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Quality dropped and I can't fix it.  

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Inflamedsebi
(@inflamedsebi)
Active Member
Quality dropped and I can't fix it.

Hey, I m having trouble getting the quality back up to where it was a while ago.

I m finally familiar enough with printing to start making my own D&D minis, but I want them to be as clean as possible before post processing, so I used this test to have an overview on where to tweak it: https://github.com/kickstarter/kickstarter-autodesk-3d

 

Some tests where good: dimensional accuracy (5/5), fine flow control (2.5/5 ->only minor stringing), fine negative features (4.5/5).

But some tests could be better and I'm convinced it wasn't always like that, but I have no clue how to troubleshoot further ...

 

Bridging could be better, but is actually fine ... I might decrease temperature just a bit so stringing should be gone and might even help with the overhangs:

Now the stuff where I have no clue on how to improve it.

There is some ringing on the x and y, hard to see in the photo, but noticeable on the print:

And the the biggest problem: z-alignment of layers is bad:

Even at 0.2 layer high it should not be this inconsistent. And I have prints from just a few months ago, that did not have this issue at all, Z was always perfect for me, but now I got this 🙁

Belt tension is: 288 on Y and 268 on X; Pulleys are tightened; Bed adhesion is fine and there are no skipped steps/layers, no oozing.

Filament is https://www.dasfilament.de/filament-spulen-xxl/pla-1-75-mm/118/pla-filament-1-75-mm-2600-g-grau?c=19

Using stock profile for generic PLA.

Printer is a MK3s, no modifications worth mentioning.

Thanks for your time and help in advance 🙂

Posted : 15/10/2019 9:22 pm
Nikolai
(@nikolai)
Noble Member
RE: Quality dropped and I can't fix it.

Looks like you have mechanical issues, like something is loose.

1. Belt tension: Do not rely on the values. They are not accurate and not being updated all the time.
2. Make sure extruder is cold! Grep the extruder with one hand. Try to move the nozzle with another hand in any direction.
3. Verify all other gantries and moving parts
4. Verify all rods and bearings. Especially the ringing indicates that something is bouncing freely

Hope that gives you some direction where to start.

Often linked posts:
Going small with MMU2
Real Multi Material
My prints on Instagram

Posted : 15/10/2019 9:45 pm
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(@)
Illustrious Member
RE: Quality dropped and I can't fix it.

Ringing is usually belt tension: the tension numbers are garbage in garbage out info: ignore them.

Measure belt tension with a deflection gauge or scale.  Apply 6 ounces force mid lower belt, you should see 15/64" on X, and 12/64" deflection on Y.

Belt Tension Calculations

This post was modified 5 years ago by --
Posted : 16/10/2019 12:21 am
Inflamedsebi
(@inflamedsebi)
Active Member
Topic starter answered:
RE: Quality dropped and I can't fix it.

1. Ok, I did test and then tighten my belt on the x (since this is easy on the mk3) and ringing is gone now ... I guess y has the same issue but I have to print the belt tensioning system for y first 😉

2. Nozzle/whole extruder is stiff and does not wiggle at all.

3./4. everything that should move, does so consistently and freely, like it should be. Bearings are lubricated and silent.

One thing I did not recognize ... I changed my filament manufacturer ... maybe the new filament is just inconsistent ... I'll check that too and get back here later down the week.

Posted : 16/10/2019 4:15 pm
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