Why does my print have tiny zebra stripes?

[cloakfiend 996]

When you say 'old' do you mean the fixed UM .4 mm nozzle, rather than the larger OB.

Have people done any actual detail tests regarding this? I've not seen any?

Printing large objects makes no real difference, but how about smaller more detailed stuff? does the larger OB block size have any influence over the quality of smaller more intricate prints?

I'm actually fairly happy with the OB to tell the truth, but this has always been in the back of my head. For people who regularly need to swap out nozzles its not an option, but for those who don't, It could be a factor. When I first saw a UMO i was actually surprised to see how huge the nozzle block was. Is there any chance of a slimmed down OB if it is an issue?

...and @drR1pper regarding the roll, anytime you print with wound filament on the roll there is tension pulling it to unwind, regardless of bearings or whatever as its would against itself. printing off the roll is the only way of truly eliminating any jams or snags that will ALWAYS be a possibility on the roll. I've talked about this often in many threads. It was more of an issue with the old feeder, but snags apply to any method. if you even get a slight snag and momentary gap in the feeding area, it will create a visible line on the surface of your print. It may be fine or subtle but it will be there, I simply don't want that risk, especially with 52 Hr long prints.

If you unwind something there is tension, if you don't there isn't, its that simple, the only issue is the amount of filament you use as its weight comes into play, but is negligible for smaller amounts.

Edited June 9, 2016 by Guest

[Torgeir 267]

When you say 'old' do you mean the fixed UM .4 mm nozzle, rather than the larger OB.

Have people done any actual detail tests regarding this? I've not seen any?

Printing large objects makes no real difference, but how about smaller more detailed stuff? does the larger OB block size have any influence over the quality of smaller more intricate prints?

I'm actually fairly happy with the OB to tell the truth, but this has always been in the back of my head. For people who regularly need to swap out nozzles its not an option, but for those who don't, It could be a factor. When I first saw a UMO i was actually surprised to see how huge the nozzle block was. Is there any chance of a slimmed down OB if it is an issue?

 

Hi cloackfiend,

Yes, the standard originally delivered with UM2.

I've read it in here some place: A very good place to use for testing purposes.

http://www.3dbenchy.com

The OB will be my next to learn and test out, as the 0.25 that will be very interesting.

I'll think this is a game changer... So when the budget allows... Yes!

A slimmer OB, not for me to answer. But if you like 0.8, -it might have to be of that size in order to cope with the need of heath capacity and at least a 40w heath element.

Thanks.

Torgeir.

[DrR1pper 4]

@cloakfiend

Hmm. Do you think that could be the cause of my issue?

[Labern 775]

There has been comparisons between the two blocks not long after the first releases. The OB had a bit more oozing but you can print at faster speeds. Also it can depend on what change out nozzles you are using as over time both E3d and 3d solex have changed the internal profiles.

There will be a more advanced OB coming out and nozzles in the near future.

[cloakfiend 996]

thats great news about the ob, will it come with any 'advanced' nozzles

...im assuming so, ill have something to look forward to!

Edited June 9, 2016 by Guest

[Torgeir 267]

@Torgeir

Thanks for the suggestion but i already tried printing it's longest length along the printers x and y axis and it made no difference in the outcome which only strengthens the theory that it could be a z-axis issue somehow/someway.

Thank you for offering to print it for me too. Here is the g-code i used and the stl.

g-code: http://www.filedropper.com/drr1pperprintsurfacetestpla'>http://www.filedropper.com/drr1pperprintsurfacetestpla'>http://www.filedropper.com/drr1pperprintsurfacetestpla'>http://www.filedropper.com/drr1pperprintsurfacetestpla

stl: http://www.filedropper.com/drr1pperprintsurfacetest

I will confess that i'm pretty burnt out from trying to troubleshoot this problem and getting it looking like m200 prints with respect to the visibility of layer lines but i'm starting to think it's not possible.

I've not seen or heard of anyone suffer this issue with an m200 before, though that may simply be a cause of me not looking hard enough ofc. But those i've spoken with multiple m200 workhorses have said they've not experienced anything like this on any of theirs and they all print consistently to the same quality.

 

Hi DrR1pper,

I've printed your "drr1pperprintsurfacetest.gcode and drr1pperprintsurfacetest.stl".

Your file was h: 0.1 and double wall plus 10% infill... I used temp: 192 deg. Celsius and no heat bed, just glue stick.  Do you use Cura slicer?

