Top Layers not touching - UM2

[00D00B 58]

I'm following this topic from a while now because I've got the same problem on 2 of my Ultimaker 2 :(

I did try a loot of stuff by now... Cheked belts, pulley, extruder, everything ! I even changed the hotend, the back pulley (200 2GT 6.5), the LM6LUU linear bearings, and the temp sensor.

I'm maybe on something intresting today by changing a new part which is the filament drive gear. In fact, i saw that it seems to be a little bit tired and the teeth were less sharp.

By now it works, I'm gonna start the famous calibration cube everyone tried here to make sure it solved the problem and will come back to show you (:

[Nicolinux 288]

Ok, I tested further. First I noticed that the first layer looks kinda overextruded. Didn't see this in a long time maybe due to the ever present under extrusion.

Then I started taking ferrite cores off to see if it influences the problem:

Now I am back to only one ferrite core for the feeder motor.

I think it was to early to call it solved, but this is one of the most best leads so far because it did influence the print quality greatly.

@Dim3nsioneer I have printed one square with the latest Cura beta with a concentric pattern (this is not infill).

[00D00B 58]

Nico I will send you a gcode tomorrow that you should test. If it doesn't work on your machine then I think my solution seems to be the one (or at least for me). If it's ok for you too, We'll continue to experiment...

I've launched a 7h print, we'll see how's going !

[esteban-pacheco 33]

so,e one did managed to figure this issues out? is there a real solution? im tired of doing tests...

[Nicolinux 288]

@esteban-pacheco Well it did improve thing greatly and adding a ferrite core is very easy and quick. It won't hurt so I'd say - try it.

[Dim3nsioneer 557]

That's really good news. If the ferrite core really solves that problem, then there must be some really heavy pickup resulting in wrong step numbers.

However, the test with the concentric infill shows that it is a problem of the stepper motor and the e-coordinate respectively. Linear infill and concentric infill strongly differ in the acceleration situation (with linear, motion comes to a stop at each line end, well, almost - while with concentric infill motion is limited by the x-y-jerk). So far, everything looks consistent.

[DidierKlein 729]

@nicolux, did you change the position of your knurled bolt? Mine is close to the edge of the motor axle

So it would all be down to noise? I'm wondering what other consequences this noise has on the other motors.

I there a way to isolate the noise in another way?

Why doesn't this appear on the UMO ? (or does it?)

[Nicolinux 288]

Ok, what's next? I will measure the extrusion again but this time with the nozzle attached (like Robert suggested). But other than that. Swap boards?

Edited October 21, 2015 by Guest

[Nicolinux 288]

 

@DidierKlein I didn't touch the knurled bolt. It does fit well and grips the filament fully.

[esteban-pacheco 33]

@esteban-pacheco Well it did improve thing greatly and adding a ferrite core is very easy and quick. It won't hurt so I'd say - try it.

 

does it make a difference?

what kind of ferrite core are you using? i mean, the DIAMETER (3.5 mm or 5.00mm)

cheers...

[Nicolinux 288]

The diameter is around 5mm. I wouldn't get a thinner one because you'd have a hard time fitting the motor cables in there.

[gornnr 2]

As an interesting possible test. I measured the extrusion from extruding into free air (while doing an Atomic Cleaning) and it measured 0.43mm.

Thought being, should there be a small clog the extruded diameter will be reduced due to the restriction.

[ultiarjan 1,223]

I was sceptical about the ferrite core idea, but today I received one in the mail from @Nicolinux   ( thanks! ) so I did a few tests;

I placed the core on the cables about 5 cm from the feeder motor, would that be a good position? Basic settings used: 205c/60c, colorfabb fluorescent green, almost new, just opened 1 week ago, production date june 2015, 100% fan, 100% flow, olsson block + 0.4 jet nozzle

first the test cube without the ferrite core;

and now with the ferrite core;

and without the ferrite core, at 106% flow;

and with the ferrite core, at 106% flow;

If you ask me the results with the ferrite core are slightly worse .....

Here's a picture of a similar sized object, printed in the first week when this machine was brand new, no idea about the settings at hte time, but the top is very good...

My gut feeling still says this issue is mechanical...  when I feel like it tomorrow I'll give the machine a good cleaning and oiling and try again.

Edited October 31, 2015 by Guest

[neotko 1,417]

For long use machines I would check the belts. I have zero idea but if the spring inside the black sideblocks are anything like the chinaclone verdion I bough, then the springs have very little force and they only help fill the gap of the litte big longer than needed belts. I know that on um2 if you take the screws it would self adjust to keep the belt tight, but after toying with one un-assembled um2 side block I don't think that the spring should last more than a year doing the correct tension. Ofc I played with a clone.

For me the ferrite worked but this week took it out and I don't have the problem, IF I keep the feeder cable warped (on a cable warp) and on a side away from the cable stream.

I have now an oscilloscope but little time to run some tests, maybe in a pair of weeks I will record the feeder for electrical noise.

Edited November 1, 2015 by Guest

[3dnerd 6]

Hi,

nicolinux asked me as well if I want to get a ferrit core (@Nicolinox: thanks).

