VERY challenging "Gaps Between Infill and Outline" solving

[bastienb 12]

Hello everyone!

Introduction

I have an Ultimaker 2+ extended that has been running smoothly for 1500 hours. I mostly print the same STL file and never encountered any issue. And now I am stuck on the gaps between infill and outline...

I went here, here and I called the guy who sold me the printer whitout any solution...

Hardware (same one since the early prints of this printer and between my UM2+'s)

 

• Ultimaker 2+, 1500hours of printing
  
• PLA RepRap emotion tech 3mm, white, new roll, good quality
  
• Non official nozzle sold by a shop (Ideokub - Le Mans - France), 0.4mm
  
• Official glassplate, as new
  
• 3DLAC for plate adhesion, works perfectly
  

 

Problem

One day, the printer started printing like this. I did not changed the generated GCODE (cura 2) which is the same for months and which works well on the other printer.

What I have done (with no success)

 

• Leveled the bed
  
• Cleaned the glassplate
  
• Changed the nozzle
  
• Changed the PTFE tube (new official one)
  
• Dismounted and clean the extruder
  
• Used a new GCODE with big outline overlap and slower printing (first of the two pics, it made things worse actually)
  
• Tensioned the stepper motor belt
  
• Cleaned all the printer (plate, rods, axis)
  
• Put unilube on the rods and lithium grease on the Z screw
  

 

I am a bit desperate on this... if you could help me it would be very nice.

Thanks a lot!

Edited March 19, 2017 by Guest

[neotko 1,417]

Check if your machine x/y is square

http://www.thingiverse.com/thing:81415

 

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

The process is the same on um2 than umo+

Also. Does that happens near the area where the bowden curves more? Is the spool at almost the end? (That can increase the friction making fluctuations on the extrusion).

Anyhow probably someone else has more ideas.

Edit: Did you said Unilube on the rods???? You mean Only on the Z screw right?? All the other smooth shafts only require sewing machine oil.

Also, is the feeder clean?

How to disassemble the um2+ feeder

http://support.3dverkstan.se/article/64-disassembly-of-the-ultimaker-2-plus-feeder

Edited March 19, 2017 by Guest

[bastienb 12]

Ok there was some issue with the x/y squareness. It is corrected and I made a test, seems to work on the small part... I will launch a bigger part tonight and tell you how it went tomorrow!

For the other questions, yes, it tends to be worse at the bottom right of the glassplate.

How did you think of the squareness?

Thanks a lot!

(I will mark "best answer" when all the tests are OK, I became a bit paranoid with this machine...)

[neotko 1,417]

I been doing a very serious calibration on my 3 machines this past 3 weeks, that's why XD

Also please confirm you don't used lube on the smooth shafts, it will work for a time but as soon it dries and get dust it will add friction (that's why is only for the z screw of the z motor).

The bowden is more complex to fix, I think some users do change from pfa to ptfe bowden because is slightly more slippery. @ultiarjan on the old um2 feeder made a 'thing' that raised the feeder, don't know if there's something like that for the um2+

@gudo for example made a rotating thing that allows rotation freedom for the bowden, but I think is for um2 not plus

https://www.youmagine.com/designs/bondtech-feeder-rotating-bracket-um2-um2-extended

Maybe you can use gudo or ultiarjan design to change yours?

[bastienb 12]

Ok thank you! I am not sure if I am willing to embark making a huge modification... I thougt the printer would be capable of doing its job (but after 1500hours of printing it is getting very tricky). Maybe I will go for the ptfe bowden on the UM2+ which works properly and see how it goes.

I have just finished the test on the bigger part: problem NOT fixed unfortunately...

I confirm that I only lub the printer as it is officially advised (with the exact same products).

[neotko 1,417]

So the short belts are as tight as possible? Umm

And the x/y belts do they fell ok or a bit loose? Weirdly the ahort belts should be the ones that cause that.

If you print small circles they don't look right, right? Umm

[bastienb 12]

All the belts seem tight. And I can print small circles without any problem (you can see in the pics). But there are gaps between infill and outline...

Told you I was desperate

[neotko 1,417]

Can you check using a default profile to print something small (for speed). Maybe there's an option on the alicer that's affecting the print. And ofc you don't have any leak anywhere and the bowden is fully 'in' (sometimes hits the aluminum and fells in but isn't inside the coupler).

[bastienb 12]

Is there any object/shape that could be better for your diagnosis? I made sure the bowden is fully 'in' (had the problem before)

[neotko 1,417]

Just a 2x2x2cm cube with a 1cm hole should do.