I made a second print with the stl file with settings: height 0.06, single wall and infill 20% the other parameter as above.

As I do not have a good macro camera, I used a USB microscope to evaluate.

I've a little ringing in the prints, but that's prob. a little slack in the X/Y motor belts and a shaky table.  

The print is as good as your m200 and maybe a little better.

There will be a few pictures here.

First picture is from a high res. print h: 0.06 mm picture from flat side.

Edit: The wide parallell "dark gray" lines is infill (20%), due to one layer of transparent gray filament (Verbatim PLA gray).  

Second picture is done with a microscope of the area indicated in the first picture.

Note the notch in the upper left corner caused by glue and cold bed...

Third picture is the same as above from the other side, the angled stair side.

Fourth picture is done with a microscope of the area indicated in the third picture.

Then the picture of your gcode file with your setting height: 0.1mm, double wall, 10% infill and 192 deg. C hot end (by me).

Your gcode file print, flat side first.

Funny how this color change, it is gray! Hmm.

This picture is done with a microscope of the area indicated in the previous picture.

Then the steps side.

And the microscope view as indicated in the picture above. Yes the above picture is upside down...

Then we have a look at one of your pictures.

Here is The magnified area as shown in the previous picture.

This should be enough to make a final conclution in this matter, you have the missed step syndrome in your printer...

Thanks.

Torgeir.

Edited June 11, 2016 by Guest

[DrR1pper 4]

@Torgeir

Firstly....Damn it! Sorry. Sent you the wrong one clearly. I made a 0.1mm and 0.15mm layer height version and must have sent you/uploaded the wrong one ofc as it should have been 0.15mm.

Secondly....holy crap! Thank you for doing all that work for me! I really really appreciate it and you've given me a ton of hope!

May i ask for the gcode that you used for your print for me to test please? Also i used s3d for mine. Was yours printed with the glittery silver/grey pla filament that comes with the ultimaker? Lastly, my one was definitely printed at 0.15mm layer height.

Edited June 10, 2016 by Guest

[DrR1pper 4]

Btw, how these prints are oriented in this photo is not how they were printed. The bottom of each print is the right vertical face on each in this photo.

[DrR1pper 4]

After i've ran your gcode though (if you don't mind sharing it with me please), what do you think i should do to try to fix the problem then? Do you think it's the z axis as well or something else?

Thank you again. People weren't kidding when they said ultimaker has the most amazing and helpful spirit within the ultimaker community.

I have to say, as promising as your pictures are Torgeir, i still have this hint of skepticism that the printer can really print as well as you've shown there despite showing clear evidence that i can. That print just looks too good to be true LOL. But trust me...i want it to be real and you've given me the extra impetus to try and achieve it so thank you as well as the others whom have been so helpful too!

Edited June 10, 2016 by Guest

[Labern 775]

thats great news about the ob, will it come with any 'advanced' nozzles

...im assuming so, ill have something to look forward to!

 

It should come with at least one but this will be down to the 3D Solex resellers and what they will offer.

[cloakfiend 996]

Dont worry @DrR1pper you'll get there if you are persistent enough. Printing is not plug and play, you just need a fully functional printer, and those results @torgeir produced can be achieved by you too! and every time! effortlessly! This thread was originally for zebra stripes, which appear far more clearly the better your printer is actually printing because rather than seeing horizontal lines you see diagonal lines which are the issue 'zebra lines refers to. I think its stepper related.

this print was my second ever ABS print I tried out as a noob after a few weeks of owning my first UM2, there are no real bad lines and I was probably printing too hot. I was trying to see how detailed I could go with the nozzle and it has its issues but still the walls are not steppy.

Your prints should look like @torgeir s by default. But you must be aware that drastic changes in geometry will affect the surface consistency due to thermal dynamics.

[DrR1pper 4]

@cloakfiend Thanks for that.

Regarding...

 

But you must be aware that drastic changes in geometry will affect the surface consistency due to thermal dynamics.

But that's just the thing. On the m200, i've not experienced these lines on any of the prints whether small or large, complex geometry or simple geometry and with all their filaments (except for pc-abs that i haven't tried).

[cloakfiend 996]

no, i mean when you go from printing huge areas, to just tiny ones that require much less time to print. its unavoidable on any printer of this nature i would imagine, unless you change the temps or speed or both near the section when the model changes. thermal dynamics are unavoidable.

imagine printing a solid cube, and then near the top, just the edges of the cube, like a high rim, the amount of time drastically changes to print this so therefore the heat changes and time it takes to cool changes hence a slight change in the outside surface. this wont be an issue on your ramps gcode as the model is consistent in geometry.

its why you always get better quality printing either multiples of the same thing or just one object at a time rather than loads of different ones that are all different sizes.