I answered him that I want to be sure if I face exactly the same problem and therefore I did a testprint (Innofil PLA Yellow) with the 20mm cube at 215°. Here are the results:

Last bottom layer 1:

Last bottom layer 2:

Top layer:

(Forget the blob on the image 'top layer', it happened because I did a long pause to take the bottom images. A big string of filament was coming out of the paused nozzle and I forgot to swipe it away on resuming the print)

As you can see the result is not the best.

Then I tweaked the settings (on the UM2 LCD panel) to:

- Temperature: 220°

- Flow 110%

- Speed 90%

and got:

last bottom layer:

Top layer:

With these setting I think the result is almost perfect.

What do you think?

Edited November 1, 2015 by Guest

[Nicolinux 288]

Thanks for testing guys. Even if the test fails, it still helps to narrow down the issue.

@ultiarjan: Could you please move the ferrite core upwards so it touches the stepper? On my printer there seems to make a difference.

[ultiarjan 1,223]

Thanks for testing guys. Even if the test fails, it still helps to narrow down the issue.

@ultiarjan: Could you please move the ferrite core upwards so it touches the stepper? On my printer there seems to make a difference.

 

Sure. Will try somewhere coming week.

[Schoffra 1]

Hi guys. I followed this thread for quite some time now. I also have the problem of bad looking top layers (lines not touching). With the extrusion testprint I reach 10mm3/s with no problem at all. So underextrusion does not seem to be the problem. I startet to increase material flow to 110% an I get pretty nice results. Is there any way to set the material flow in cura or do i have to set this manually every time anew?

[neotko 1,417]

Hi guys. I followed this thread for quite some time now. I also have the problem of bad looking top layers (lines not touching). With the extrusion testprint I reach 10mm3/s with no problem at all. So underextrusion does not seem to be the problem. I startet to increase material flow to 110% an I get pretty nice results. Is there any way to set the material flow in cura or do i have to set this manually every time anew?

 

I don't remember on cura but to do the machine flow change by gcode it's M221 T0 S100 , where S100 its 100% so M221 T0 S110

The T0 its tool 0 so it changes the flow of the main extruder.

[Labern 774]

Just edit and save all your material profiles on the machine to have 110% flow.

[JohnK 30]

I have now began to have this problem, all was working fine before and like others, walls print fine, no underextrusion / no filament slipping.

I actually first started noticing it while using a 0.8mm nozzle (Olsson block). It is happening with all nozzle sizes, fairly consistently.

Things I've tried to remedy the problem...

- Cleaned and re oiled the axis

- Was using Roberts feeder, tried the standard feeder, no difference (apart from making life more difficult)

-Tightened the short belts as much as I could

- Tried different filament brands / colours

When I get a chance, I will post some pictures.

One thing I have noticed (could be my imagination), when pushing filament through, even by hand, the extruded material doesn't seem as thick / swelled as it used to. The nozzles I'm using are clean. Could room temperature play a part ?

[Schoffra 1]

Thank you all for the replies. First I was very unhappy to tinker with material flow but the results are so nice that I can completely live with it. I have the check if the dimensions of the print are still within parameters. I will print some test cubes to check on that.

[Labeeb 0]

Hello Everyone,

I am experiencing the exact same top fill issue with my Ultimaker 2. Lines on top surfaces are not closing/touching perfectly. I can see a significant gap between lines on top (solid)[/media-thumb][/media-thumb]

I have followed everything from the following link but unfortunately there has been no improvement so far:

http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#underextrusion

- I have used Ultimaker Ultimate blue PLA, Colorfabb Shining Silver PLA/PHA, and Faberdashery Village Green PLA

- 0.2mm layer height and default Cura settings

- I have tried Cura 14.09, 14.12.1 and 15.02.1 but to no avail.

- Tried 0.6, 0.8 and 1 mm Bottom/Top thickness

- Factory reset

- Tried different firmware versions

- I have tried UltiGCode and Marlin/Sprinter GCode Flavours but the results are similar

- The side walls look very nice (no under-extrusion)

I can see that several people have been facing the same issue, could anyone who has resolved the issue please help me here?

Thank you guys for any help.

[Labeeb 0]

If anyone from Ultimaker could please help with this issue I'd be immensely grateful and I think many others as well.

Nothing that I have tried so far seems to improve the gap in between the lines on top surfaces.

I have now also tried:

- Formfutura Black PLA

- new PTFE

- ferrite core

- latest release of Cura 2.1

I have lubricated all rods, aligned the gantry and tightened belts and pulleys (I have always maintained my UM2 well).

I have run the cylinder test and attached the picture.

Please do not ignore my question. I use my UM2 for work it's not just a hobby. Please reply something even if it's just to say that you don't know.

Edited April 22, 2016 by Guest

[SandervG 1,521]

It is not equally clear with all the colors but the green one seems to show a pattern.

This could be a sign that one of your axis are bend. Have you done a lot of Atomic Methods for example where your print head was not positioned in the corner?