Inconsistent color with Prusament PLA?  

  RSS
Marc
(@marc-16)
Active Member

I printed a cat-in-a-box figurine on the Prusa Mini last night using Prusament PLA in Opal Green. (As people have discovered, the Prusa Mini is particular about which filaments it can use.)

I noticed something interesting when looking at my print this morning. On the left side, it looks fine:

But, the right side of the cat has this very distinct striping.

What can cause this disparity in how the color ends up presenting itself from one side to the other? Since the part cooling fan is coming from the back, I wouldn't expect it to affect the left and right sides differently.

Posted : 13/01/2020 2:54 pm
Texy
 texy
(@texy)
Reputable Member

Unable to view those images Marc !

Posted : 15/01/2020 3:11 pm
Marc
(@marc-16)
Active Member

Ah, thanks for letting me know! They show up for me, so I've got a permissions issue there.

Here they are again:

[caption id="attachment_10228" align="alignnone" width="600"] Cat in box showing normal coloring.[/caption]

[caption id="attachment_10225" align="alignnone" width="600"] Cat in box showing mysterious color striping.[/caption]

This post was modified 1 year ago 2 times by Marc
Posted : 15/01/2020 3:15 pm
Texy
 texy
(@texy)
Reputable Member

I can see the mages, and the banding. Can't help with the issue though 🤨 

Posted : 15/01/2020 3:39 pm
Marc
(@marc-16)
Active Member

You still helped with a very useful base diagnostic issue with my post! 😀 

Posted : 15/01/2020 3:57 pm
PJR
 pjr
(@pjr)
Moderator

Temperature variance can cause this.  Even just a few degrees.  You could try increasing the print temp by 3 degrees

Or a slight porosity when printing due to filament not being dry or inconsistent feed. Try with new filament spool and make sure that the filament path is smooth.

I have printed that model from Loubie many times (mainly with MMU) and not had those issues at all.

 

Peter

Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…...
Posted : 16/01/2020 3:38 pm
Sfbrain
(@sfbrain)
Estimable Member

Just a thought, but ........

That looks like a semi transulcent filament, if thats the case then the 'infil' may be effecting the colour appearance.

If you have used 'gyroid' infil then the density of your print at the edges will vary with the infil and possibly effect its translucency.

If this is true, try a consistant 'infil' like rectilinear.

Just athought

S

This post was modified 1 year ago by Sfbrain
Posted : 16/01/2020 5:18 pm
burtronix liked
Marc
(@marc-16)
Active Member
Posted by: @pjr

Temperature variance can cause this.  Even just a few degrees.  You could try increasing the print temp by 3 degrees

Or a slight porosity when printing due to filament not being dry or inconsistent feed. Try with new filament spool and make sure that the filament path is smooth.

I have printed that model from Loubie many times (mainly with MMU) and not had those issues at all.

 

Peter

Well, the spool was opened just fresh for these new prints from the Prusa Mini. (I had tried using a different filament and ran into jams, so I switched to Prusament for the most reliable tests.) I would hope it wouldn't have any moisture issues straight from the bag.

Still, temperature could be a problem, I suppose. It's printing at 215 using the Prusament PLA profile.

Posted : 16/01/2020 5:25 pm
Marc
(@marc-16)
Active Member
Posted by: @steve-4

Just a thought, but ........

That looks like a semi transulcent filament, if thats the case then the 'infil' may be effecting the colour appearance.

If you have used 'gyroid' infil then the density of your print at the edges will vary with the infil and possibly effect its translucency.

If this is true, try a consistant 'infil' like rectilinear.

Just athought

S

I don't think this is a translucent filament. Prusa's shop page doesn't mention that. Still, I might try increasing the number of walls and see whether that makes a difference.

Posted : 16/01/2020 5:26 pm
burtronix liked
bobstro
(@bobstro)
Illustrious Member

Riffing off @pjr & @steve-4's suggestions:

  • Infill can definitely affect external appearance. You might try holding that piece under different direct and back lighting to see if there's any difference. Based on what I can see in the pics, it seems to get lighter on curved "shoulder" shapes towards the top. That's an area that will usually see increased infill and wall thickness.
  • Consistency of speed and extrusion rate can cause variations in print surfaces and appearance. You might try a small test piece -- perhaps a 20-40mm sphere -- with the same filament and experiment with speeds. Try printing external perimeters at a slower speed -- I use 25mm/s -- to see if it produces more consistent results.
  • Nozzle temperature variations can come into play, especially if you get drafts during the cold winter months. Consider adding a silicone sock to protect the heater block from varying temps, or even put the printer in an enclosure or put up something to block drafts.

If  you'd care to save a 3MF, zip it and upload it here, we can look over your settings and possibly make some more suggestions. 

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 : 16/01/2020 5:36 pm
burtronix
(@burtronix)
Estimable Member
Posted by: @steve-4

Just a thought, but ........

That looks like a semi transulcent filament, if thats the case then the 'infil' may be effecting the colour appearance.

If you have used 'gyroid' infil then the density of your print at the edges will vary with the infil and possibly effect its translucency.

If this is true, try a consistant 'infil' like rectilinear.

Just athought

S

Also try increasing the number of perimeter layers. Three might do it. 

Whatever you find to do with your hands, do with all your might!...
Posted : 04/02/2020 1:10 pm
JoanTabb
(@joantabb)
Moderator

As mentioned Sometimes infill can show though!

this was an insulated coffee cup holder printed in TPU, the air pockets in the infill reduced the heat transfer, and the crease lines allowed the holder to be squashed into a laptop bag pocket for storage!

 

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 04/02/2020 3:22 pm
Share:

Please Login or Register