Strange Problem

I’m trying to print a figure of Darth Vader over and over again and get one fail after the other. This time it’s really strange. It seems as if the X-axis shifted suddenly to the left and then kept on printing normally. I sliced with Simplify 3D. This is the first time I saw this problem. Print is not finished, because I stopped after recognizing. Any idea what this could be about???

It could be that the nozzle struck the print and shifted either the print itself or the magnetic bed. (Enabling or increasing z-hop is usually the recommendation for preventing that.)

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I second @ElloryJaye’s recommendation. What layer height were you printing with? I’ve had bad luck with thinner layer heights than .16mm, even with z-hop due to the thin layers curling up and then getting struck, causing a layer shift.

Layer was 0.16 mm. Z-Hop is active (0.5 mm). I doubt that the figure was shifted. The material of my printsheet is really awesome. Is is nearly impossible to remove the PLA until the bed cooled down. The sheet is glued on a 5 mm aluminum plate, which itself is glued on a ferro foil. So there is no movement at all. Beside of that, if the figure would have moved, I don’t think it would stick again immediately to the sheet, as the layers after shifting are aligned good again?!

Oh wow sorry, yea you’re right. I missed the whole part where it comes back.

Were you watching this print during the time it has the glitch? It sort of looks to me like Z just decided to go up a bit? Or maybe a few layers in the middle didn’t print due to a temporary clog? I really am not sure here.

Could you post the factory file from S3D?

My fault. It‘s really hard to see, but the Problem is that suddenly the Z-axis was shifted to the left (minus on X-Axis).

I do the upload later when I‘m back Home.

Here is the factory file and the gcode from S3D:

and two more pictures to show the issue:

I see some issues with the gcode and support placement.

Generally, for complicated prints like this, I look at the gcode preview layer by layer and make sure there’s nothing that begins printing in mid air.

There’s a lot of support that starts printing from the model, which is very difficult on these steep angles.

This support just begins printing in mid air.

There’s lots of examples of support that I don’t think will adhere to the model. Automatic support generation is a good place to start, but it needs a human brain to make sure that the support is really printable, otherwise stuff like this happens.

I’ve found the S3D supports are great for geometric things with flat or shallow edges, but for models like this you might have better luck slicing in Cura with Tree Supports enabled. It generates support that looks like this:

Tree supports are great for models like this because:

  • They always start on the build plate and never start inside the model, improving surface finish.
  • They should be able to be removed in a single piece

This is kind of a stretch, but I think some support was printed midair, ultimately leading to a nozzle crash that shifted the layers. And at some point there was another crash that knocked it back, but it was random chance. ?? Not sure why it came back.

Going forward, I think you need to follow the recommendations of this article. I don’t much experience printing things like this, so I’d rely on the tips in here:

Best of luck, if you can get it to work, please update with what you changed!

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Hey, I had similar issues two times, I guess this comes from a fail of the x linear module.
My problem disappeared after intense testing under max heat and motion for about 5hours or so.
I would suggest you to check the blue pad of the linear module, - there are a lot of topics in the forum.
Hope this helps!

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Thanks, Brent and thanks Chris,
It has to be said that the support here is really awesome! I really appreciate that you guys spending so much time in solving issues, noobs like me are having. Thank you very much!

I assume Chris is right, I don’t see another plausible explanation for that. I right now don’t now what you meant with the blue pad of the linear module, but I hope the problem won’t come up again.
I did a re print of the same file, fortunately that worked.
@brent113: Very good point with the support structures! Even with the working print some support columns (probably that ones I manually added) did not stick to the model. You delivered the reason, thanks! In fact, I just used the tree structures once and it was a mess. I think I have to have a second look at that feature…


Hey @FlyByWire , i would suggest you to @xchrisd if you really want to reach out to people,- the chance to loose some topics is minimized then.

I meant the heatsink-pad of the linear module, have a look at this:

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