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Ugly first layer  

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Tobias
(@tobias-2)
Active Member
Ugly first layer

Hi folks,

I don't know how to achieve a proper first layer with my Prusa MK3S+.

I have leveled the bed a thousand times but it never really works out well (Z is at around -1.4). Sadly, not even the prusa test pattern, that is stored on the shipped sd card will come out correctly. At any point of time (usually the 3rd or fourth roundtrip on the first layer), the extruder rips off the already printed lines.

The attached image shows a typical first layer. The uneven surface cause trouble when continuing the print.

Desperately looking for your help.

Tobias  

Best Answer by Peter M:

@tobias-4

Hot water with dish soap clean 100%, alcohol does not.

If you clean with dish soap the first time, do it a few times. Then your bed is like new.

A few prints you can do with alcohol then do with dish soap again.

 

This prevents the filament sticking to nozzle, like a ball or spaghetti, because model did not stick.

 

Posted : 28/03/2021 12:08 pm
Tobias
(@tobias-2)
Active Member
Topic starter answered:
RE: Ugly first layer

I should have mentioned that this is Prusament PLA Jet Black filament, not older than 3 month.

Posted : 28/03/2021 12:22 pm
Tobias
(@tobias-2)
Active Member
Topic starter answered:
RE: Ugly first layer

Sliced with PrusaSlicer 2.3, default Prusament settings (215°C / 60°C)

Posted : 28/03/2021 12:30 pm
Peter M
(@peter-m)
Noble Member
RE: Ugly first layer

You are to low, your filament has waves(like water), then you are to low.

Needed to get a good print:

1. Clean bed, dish soap is the best, and use a lot af hot water(do several times).

2. First layer make this 100%.

Setting in printer , 7x7 calibration is better.

If first layer does not work, this is what I do:

Clean, start to print a few squares, start the first layer to high, and go slowly down, then you see the good setting.

Posted : 28/03/2021 1:17 pm
Tobias and Dan Rogers liked
Tobias
(@tobias-2)
Active Member
Topic starter answered:
RE: Ugly first layer

@peter-m

Ok. Will try to raise it a bit. I cleaned the bed with alcohol but not with hot water. Does this make a difference? 

Posted : 28/03/2021 6:52 pm
Peter M
(@peter-m)
Noble Member
RE: Ugly first layer

@tobias-4

Hot water with dish soap clean 100%, alcohol does not.

If you clean with dish soap the first time, do it a few times. Then your bed is like new.

A few prints you can do with alcohol then do with dish soap again.

 

This prevents the filament sticking to nozzle, like a ball or spaghetti, because model did not stick.

 

Posted : 28/03/2021 8:52 pm
bobstro
(@bobstro)
Illustrious Member
RE: Ugly first layer
If you have not already done so, try using Jeff Jordan's "Life Adjust" procedure for calibrating your Live-Z setting. It is much easier to use and understand than the onboard routine and much easier to make mid-print adjustments accurately with. In general, start high (less negative) and work lower (more negative) in large increments (e.g. 0.1mm) until the filament starts to stick on its own. When you've got your Live-Z setting adjusted properly, you should be able to gently rub the extruded lines on the PEI surface without dislodging them.  Then start lowering (more negative) the level until there are no gaps between layers. You should not be able to peel the lines apart after printing, but the top should be regular. 
My notes and disclaimers on 3D printing

and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

Posted : 28/03/2021 9:28 pm
Tobias liked
Tobias
(@tobias-2)
Active Member
Topic starter answered:
RE: Ugly first layer

@peter-m

Incredible. 
I assumed, the dish soap cleaning method would be an inexpensive alternative to alcohol only but unlike Prusa recommends, it is THE way to go. 
Alcohol apparently makes things worse.

Posted : 31/03/2021 3:17 pm
ssill2
(@ssill2)
Noble Member
RE: Ugly first layer

@tobias-4

Yes, I was having a similar problem a few months ago and Swiss_Cheese and others helped get me dialed in.  The dawn + a light scrub works great.

Assuming the dialed in zOffset,
On PEI(smooth) sheet aftwards, PLA needs nothing to make it stick.
PETG you apply a little windex to the PEI to act as a release agent after the print completes.
TPU, some glue stick works fine.

I found that the zOffsets for different types of filament(PETG/TPU/PLA) can differ a bit and you can use the printers ability to define different steel sheets to quickly switch between them.  In my case I have Spla, Spetg and Stpu  for the  the smooth sheet with pla, petg and tpu respectively.  you can do the same for the textured sheet.  See this link for setting the separate profiles up.

https://help.prusa3d.com/en/article/steel-sheet-profiles_1955

 

 

Posted : 03/04/2021 3:19 am
hawai
(@hawai)
Reputable Member
RE: Ugly first layer
Posted by: @ssill2

I found that the zOffsets for different types of filament(PETG/TPU/PLA) can differ a bit and you can use the printers ability to define different steel sheets to quickly switch between them.  In my case I have Spla, Spetg and Stpu  for the  the smooth sheet with pla, petg and tpu respectively.  you can do the same for the textured sheet.  See this link for setting the separate profiles up.

But always start from zero or at least from quite high up and remember to check them all again after you did  a new calibration.

I made the mistake of using a stored value as starting point that was actually way too low. This ruined part of my textured sheet as it generated a square that was squished so deeply into the textured sheet, that it was impossible to remove it.

Posted : 05/04/2021 2:58 am
cwbullet
(@cwbullet)
Member
RE: Ugly first layer

@hawai

You will hopefully only make that mistake once.  It is a learning lesson that nearly all of make. 

--------------------
Chuck H
3D Printer Review Blog

Posted : 05/04/2021 8:55 am
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