Edited June 10, 2016 by Guest

[Torgeir 267]

@Torgeir

Firstly....Damn it! Sorry. Sent you the wrong one clearly. I made a 0.1mm and 0.15mm layer height version and must have sent you/uploaded the wrong one ofc as it should have been 0.15mm.

Secondly....holy crap! Thank you for doing all that work for me! I really really appreciate it and you've given me a ton of hope!

May i ask for the gcode that you used for your print for me to test please? Also i used s3d for mine. Was yours printed with the glittery silver/grey pla filament that comes with the ultimaker? Lastly, my one was definitely printed at 0.15mm layer height.

 

Hi DrR1pper,

Not a problem, but I'll think it would look even better with 0.15, at last in the foto.

Thank you for the flowers! Why not, I'm just as interested in this cause as you are.

Of corse, no problem, but how do we handle /share files in here.

Aha, s3d, this explain why I got the message like this when I tried to open your Gcode file in Cura:

«No file found in Gcode file.

This feature only work with Gcodes made by Cura 12.7 or newer.»

I used Cura 15.04.3 ! -Well, I printed it as is, and it started printing from the inner left corner.

No, I'm using the first filament I ever own; the Verbatim PLA gray(kind of transparent), black and white. But I like it like that, as it is very nice to see how the infill work in "test print" etc.

Thanks.

Torgeir.

[Torgeir 267]

Btw, how these prints are oriented in this photo is not how they were printed. The bottom of each print is the right vertical face on each in this photo.

 

Yes, I printed them as you say here; bottom at right side.

[DrR1pper 4]

ah ok, thank you Torgeir.

Can i try your version of the gcode you used to print the file on your um2 please?

[Torgeir 267]

After i've ran your gcode though (if you don't mind sharing it with me please), what do you think i should do to try to fix the problem then? Do you think it's the z axis as well or something else?

Thank you again. People weren't kidding when they said ultimaker has the most amazing and helpful spirit within the ultimaker community.

I have to say, as promising as your pictures are Torgeir, i still have this hint of skepticism that the printer can really print as well as you've shown there despite showing clear evidence that i can. That print just looks too good to be true LOL. But trust me...i want it to be real and you've given me the extra impetus to try and achieve it so thank you as well as the others whom have been so helpful too!

 

Hi DrR1pper,

Ok. You have the problem even if you printed this object 90 deg different (rotated) from this position.

The conclution is then; both X and Y steppers suffer of this problem.

If you try to print at 45 deg angle different from previous print, there should be an improvement in this print. Is it? Why not try?

Also, if you look closer to your print (in the area I've marked), you'll find tree different lenght in a row over the step down point. Those plastic treads tend go a little on the side, either outer or inner side of the previouse tread (hmm line). Remember, both X and Y can be one step more or less! This is the phenomen creating lines located over or under the predicted surface height in your special test print.

If there's a problem with the Z-axe, well this axe cannot create this short or long lines!

Z-axe failure; two thing, step too far down or miss steps, I.E. no step. If it dont step, next extruder round will prob. ruin your print. Too far down, opening in between lines. Many things can be said here I'm sure.

But; is there any slack in the Z-screw? Can you feel any slack when liftig/pushing down (at both sides of the two 12 mm shafts) the bed a litle? Does the stepper sound «heavy» loaded when going up and down, or at any place along the lenght of the shafts, is there any different there?

If no on all this questions, forget about the Z-axe.

A litle bit skeptic does no harm.

Well, I do hope my explanation here helps in understanding how missed steps «can» modify our 3D prints.

You know, when we come to this level of 3D printing we will see other problem, small details really counts here.

Thanks.

Torgeir.

[JJB 2]

Hi guys!

I wanna add some information regarding the Zebra Stripes.

I was having this problem and I didnt know what it was until I came across this thread.

I did the DRV8825 hack posted HERE and I can say it's 80% gone.

Heres a picture where you can see the problem to the right and the new print after the hack to the left. (I stopped the print because the result was already clear)

I know it looks like the problem is gone but after inspecting the new print you can clearly see that the stripes are there, the agle changed and they are more subtle:

It is important to mention that I only did the DRV8825 hack to the extruder driver.