Also juat in case all previous prints where with the same filament? (this is getting hard to debug )

[geert_2 557]

Could something like this be caused by a worn-out nozzle cooling fan? So it doesn't cool enough and filament gets heated too much upwards and gets stuck? Or by a worn-out feeder-wheel, so it doesn't bite enough? Or a combination of one of these, with filament near the end of the spool, so it is wound-up too strong? If you cleaned the nozzle, did you carefully (!) poke through it with a 0.39mm needle? If burnt residus would be accumulated, it might reduce the opening from 0.4mm to 0.3mm or so? (I have sand down a standard 0.5mm needle to 0.39mm and used that.) Or the nozzle touching the aluminum cooling plate, so it loses its heat? Have you tried a small test print with a "known good" filament?

I am just guessing and thinking aloud, since it appears you already did all logical things...

[bastienb 12]

@geert_2

- I checked the cooling fan and it is OK

- I cleaned and checked the feeder-wheel and it is OK

- The nozzle is new : )

- The filament I use is a well-known one

Thanks anyway, I think another thinking person is not a luxury! And better saying twice than missing

@neotko

- everything is using the same filament RepRap emotionTech 3mm PLA white

So I did your cube test. I tried with the natural PLA (same everything else) because the other roll was busy and it came perfectly out:

And I thought a bit and saw that the issue where localised on the plate. So I did the cube test everywhere on the plate:

Here with better pictures as "zoom":

You can see that the closer to the top right of the machine (sorry I did not rotate the pic) the worse it gets. So for me it is definitely the X/Y. An "ultimaker guy" from the shop (Ideokub) told me that the rods could be damaged and that I should change them. What do you think?

I will try to exchange X and Y and to turn the rods to see if I can get the problem to move on the plate.

Closer!!! Thanks again =)

[neotko 1,417]

Maybe the central x/y shafts are bend? Umm

To check the x4 8mm smooth shafts, if you look to the slider you should see if it goes up/down when it slides, that's how I did debug mines long ago before moving to misumi

Check the first gif of this post I made loooong ago

https://ultimaker.com/en/community/16964-umo-woobling-x-block-sometimes-y?page=last

For the thin 6mm central x/y shafts I don't know how to debug them.. Maybe @IrobertI has more ideas

[neotko 1,417]

Also I wonder if is just a bed level issue? I mean, is so concentrated on a corner. Maybe..

a) Maybe the screw is pushing up the bed glass? Remove the bed glass and check if the screw is touching the glass of if is 'below' the metal plate.

b) Maybe your bed glass is curved?

Ofc if the guy at the shop thinks is the shafts, maybe is that...

Check to rotate the glass 180degrees and that should show if is the glass, or the shaft?

[bastienb 12]

Sorry for the late answer but I am getting really upset by this problem... I tried the stuff you wrote without any success!

But I thought a bit and for me we are dealing with several problems, all mixed up and probably the "it works on my other UM2+" is not helping. So I made a reset regarding my debugging process. I consider all the things I have done as not done and start anew. Maybe a fresh look could help... Oh and I am thinking ONE thing at a time. I mean, making sure that thing is OK and works well before going anywhere else.

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Hello everyone!

I have a problem with my UM2+, my prints started to look like this :

Here is a picture during the print:

I printed literally hundred of these and everything was fine...

I tried to print 5 little cubes (2cmx2cm) with a 1cm hole in the middle and here what I got:

The other side of the plate:

The issue is not as bad as for my other prints, so I tried with smaller parts (4mm squares/circles and 2mm walls):

And here it is! I use a UM2+ extended with about 2000hours of printing already. 4mm nozzle, PLA green EmotionTech (RepRap), 3DLAC and I levelled the bed beforehand.

So, what should be the very first thing I should do? (thanks!)

[neotko 1,417]

My first thought would be to change the coupler and make sure that when installed is at the correct position without too much compression.

https://ultimaker.com/en/resources/22188-how-to-replace-the-tfm-coupler

Very important to use the spacer to don't compress the tfm coupler or it will do underextrusion because the tip can bend and make the inner area smaller and reduce its life span.

https://www.youmagine.com/designs/ultimaker-printhead-spacer

The 16.8 space distance is the key to install it right.

[bastienb 12]

I printed the spacer, checked it with a caliper, unmounted the head and I made sure it was properly spaced. You have the "proof" picture and the result.

[geert_2 557]

I think it is a good idea to restart from fresh, in case of hard to solve problems.

To me, this looks like underextrusion.

If the filament is rather hard, as in the case of PLA, and it is bent into a tight corner on the end of the spool, try to manually straighten it. This will give far less friction in the nozzle and coupler. I usually wind it in the opposite direction around a skater wheel of 7cm diameter.

