-04-08 (4) Fot seam test.3mf
The reason for the spine is to be able to get a straight seam on the feet. Without the spine the seam is not straight. Maybe there is an easier way but this spine is not visible when printing and allows the seam to be straight.
1 hour ago, Theo123 said:The reason for the spine is to be able to get a straight seam on the feet. Without the spine the seam is not straight. Maybe there is an easier way but this spine is not visible when printing and allows the seam to be straight.
Makes sense. Nice thinking 😉
So looking at the photos it looks like it's the first layer after the top of the main body finishes. Nothing strikes me as unusual at first glance:
Looking at the photo though, what seems like a giveaway to me is that while the side view of your model shows a perfectly straight line:
Your photo from the side (well it's not 100% perfectly the side but it's more than good enough) shows that it's not just that layer that has a problem, all the subsequent layers follow its line instead:
This almost certainly means it's a layer shift, which is when for whatever reason either something causes the model to shift on the plate or the print head slightly loses its place. You can see that layer looks slightly different. The model should be fairly well anchored by now, so my first stop is one of the things which often causes it: speed.
Okay, so the speed is fine. What about acceleration?
This is... not what I'd recommend. Printer manufacturers (especially Chinese ones) seem to be in a pissing contest about the highest possible printing speed... which you can only actually do with specially designed super high speed PLA.
The good thing is you've set your speed well. But accelerating this fast isn't good a lot of the time. I'm not at all familiar with your printer, but if something isn't at the correct tension, acceleration this fast can cause something to slip a couple of steps on the stepper motor (which means the print head is no longer where it thinks it is). So if there's anything you can adjust (like the tension on belts or something) make sure it's correct... I can't really offer more help than that unless you want to buy an Ender-3, those I know how to maintain.
My printer (Ender-3 V3 SE) can only accelerate at up to 2500mm/s² but that's actually been fast enough to drag parts of a model with it when it started doing a long travel move (which warped that section a bit). I'm sorta paranoid so I lower the max acceleration for everything (including travel) to 500mm/s². I actually wrote my own post-processor so I could slow down the speed it prints support and the next travel move afterwards (you can set the speed for support, but if you have a fast travel, it can still rip support off when it goes zooming, especially given I print support with a bit lower flow) - you don't need to be that paranoid, I'm just weird. I certainly wouldn't go above 1000mm/s² (and whatever you do, do half that for the initial layer). This is obviously the first layer where it has long travels to weaker bits, so it's the place this is most likely to happen.
The other component is jerk: I see you have jerk control turned off, nothing wrong with that since it's not a problem a lot of the time. Jerk is how much it's allowed to instantly to change speed, because for example at a corner you can't just slow down, stop on the corner and start accelerating in the new direction since it'll leave a blob in the corner, so it just slows down enough for the jerk to allow it to go to the corner and then start moving in the next direction at the jerk speed. This is another great opportunity for something to slip out of place if your jerk value is too high. I'd try enabling jerk control and setting it to 8mm/s.
Slowing the acceleration and lowering the jerk will increase your print time, but remember: good print > quick print.
Well this is all my theory, at least 🙂. For all I know I'm completely on the wrong track but this is problem solving in a nutshell: test something to see if it's the cause of your problem, and if it isn't, find something else to blame.
Slashee's Suggestions:
Now, because I can't dig through peoples' print settings and not find stuff I think could be improved, consider these:
@Slashee_the_Cow Hi again,
I am still having the same issue with the layer shift beginning at layer 55 after trying all the different recommendations.
I have some thoughts. Can I exclude hardware issue since I only get this issue on this specific model or could the tightness of the belts be a cause?
I am also considering to maybe do some sort of script adjustment to try and see if that might help. I was thinking that maybe "ChangeAtZ" and changing lets say speed to something much lower from layer 55 and onwards might help? What do you think, is this something worth trying?
Do you have any other advice on how i can continue to troubleshoot? Or do you thing that maybe it's time to change the model and perhaps have more square legs or bigger legs in the model? Although i really would like it to have cylindrical legs.
I have also seen on some versions I've tried that the layer shift only occurs at layer 55 and then goes back to the correct layer build, meaning that only layer 55 is "overextruding" and the subsequent layers seems to be just where they are supposed to be.
Just a bit desperate to solve it but I'm stuck again.
Br,
"Can I exclude hardware issue since I only get this issue on this specific model "
Not yet. But you need to look at your settings as well.
I know the colors aren't good here and it's kind of hard to see.
This is the gcode read into AutoCAD. The red lines are the Outer Walls of the gcode file. You can see that the bump doesn't exist here and the Cura preview also reflects this. That's why I'm thinking that the possibility of a printer problem shouldn't be discounted yet. BUT it could be the way the printer is responding to the commands it's getting.
I also read the Gcode into MS Excel, the line widths are all 0.48 thru that area of interest and that is your setting.
Since the line widths are consistent through those layers-of-interest, and the layer height is consistent, and the toolpath is consistent, it could well be a printer problem. (Only having the problem on this one model would say it isn't a printer problem).
