Shiny spots (PLA)

Bambu Lab X1 Series
1

Just wanted to ask why my pla prints have this shiny spots? The prints look awesome but sometimes i have this shiny spots and i don’t know why or how to get rid of it! Must be 3-4 layers i would say.

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2

Different printing speeds cause this, so the material starts to appear different.

You can solve it with the following:

  • set layer time in the filament settings much higher - that everything is printed at the same slow speed
  • set layer time to 0 - that everything is printed very fast
  • set max print speed to something lower - layer time is respected
  • print another tower/cube next to it - layer time is respected
2 Likes
3

Could also be heat fluctuations, temperature differences can cause a color/surface finish difference.

4

Okay, but why its only on one place or two? Thats strange.

5

Read my post - slice the model in the slicer with the same settings you printed it already and check the printing speed in the preview. I’m almost certain it’s different printing speed on these layers.

2 Likes
6

I will check it out, thanks.

7

Did you print with the door open? If no : Did you open the door when you were printing?

Because when you were printing with closed door and if you open it you have shinier layers.

So : when you’re printing you must open the door or keep closed but not the both.

8

Yeah its always closed!!!

9

Is it Silk filament? It is hard to print it without defect. Try to open your door to have less heat inside the enclosure. it looks like at a variation heat problem

10

My thought was that the temp fluctuations were occurring while those layers were printing.

Do you have a lid vent while printing PLA?

11

Its differences in the layer time. Ive done some testing and it appears for me on any layer thats printed that takes less than 15 seconds will appear more shiny than layers that take above 20 - 25 seconds.

If I slowed down the print it mitigated this but only up until 150mm/s any slower and the shinyness comes back.

The the “fix” is to try to pad out the layer time. You can do this by adjusting things like innerwall speed and infill speed to be slower. I found that if I increased the per layer time minimum to be 20 seconds then the banding goes away.