Also, I would try the following things: First remove filament and do an atomic pull to clean the path. Then manually insert a piece of filament (with cold nozzle) to see if it slides smooth through the nozzle and teflon coupler? Then insert the bowden tube, and manually slide a longer piece of filament from the back of the printer through the whole path bowden-tube, coupler, nozzle (with cold nozzle). Is this going smoothly without friction?

Then heat the nozzle, and manually feed a bit of filament through. Does it come out smoothly without too much friction?

Then start a small print (e.g. a cube of 10mm x 10mm x 10mm), and manually feed the filament while printing.

If you would have a similar printer available, you could try the exact same things there, to compare.

If all this goes well, then at least you have an indication that that part of the printer is reasonably okay.

[Torgeir 242]

Hi bastienb,

Most of your problem is in the inner part of the build plate, true?

If you print with high flow demand, as fast as you can, you may see some sort of under extrusion on object made on the "Northern" side (inner side) of the heat bed. This is the sign of close to the max flow for that nozzle size. However, this might occur at an earlier stage if some parts do not function properly. This might be the tfm-coupler (as Neotko suggested), even if the distance is right the compression might been a little to high from the beginning, so the dimension passage is shrink-en gradually over time. This increase the pressure on the bowden tube, on top of all this the track line (from the knurled wheel) is on the outer part of the inside of the bowden tube, so here the friction increase the drag forces making the situation worse. Actually, this is why the problems is first visible on the “Norther” placed objects. So this is the reason for pressure difference (variable extrusion) that will occur all over the heat bed when things go wrong.

Since you've already changed the bowden tube, Neotko's advice is next..

Thanks.

Torgeir.

[bastienb 12]

@geert_2

- I installed the following thing:

Without any improvement... (at all, not a slight change)

- For the atomic, here the result:

I think it means it is quite clean! I do not see any anomaly, maybe a very tiny bubble or air at the very end... but that's it (the nozzle and the PTFE couplers are new and bought in the Ideokub shop).

- I took a bit of PLA, smothed the end to avoid any disturbance and I put it as you said. It goes well, hard to tell about "smooth" but I do not feel anything in particular, not a scratch or smg with which I would have to push hard.

- Same thing with the bowden tube

- When I select "move filament" and turn the wheel, it comes out normally (I think, I do not remember what "normally" is, but it comes out regularly)

- It was too hard to push the filament by myself for the print, I under-extruded. So I let the clamp thing loose and it come out normally. And the result was the same, only the top-right print was wrong.

Thanks for your help...

@Torgeir

So if I understand correctly, the printer is at the edged of messing all the prints, but as the top right corner is the toughest, I can see it here first?

**EDIT

I have just made another print to be sure nothing changed... The problem is now worse on the top left of the printer. And the glass plate has been turned 180° (by error).

[Torgeir 242]

Hi bastienb,

When I look at the "atomic pull", I'll think you have some serious error in your setup..

It looks like your "replacement" nozzle is 1.75 mm? As we see the filament size 2.85 versus the tip size I'll believe is 1.75 mm, this restrict the flow and increase the pressure inside the bowden tube. Check the nozzle on the printer and compare the inlet side of the nozzle you're using.

Thanks.

Torgeir.

Torgeir.

[Torgeir 242]

Hi bastienb,

When I look at the "atomic pull", I'll think you have some serious error in your setup..

It looks like your "replacement" nozzle is 1.75 mm? As we see the filament size 2.85 versus the tip size I'll believe is 1.75 mm, this restrict the flow and increase the pressure inside the bowden tube. Check the nozzle on the printer and compare the inlet side of the nozzle you're using.

Edit: The filament should be the same diameter all the way to the tip..

Thanks.

Torgeir.

Torgeir.

 

[neotko 1,417]

Hi bastienb,

When I look at the "atomic pull", I'll think you have some serious error in your setup..

It looks like your "replacement" nozzle is 1.75 mm? As we see the filament size 2.85 versus the tip size I'll believe is 1.75 mm, this restrict the flow and increase the pressure inside the bowden tube. Check the nozzle on the printer and compare the inlet side of the nozzle you're using.

Thanks.

Torgeir.

Torgeir.

 

That's exactly what I was gonna write. Looks like a 1.75 nozzle

[neotko 1,417]

Caliper that, if is 2mm then your nozzle is for 1.75mm. It should be around 3.1x - 3.2mm (the standard size for 2.85mm)

[geert_2 557]

This is what I would rather expect from an atomic pull: see the nice orange one at the bottom. It has still a little bit of white, since I was changing colors from orange to white and back. This is from an UM2 (non-plus) with standard 0.4mm nozzle, 2.85mm filament. On an UM2+ with removable nozzle you might see some additional lines, but the general shape should be similar:

Edited March 24, 2017 by Guest