It may be significant that the problem seems to occur when the model goes from a single piece, to three "islands" when the legs start.
In regards to the settings - I agree with Slashee that they are all over the place. You need to go back to a simple, consistent set of settings so you have a baseline to work from. I won't go further into it, but yeah, a minimum line width of 0.01 is just silly. Printing PLA at 230 would seem to be way too hot, but all printers are different and your thermistor may be reading incorrectly and needs to be compensated for.
This is how I'd set up the slice. I sort of used your numbers but don't simply print this without checking things like the print temperature.
Thank you @GregValiant. I will try the profile.
Edited by Theo123Don't worry, you're not the only one who's run out of ideas of what something could be 🙂 . Unfortunately yours is the bad version, the good version is when you look online, find the answer within two minutes and feel like an idiot.
It's worth doing a test where you select the model, open the move tool, turn off Drop Down Model and move your model down through the floor so that it's only printing a few layers before it gets to this bad one, not that it should have too much to do with height (that I can think of) but it never hurts to rule these things out. Also if it has the same problem... well run your tests on that and save yourself some time and filament 😄 . If it doesn't have a problem then it means it's probably your printer.
You can't exclude the hardware because this model is somewhat unique when it gets to that layer - instead of doing a whole model at once, it's doing three singular islands. The tightness of the belts could be a cause: when it's doing a fairly fast travel between those islands, it could slip a bit.
ChangeAtZ doesn't have as many options as I'd like (which isn't really a problem with the script, it's just that I'm such a control freak I'd want all the options) but you could try setting it to slow down to a crawl (and I mean really crawling, this is just going to the extreme for a test) for layer 55:
@GregValiant: Probably easier just getting the project file and changing all the print settings in that. Profiles... like most parts of Cura... can be a fickle beast.
@GregValiant Hi, your profile seems to improve the print. Thank you. I still have a slight layer shift at the same place when the model goes into the "island section". Any suggestions on how i can adjust for this?
Br,
Here are some pictures of the result with your profile @GregValiantIMG_8970.pdfIMG_8972.pdfIMG_8971.pdf
The islands are way more brittle now than they were withe the previous settings.
Can I also adjust the seam in a nicer way? Can't seem to get it as straight as i did before.
Edited by Theo123
There really shouldn't be anything different just because there are islands.
I'll think about it but off the top of my head, whether it could be something in the settings or a hardware trick that is in the the printer, I don't know what could cause that.
If you printed cooler than the 230 you had, then the plastic will have reacted differently. PLA is by nature very brittle.
If you make the seam location the mid point of your build plate then the seams on the legs should face inward. That's about the best you can do. Your build plate is 202 x 202 so make the X and Y of the seam location 101 and 101.
Lets go back to the beginning here. What kind of printer is this? You've called it a Betaminion, but I don't see it come up in my search.
It is a FL SUN Superracer
I look at too many of these things and I got two projects mixed up.
OK. It's a good name brand printer. I'm not familiar with the mechanicals on a delta though.
Do all the legs show that layer shift? Are they all moving away from the seat centerline like the one in the image?
Yes, more or less. There can be a slight difference between the legs. One can be "more shifted" than the other two vice versa. Not with consistency though.
I'm leaning towards the printer.
I keep the tail ends of filament rolls around for things like this.
On the left is your original project, printer, and profile. I adjusted my home offsets to account for the Origin at Center of your delta printer.
On the right is my setting profile. Both were printed on my Ender 3 Pro (cuz that's what I've got.)
I know my camera isn't great, but I don't see the step on either of them even under a magnifying glass. I'm starting to think that maybe the long travel moves between the legs are having an effect. Maybe there is some shaking or something going on.
It might be worth your while to do a preventative maintenance check on the mechanicals. Things can come loose, get out of adjustment, whatever. It may help, and it can't hurt. I have a regimen I go through once a month and I always find something that needs re-adjusting.
In regards to settings, you might try changing the infill from gyroid to grid (not as much motion) and consider dropping the Acceleration from 5000 to 1000. I know your machine can handle the 5000 - but maybe not today.
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Slashee_the_Cow 479
Hiya!
It's always easiest if you can post a Cura project file (.3mf, in Cura set it up ready to print then go to File > Save Project) that way it sets up an instance of your printer and copies all the settings in as well as the model.
Is it just one column you're having trouble with or all of them? Because looking at the STL I see that they all have a thick spine for some reason:
But for one of them that line also goes around to the side and then down the edge:
Or is that intentional? I have no idea what you're trying to make 😕
Also (and I'm not saying this is your problem but it's good practice) when I imported your model into Cura I got a warning that it wasn't watertight. Thankfully there's an awesome plugin called "Mesh Tools"
With that installed, I had to do was right click your model and select Mesh Tools > Fix Simple Holes and it fixed that problem.
I'm happy to do a more detailed look into it but that's probably not a good idea at 1:30AM so I'll get back to you later on that one 🙂. If you could post the Cura project file it'll be a lot easier to see how you've got it set up.
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