Layers do not stick with adjacent layers

[Yuviten 0]

Hi ,

I am Yuviten. I am a new bee in to 3d printing. Glass adhesion is good. But i find the outermost layer of my print peeling off. The shell alone doesnt stick well, to its adjacent next layer. where as the infill is fine. any thoughts??

[gr5 2,002]

What material are you printing? I'm guessing ABS.

Try using no fan at all. Set fan to 0% for the next part you print. also cover your machine enough such that the air temperature reaches 35C to 40C (but no hotter than 40C). These 2 things will help with your issue.

If you are printing PLA then you probably have underextrusion - try printing a little hotter and slower. Please show a photo of what you are talking about as your description may seem very exacting but there are 2 completely different phenomenon that you could be describing.

[Yuviten 0]

Hi,  Thanks for the quick reply,.  I am using PLA.  

[Yuviten 0]

[dodgrr 27]

try turning the temp up and slowing down the print speed a bit, looks like the material isn't staying hot enough to bond.

[gr5 2,002]

I think it's underextruding. Wait - is that only the bottom layer that is separating or all layers? If only bottom layer then you need to raise the bed a little closer to nozzle - just rotate the 3 leveling screws - do not bother with the leveling procedure again.

if that's happening on every layer then google "ultimaker underextrusion gr5" and look for a post where I list at least 5 potential causes. But slowing down print by 2X and raising temp by 10C is good advice.

[cloakfiend 992]

I still get that from time to time and never really figured out the cause.

[danilius 118]

It looks like the shells are peeling off. Too low temp and underextrusion (usually both at the same time) are generally the cause.

The simplest solution is to increase the temp, of course, and the material flow as well.

[cloakfiend 992]

The material flow didnt work for me. Must be a very slightly blocked nozzle then. And too low temps.

[Yuviten 0]

Thanks everyone!. I will try with increased temp(now 240 for pla), slow speed(now its 40). also does humidity play a role in this cases?. I heard the Rh value should be 40 to 45 per.

[danilius 118]

I am still in two minds about the effects of moisture in the plastic itself. Plastic does absorb moisture (nylon is aggressively hydrophilic) and currently I keep all my plastic in sealed bags with silica beads. I have seen them change from amber (dry) to deep green (saturated) but have not had the time to conduct empirical tests. Currently I have not come to any conclusion on the subject because of the sheer amount of variables involved. Ideally I should buy some new nozzles, clean out the olsson block thoroughly and print saturated and unsaturated filament in some kind of test, although what that would consist of (essentially a shape in which we can easily determine the effects of moisture) is anyone guess.

Suggestions?

[Yuviten 0]

10X10X10 block with shell thickness 2mm(In pic). where as 0.8mm shell thickness was very good.

[cloakfiend 992]

Stick to divisions of 0.4 unless you are using a different that stock nozzle. I print EVERYTHING with shell 1.2 and have no problems. I always had occasional shell issues with 0.8 shell, but i guess it depends on the model.

If your going for 2mm go 1.6.

Edited October 26, 2015 by Guest

[Yuviten 0]

So issue is with shell thickness. Now i am sticking with 0.8 and 1.2. Will try it and give feedback. Thanks everyone for your timely reply.

[danilius 118]

Your shell thickness should be a multiple of your nozzle. Assuming you have a stock UM, then you can have a shell thickness of 0.4, 0.8, 1.2, 1.6, 2.0 etc. and they should all work fine, except for the 0.4 which is just asking for trouble.

[gr5 2,002]

Okay - the problem is not underextrusion.

The problem seems to be that infill is not reaching the shell. This is caused by backlash or play usually (two words for the same thing). Is this a UMO or UM2? The UMO gets backlash more often. Backlash is most often caused by either loose belts (most often the short belts to the motors) or by too much friction. Test for friction by pushing the head around. You should be able to push the head on UMO or UM2 with one finger on each block opposite the head. If friction is too high on the UMO then it's usually the end caps. Hell just tell us which printer you have and if it seems the belts mighth be loose or too much friction. Tight belts can cause backlash due to creating high friction also. Which printer do you have?

[gr5 2,002]

Oh - don't go over 240C with PLA. That's asking for trouble. Consider 240C to be the max temp and only when printing really fast.

[Yuviten 0]

its UMO.  and shell thickness 1.2 gives me this result.  Giving compression force on two side shows the problem, where as by seeing with bare eyes it is not visible

Edited October 27, 2015 by Guest

[Yuviten 0]

Previously i used 1.2 shell thick with 15per infill overlap. In This photo i used 1.2 shell thick and infill overlap 50 per. Looks good. when looked closely there is outer layer, inner layer and infill. Infill and inner layers stick where as outer layer and inner layer doesn't stick . thoughts?

[Yuviten 0]

Any solution.. ?

[SandervG 1,518]

Okay - the problem is not underextrusion.

The problem seems to be that infill is not reaching the shell.  This is caused by backlash or play usually (two words for the same thing).  Is this a UMO or UM2?  The UMO gets backlash more often.  Backlash is most often caused by either loose belts (most often the short belts to the motors) or by too much friction.  Test for friction by pushing the head around.  You should be able to push the head on UMO or UM2 with one finger on each block opposite the head.  If friction is too high on the UMO then it's usually the end caps.  Hell just tell us which printer you have and if it seems the belts mighth be loose or too much friction.  Tight belts can cause backlash due to creating high friction also.  Which printer do you have?

 

@Yuviten, have you tried this?

Summary: tighten the short belts and make sure the end caps do not cause friction on the rods.

[Yuviten 0]

Yes.!. i tightened the short belts. and the end caps are fine too.  

Also i changed e steps per mm to 100 from zero.` Small parts are good. but large parts are not good. same problem. Outer layer peels off . Also there is ticking sound from motor. When i touch the filament, i can sense the motor skips,it pushes back the filament and hence gaps inbetween outer shell.

Edited October 28, 2015 by Guest

[gr5 2,002]

Isn't that part supposed to be square? It looks strange shape. how can you say it "looks good" if it isn't even square?

I'm still confused if your problem is underextrusion or play. If underextrusion try printing slower - half speed. But assuming problem is play - it can either be loose belts (CHECK ALL 6 BELTS NOT JUST 4 LONG BELTS) - usually the short ones to the motors - or it can be too much friction. Did you test friction? You should be able to push head around with two fingers one on each side block. What is this test result?

I wouldn't worry about "tick" sound - that's usually harmless and can have many causes - one is that the long belts don't line up with the rods and the belt goes up the pulley side and then falls back into the groove. There are other "tick" sounds - none of them that I know about are serious. Maybe make a 10 second video of the sound - but I don't think it's serious.

[gr5 2,002]

Also i changed e steps per mm to 100 from zero.

 

What? z steps? or e steps? esteps/mm on UMO I think should be about 830 to 840.

 

 When i touch the filament, i can sense the motor skips,it pushes back the filament and hence gaps inbetween outer shell.

 

What? Extruder skips back? this sounds like UM2! That shouldn't happen on UMO I think. Maybe UMO+ does that? If that is true then print at half speed. Or 1/4 speed. Until this problem goes away.

[Yuviten 0]

as i mentioned in previous post.  with bare eyes the gaps are not visible.  Just when you apply a little amount of force(compression) in bulges. like strings. a good fused 3d print will deform but not in this way (as shown in pic).  

 

Isn't that part supposed to be square?  It looks strange shape.  how can you say it "looks good" if it isn't even square?

I'm still confused if your problem is underextrusion or play.  If underextrusion try printing slower - half speed.  But assuming problem is play - it can either be loose belts (CHECK ALL 6 BELTS NOT JUST 4 LONG BELTS) - usually the short ones to the motors - or it can be too much friction.  Did you test friction?  You should be able to push head around with two fingers one on each side block.  What is this test result?

I wouldn't worry about "tick" sound - that's usually harmless and can have many causes - one is that the long belts don't line up with the rods and the belt goes up the pulley side and then falls back into the groove.  There are other "tick" sounds - none of them that I know about are serious.  Maybe make a 10 second video of the sound - but I don't think it's serious.

 

Edited October 29, 2015 by Guest