Irregular , "granular" extrusion

[oddoutput 7]

Hey,

I've had this one problem before, and it's where prints get ugly because of irregular layers.

When cleaning the nozzle I notice that the materials seems to sort of pile onto each other right outside the nozzle, causing the material to get thicker and rough.

My cold pulls are clean though and there's no difference between 210C and 190C

[eldrick 65]

Have you measured the filament diameter? I had similar results yesterday with some filament that was up in the 2.9+mm size. It causes variable friction in the mechanism.

[oddoutput 7]

The diameter of the material is 2,9mm so i would think that isn't the problem.

Next to that, I also had a roll of blue from the same brand which worked perfectly, untill now where it gave the same problem.

I switched to yellow to see if there was any difference but alas.

[niyoki 21]

did you also tried 220 degree for PLA. But I can see on your photos nozzle is too far from print bed.

good luck

[yellowshark 153]

It could be your filament, cheaper filament is made by cheaper equipment and cheaper processes and of course in China by cheaper people. Cheap means poorer performance and irregular diameters which will clog your feed system and reduce flow. Take your digital micrometer and measure along the filament for the length you need for the print and ensure as a maximum it is not exceeding 3.0mm. If it hits 3.0mm then it is not good filament by the way if it is meant to be 2.90. Two of the biggest suppliers ColorFabb and Faberdashery manufacture at 2.85 and every time I have measured it it has been within a tolerance of +/- 0.05mm.

If you do not have a micrometer then you ought to get one.

[oddoutput 7]

did you also tried 220 degree for PLA. But I can see on your photos nozzle is too far from print bed.

good luck

 

Why i try doing the atomic method I of course push the material through first at 230C. The material pictures i posted are from that.

I'm also not really sure how you can see from those pictures that my nozzle is too far from the print bed.

[niyoki 21]

I can see this because of the layer differences from bottom to the top. At the Moment I print with Innofil PLA at 220 degree. When I try to print with 210 degree same granular effect Comes out.

good luck

Edited January 11, 2016 by Guest

[oddoutput 7]

I can see this because of the layer differences from bottom to the top. At the Moment I print with Innofil PLA at 220 degree. When I try to print with 210 degree same granular effect Comes out.

good luck

 

I can pretty confidently tell you that the bed leveling is not the problem, as that would only affect the first layer(s)

As I said, the filament comes out like that at 195, 200, 210 and 230 so 220 will more than likely not make any difference.

I've measured the filament and it's between 2,8mm and 2,95mm.

Besides that, I've been printing pretty well with this roll of filament untill now.

Is it possible that filament gets stuck to the i2k insulator?

(I forgot to mention, I have a i2k insulator and a TFT coupler, both from 3DSolex.

[niyoki 21]

Today I saw from @gr8 very interesting topic. About bowden tube you can read there something interesting. I believed too long bed leveling has only with first layer to do, but I changed mine mind. Now I'm more happy wity my prints. I wait until first layer squished nice then let  my printer go. If it isnt I stop, clean bed then start again to printing. Link to gr8's topic https://ultimaker.com/en/community/18970-us-buyers-i-found-a-good-cheap-bowden-tube-replacement?page=1&sort=#reply-130535

kind regards

Edited January 11, 2016 by Guest

[gr5 2,268]

@oddoutput I think you have inconsistent Z movement. When the bed doesn't move down enough you get slight overextrusion and the layer sticks out a bit. This is less obvious with .1mm layering but this looks more like .05mm layer height.

You could try a bunch of things - clean the Z bearings, push up and down on the bed feeling for friction (with power off). You could add a heavy weight to the bed to see if it looks more consistent - around 1kg. Here is much more info:

https://ultimaker.com/en/community/11123-z-axis-layer-error?page=unread#reply-129204

[oddoutput 7]

@oddoutput I think you have inconsistent Z movement.  When the bed doesn't move down enough you get slight overextrusion and the layer sticks out a bit.  This is less obvious with .1mm layering but this looks more like .05mm layer height.

You could try a bunch of things - clean the Z bearings, push up and down on the bed feeling for friction (with power off).  You could add a heavy weight to the bed to see if it looks more consistent - around 1kg.  Here is much more info:

https://ultimaker.com/en/community/11123-z-axis-layer-error?page=unread#reply-129204

 

These are 0,2mm layers actually.

I doubt it's the Z movement because the filament already exits the nozzle all ugly, but i'll check it anyways.

[gr5 2,268]

Well you see how some layers stick out? If you think of each layer as a ring - some rings have a larger diameter. This is because it is squirting out more plastic than there is space to put it.

It can be that the extruder is working at double speed for one complete layer - either because temperature is much higher (if temp is higher the plastic is less viscous - more like water than tooth paste and so pressure is higher and extruder moves more filament) or filament diamter is variable (but it would have to vary hugely - like 50% change in diameter).

Much more likely the Z axis didn't move far enough so there was less space for the filament to go so it squirted out around the sides.

This is a VERY COMMON problem. It has many causes including having the bed rub the spool holder (check it out - there's not much space back there) and issues with the bed rubbing something else, or the Z screw having too much play combined with too much friction in the Z bearings. Some people end up getting all new Z parts including the motor, the screw and the rods and the bearings. Others have done some simple fixes like loosening and retightening the Z motor mounting screws.

[oddoutput 7]

I've tried loosening and retightening the Z motor mounting screw and I cleaned the feeder and it worked normally again for a small time.

Now the problems are that I can run one print before it stops working again (material being ground up in the feeder somehow when it print is already done and good?).

I've tried cold pulls again but each time the material just gets stuck or I need to leave the nozzle hot enough to pull it out more like a string.

And now I've tried installing my Olsson block again and I get the problem that the bottom and top layers don't touch (plus the whole "clogged" after one print thing.)

I checked the nozzle after another attempted cold pull and the nozzle was clean, except for a little bit of material still on the wall but that couldn't have been a problem.

Filament is the right size, nozzle is clean, I use an i2k insulator if that matters.

I'm really just getting more problems whenever one gets solved :(