Adhesion issues  

  RSS
marchvet
(@marchvet)
Active Member
Hi,
 
I have had the following problem with my MK3s since I got it a few months ago.  Please see below:
 
Firmware:  3.9.1-3518
Sheets:  PEI and Textured
 
NOTE:  The printer is in its stock configuration since receiving it fully built from the factory.  No modifications have been made.
 
Problem:
When trying to print multiple items over the entire sheet, after about an hour the prints will start to lift, which causes them to stick to the nozzle.
 
Things I have tried to resolve it:
  1.  Clean PEI and textured sheets with soap water and always keep them clean in between each printing session.
  2. Tried different filaments(TPU/PLA), temperature settings, speed etc.
  3. The Z height is stock on PLA from the factory and the textured is on a separate profile.
  4. Lowered Z height yesterday a little further on the textured profile and still got the same problem.
  5. Arranging the pieces on the sheet different ways.
The Z height for each is as follows:
PLA:  0.440 - PEI sheet
TPU: 0.770 - Textured
 
However,
 
IF I print 1 or 2 pieces, I have no problems at all.
 
What can I do to try and resolve this issue?
Posted : 12/01/2021 4:48 pm
Diem
 Diem
(@diem)
Reputable Member

This does read like a first layer/adhesion problem.  If you're sure about the cleanliness of the bed post a photo showing the first layer & bottom of your printing attempts.

Cheerio,

Posted : 12/01/2021 5:28 pm
marchvet
(@marchvet)
Active Member

@diem

Posted : 12/01/2021 10:28 pm
marchvet
(@marchvet)
Active Member

Note = It doesn't start to lift off the bed until about an hour into the print.  

Posted : 12/01/2021 10:29 pm
Diem
 Diem
(@diem)
Reputable Member

OK, you have an adhesion problem.  Your first layer Z is pretty close; it might benefit from very light tweaking but it's not your major issue.

First clean again with soap and HOT water.  Keep your fingers off the plate surface.

Printer Setting:

If you have not done so switch your printer to 7x7 mesh bed levelling. 

For some awkwardly shaped prints it can pay to reduce the print speed by 10% - 20%

Slicer:

For this print try setting Elephant foot compensation to zero in Print Settings, Advanced.

It doesn't start to lift off the bed until about an hour into the print.

That's typical with poor adhesion, it doesn't have much effect until there is enough height for leverage to play.

You have some visible warping, is your workshop particularly cold or drafty?  If so a few degrees warmer print bed might help but shut the door first.  You could try a 'temporary enclosure' - AKA a large cardboard box, placed over the whole printer, to see if a permanent enclosure would be worthwhile.

Hth. Cheerio,

Posted : 13/01/2021 2:44 am
octal liked
3DK
 3DK
(@3dk)
Eminent Member

Hi marchvet, You’ve posted your note in the Prusa Mini forum. You may get further advice if you ask in the MK3 forum. Fingers crossed you find a solution. 

Posted : 13/01/2021 9:49 am
marchvet
(@marchvet)
Active Member

@3dk

I originally posted from my phone.  Sorry about that. Is there anyway to move this to the right forum?

Posted : 13/01/2021 7:30 pm
JoanTabb
(@joantabb)
Moderator

@marchvet

You could try asking one of the moderators in a PM...    (Once you can send PM's Lol) 

I have moved it for you. 

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 : 13/01/2021 9:14 pm
JoanTabb
(@joantabb)
Moderator

use 7x7 Mesh Bed Levelling,  Wash the build plate well,  rinse well and dry immediately with plain paper towels,  Instead of the Prusa First layer calibration setting, use  something like 'Life Adjust Z My Way' 
https://forum.prusaprinters.org/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/
for PLA, try a bed temperature of 70C 
If using a Brim, make sure that elephants foot compensation is turned off, so that the Model adheres to the Brim properly. 

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 : 13/01/2021 9:36 pm
marchvet
(@marchvet)
Active Member

@joantabb

Thank you.  So with the elephants foot option, should I leave it on if I am not using a brim?  

Also, I am printing TPU on the textured sheet.  

A few users have suggested I slow down my print speed, but is the "max print speed" the overall print speed? 

Posted : 13/01/2021 9:44 pm
Peter M
(@peter-m)
Prominent Member

Elephants foot option, if you use a brim attach to model , disable this.

Printing on a powder coated sheet, I go a little lower then an a pei sheet, then the holes on the powder coated sheet will fill in.

Your z layer, if you are confused  , try a little higher, then go in little steps lower.

Pei sheet, if you go to low(a little), and it could still look perfect, then further in the print it could come loose(or warp).

 

Posted : 14/01/2021 4:48 am
Peter M
(@peter-m)
Prominent Member

Extra and normally not needed:

print first layer slower,

Bed 10 hotter for whole print,

print first layer hotter(extruder).

Use glue stick.

Use a draft shield around the model, to keep wind away, keep it hotter.

use a big box around the printer to keep wind away.

let printer heat up before printing.

Posted : 14/01/2021 4:53 am
Share:

Please Login or Register