Notifications
Clear all

wrong layer adhesion  

  RSS
Milos V.
(@milos-v)
Prominent Member
wrong layer adhesion

Hello,
since the the printer build-up I have been printing something every day (it means for 3 days now). On the beginning, everything was just fine. Two days later I noticed, filament line is missing few times. It was not the complete layer, just small piece. On bigger prints it was once/twice per print, mostly cosmetical problem.
Today when I tried to print an object with thin wall (about 1mm), the layers sometimes lose adhesion, filament lines followed the nozzle, but did not remain on the object.
Everything was printed using original Prusa PLA, standard slic3r settings for MK2 z-hop, layer height 0.20 NORMAL or 0.15 OPTIMAL.
It seems the nozzle is not blocked, filament flows straight down.
First layer is always perfect, it starts to go bad several mm later.
Worst it was trying to print just a tube of 1mm width walls. After about 10 layers it lost adhesion, lines did not stay on the print.
I tried two different PLA colors, one was a little bit better, but maybe it was just an coincidence.
Bellow you can see the picture of filament filter object, the box lock was not finished correctly. Before this failure where the wall where thicker it was better, but some mistakes also happened.

And one more picture. Yellow parts where printed tomorrow, almost perfect. The white parts today from the same gcode but full of errors. I thought it is because of different filament, but after replacing back for the yellow one, it was also bad. These rings where printed as standalone and horizontally.

Any suggestions about what influences this behaviour, what to avoid, what to setup different way? What could go wrong in 3 days?
Thanks a lot.

Miloš.

Posted : 30/12/2016 11:41 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
Re: wrong layer adhesion

I had similar problems when the filament got loose on the drum, which lead to loops of filament crossing each other and effectively causing a knot, which then caused the extruder to under extrude...

It's good policy to keep the filament tight and tusk the end of the filament through a restraining hole in the side of the filament roll when it's not on the printer,

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 : 30/12/2016 11:51 pm
Milos V.
(@milos-v)
Prominent Member
Topic starter answered:
Re: wrong layer adhesion

I try to do so. I have two filaments, still nearly full. I hope not having loops on both of them. But maybe it underextrude for sime other reason. I also noticed that inserting filament goes worse then in the beginning. It does not catch it on the first time everytime.

Posted : 31/12/2016 12:22 am
Milos V.
(@milos-v)
Prominent Member
Topic starter answered:
Re: wrong layer adhesion

I tried to rewind the spool a little bit, at least to the point where it seemed to be original and tight again. I did not find any knots, however trying to print now and for an hour and half no mistake. So it seems this could be also my problem.
Thank you Joan for your hint, I would not guess this.
Do you use any special spool holder, or still the original from Prusa? It does not hold tight even during printing as the spoil moves.
MIloš.

Posted : 31/12/2016 4:15 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
Re: wrong layer adhesion

I use the standard roll holder, and a guide like this
http://www.thingiverse.com/thing:1787622

This guide is very close to the filament on some of my new reels, and it actually causes the filament to derail at the end of a print, when I raise the extruder to the top of the frame, (there is nothing to rewind the spare filament as the extruder rises after finishing printing....

I did try a filament guide with a smaller hole, but found that is caused the filament to bind when the extruder was to the left or right of the build plate.

best wishes, 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 : 01/01/2017 2:30 pm
Ancientwolf
(@ancientwolf)
Estimable Member
Re: wrong layer adhesion

In Slic3r, slice the part, and preview it- are those lines missing in the preview as well? Manifold errors will do that too.

Yeah, its that guy... 3D Nexus

Posted : 02/01/2017 5:24 am
Share: