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PLA Prusament color change change leads to blobs  

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olinjt
(@olinjt)
Active Member
PLA Prusament color change change leads to blobs

Hi, I love my printer.  Have used two Prusament filaments with no problems (Gentleman's Grey and Galaxy Silver).  I tried a test with Prusa Orange and it doesn't stick well to the pad, but sticks to itself and then to the printer head.  The sticker makes it look like it should work like the others...what's up?  I use alcohol to clean beforehand so not sure what it is.  After the problem I switched back to the Grey and all was fine.

First post, here!  I really love the machine and am happy that it worked great after assembly.

Posted : 29/10/2020 11:39 pm
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(@)
Illustrious Member
RE: PLA Prusament color change change leads to blobs

Print sheet type - smooth or textured? Print profile? Printer profile? Filament profile? 

Though in general, adhesion is sometimes game of chance. Some spools do really well, others of the same brand and color can perform differently. I've had Prusament that refused to stick. But later in that same spool the adhesion - remarkably - changed and became sticky again. I wrote it off to whoever packaged it had oily hands or had just slathered on hand lotion. 

Also - a photo of a failed print save a lot of time. I hear you'll need to make a few texts posts - then you can upload things. Some adhesion issues are more related to the layer one characteristics - and guessing what the real problem is isn't helpful and advice can mislead you into doing things you don't need to do. 

Posted : 30/10/2020 6:42 am
olinjt
(@olinjt)
Active Member
Topic starter answered:
RE: PLA Prusament color change change leads to blobs

Thanks for the info.

The print sheet is textured.  The Filament is 1.75mm PLA in all cases.  I printed using the default PRUSA logo plate.  I set the machine for PLA.  Not sure what else I am supposed to indicate when you describe "profiles"...being a newbie here.

Posted : 31/10/2020 12:45 am
JoanTabb
(@joantabb)
Moderator
RE: PLA Prusament color change change leads to blobs

@olinjt
Welcome to the forum. 
I understand you are having adhesion problems with Adhesion. 

Some folk say the textured bed is not good for PLA. 

I have quite good success...   

If that were My Build plate, 
I would take it to the Kitchen sink and give it a real good cleaning with hot water and a little dish soap, Dawn, Fairy liquid, some basic dish soap... nothing fancy. 
I would rinse and repeat, scrubbing left to right, Up and down, diagonally and in circles to try and make sure there is no surface contamination on the build plate,    Handle the build plate only by the edges and underside to ensure that you don't get any finger prints on the top. 

Rinse really well to remove all trace of dish soap, then dry immediately with a couple of paper towels. 

refit the build plate to your printer. 

Make sure that you are using 7x7 Mesh bed levelling (Available through the LCD Menu. )
now try printing again. 
 I understand that you are using the ready sliced Prusa nameplate. 
try that again. 
take a picture of the first layer please and drag and drop it into the bottom of the text input window, the window should change colour when you are in the right place (It's a bit of a pain, but you get the hang eventually...)

the profiles mentioned above are selected in Prusa slicer to try and select the best set of parameters for your prints. 
If you are using Prusament then you can select the prusament profile in the right hand panel. 

I would raise the bed temperature to say 65C or 70C, to improve adhesion. 

Good luck, 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 : 31/10/2020 1:47 am
olinjt
(@olinjt)
Active Member
Topic starter answered:
RE: PLA Prusament color change change leads to blobs

Thanks for the advice.  I'm in the midst of a small print now, which is going fine and will do what you suggest about the print bed.

I did notice that the prints that have adhesion problem are those where the first layer is very small.  Specifically, I tried one of the spiders, but reduced the size of the default model by 50%.  The eight little feet didn't stick and I'm guessing that there is a minimal amount of square mm needed at the base level?

Posted : 31/10/2020 1:58 am
olinjt
(@olinjt)
Active Member
Topic starter answered:
RE: PLA Prusament color change change leads to blobs

Oh...and I must say, again, I really enjoyed building the printer.  It was a very cool thing to do, especially in these days of social isolation.

Posted : 31/10/2020 2:00 am
JoanTabb
(@joantabb)
Moderator
RE: PLA Prusament color change change leads to blobs

@olinjt

are you aware that there is a minimum line thickness that can be printed on a 3D printer
often when you reduce the size of a model, some of the features disappear because they end up thinner than the nozzle can print. 
a 0.4mm nozzle is usually set to print 0.42mm first layer and 0.45mm higher layers. this often trips up, newcomers. 

Small contact areas are more difficult to print and therefore more likely to trip up a new user. 
also, sharp shapes are more likely to warp off the build plate than other features.
these models were printed on My Mk3S with MMU2S, the points were not adhering well, so I added 'Mouse ears' to the parts to help  keep them down... 
A brim would also have helped, but the brim takes more effort to remove... 

I am pleased to hear that you enjoyed building the printer. 
when you got to the point where you were installing the linear bearings, did you lubricate them or not?  I think the test in the assembly guide is misleading...   I Always lubricate my linear bearings. other folk have different opinions. (it's your printer, so your choice)

If you did not lubricate them,  please keep a watchful eye on your bearings, some folk find that after a short while, odd things happen like the printer having issues with the X or Y axis length or suffering unexpected collisions...   this can occur when the rust preventative oil dries out. 

Prusa suggest doing periodic maintenance and they supply a small tube if grease,  Check out the link below
https://help.prusa3d.com/en/article/i3-printers-regular-maintenance_2072#rods-and-bearings

Happy printing, 
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 : 31/10/2020 2:18 am
olinjt
(@olinjt)
Active Member
Topic starter answered:
RE: PLA Prusament color change change leads to blobs

 

I cleaned as suggested, but with a blue sponge.  Also raised the bed to 65C and so far so good!

Posted : 31/10/2020 1:36 pm
olinjt
(@olinjt)
Active Member
Topic starter answered:
RE: PLA Prusament color change change leads to blobs

And this is the final product...seems okay!

 

 

Posted : 31/10/2020 2:04 pm
olinjt
(@olinjt)
Active Member
Topic starter answered:
RE: PLA Prusament color change change leads to blobs

Strange...got a spaghetti monster in the end...  Doing it now with Gentleman's Grey PLA and all is well.

Posted : 31/10/2020 5:24 pm
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(@)
Illustrious Member
RE: PLA Prusament color change change leads to blobs
Posted by: @olinjt

Thanks for the info.

The print sheet is textured.  The Filament is 1.75mm PLA in all cases.  I printed using the default PRUSA logo plate.  I set the machine for PLA.  Not sure what else I am supposed to indicate when you describe "profiles"...being a newbie here.

Then you post this image:

That image shows a smooth non-textured print sheet. I also see the corners already pulling up. This is very typical of an alcohol wipe down. Try washing again, but this time no sponges, just use half a fresh paper towel to scrub with; use plenty of any plain dish detergent that is not "contains hand moisturizers" or similar. Use hot water for washing and rinse.  Rinse until water sheets off the bed, then use another fresh paper towel to dab up the few remaining drops. 

Also - at this point - please take a photo of the actual part being printed.  Maybe something else is going on, too.

Dish soaps to avoid: https://www.walgreens.com/q/dish+soap+with+moisturizers

Posted : 31/10/2020 7:52 pm
olinjt
(@olinjt)
Active Member
Topic starter answered:
RE: PLA Prusament color change change leads to blobs

For some reason, the other pics aren't gettin uploaded and they are not large...strange.  I didn't use alcohol, just soap and a paper towel as above.

Posted : 01/11/2020 7:19 pm
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