[gr5 2,239]

> DRV8825 hack to the extruder driver.

Um. yeah. I think this is unrelated. The zebra strips on benchy only happen if you have a vertical wall that is *not* quite vertical (tilted a few degrees) and also not lined up with X or Y axis. In other words the part needs to be rotated in Z axis by about 1 degree and then tilt the walls in by a degree to get the issue that is discussed in this topic.

what you are showing is... I don't know what.

[gr5 2,239]

I guess your extruder is overstepping every 16 steps and creating a little extra blob? Makes no sense to me.

[JJB 2]

I guess your extruder is overstepping every 16 steps and creating a little extra blob?  Makes no sense to me.

 

But the hack kinda fixed the problem.

If I print single lines it looks like this:

You can clearly see that the extruder is overextruding at a constant rate (5.5mm) aprox.

Im using a direct drive extruder with a Mk7 hobbed gear.

That picture was taken before the hack.

EDIT: It is worth mentioning that I tried replacing the stepper motors and the drivers with no success, the stripes were still there.

EDIT2: Switched back to non hacked driver and installed repetier, the stripes are back. I guess Im having a different issue here, any advice?

Edited June 12, 2016 by Guest

[gr5 2,239]

Didn't you just say the blobs appear on glass with nonhacked driver and are gone with hacked driver? Then you went back to non hacked driver and blobs came back?

It sure sounds like you have strong evidence that it's probably the driver hack, no? I mean I find it hard to believe but isn't that your claim? I don't get why you say "different issue"?

[gr5 2,239]

Maybe it's the mk7 hobbed gear causing those blobs. Each blob is when the next tooth touches the filament?

[Torgeir 267]

Hi guys!

I wanna add some information regarding the Zebra Stripes.

I was having this problem and I didnt know what it was until I came across this thread.

I did the DRV8825 hack posted HERE and I can say it's 80% gone.

Heres a picture where you can see the problem to the right and the new print after the hack to the left. (I stopped the print because the result was already clear)

I know it looks like the problem is gone but after inspecting the new print you can clearly see that the stripes are there, the agle changed and they are more subtle:

It is important to mention that I only did the DRV8825 hack to the extruder driver.

 

Hi JJB,

This driver is in the "Pololu" family, and have the same feature of configuration (as we name it) as the one used in Ultimakers late family 3D printers (as far as I'll know). Actually your "hack" is just the same thing as I did with my printer, that is using "PoLolu A4988".

You said it improved your print about 80%, yes that was missing step, -but then there is some sign of it still, right. When things improve like this, we might wonder; is there still some missing steps? No there is not! So what could it be then, the answer is "production tolerances". It is maybe a cheap (Chinese?) stepper motor.

The truth is; those steppers might not stop at the "exact" same position when the current is reduced. This is actually true for every stepper motor, if we go "deep" enough into it...

This is why we still may have sign of those stripes, if we look close enough into it.

You can have a better stepper motor, or you can gear down the speed by 2 (sure using belt for this), in order to improve the print further.

All this said, however, most of the steppers today is made in China.

So, if you like to have “real good” quality, the stepper motors used here for X/Y play an important role.

Thanks.

Torgeir.

[DrR1pper 4]

Hi everyone,

I was going to post this into a new thread (as i know that I have hijacked this thread long enough...sorry about that) but i've decided to posted it here as a portion of it actually relates to this threads topic at hand. If you would prefer that i remove it though and post it someone else, please let me know.

So, I performed a really simply print test yesturday to see what the affects of print temperature and print speed have on the visibility of layer lines/layer banding on practically all of my um2+ prints.

I also printed one on the m200 so that i had something to compare against and to my surprise, i believe that i am seeing zebra stripes on this m200 print. Something i had checked for in the past and not observed.

It was printed in z-abs and here is that z-abs print (on the left) next to one printed in z-ultrat (on the right).

I don't believe i have ever noticed zebra stripes on the m200 before but it could very well have been there in many prints only i just never noticed it (though i'm finding it hard to believe to be probably however possible as it's not exactly subtle, at least not in these prints). I've printed the benchy and the other test objects shown in this thread that presented noticeable zebra stripes on the um2 and other printers on more than one occasion on the m200 and could swear that i never saw any zebra stripes of any kind in the slightest. But I'm starting to doubt myself, so i'll run a battery of test soon to double check as i threw those old prints away.

Edited June 20, 2016 by Guest