Vertical lines on my prints. (This is not infill showing)  

Page 1 / 2
  RSS
Hooch
(@hooch)
Trusted Member

Hi.
I have this problem you can see on the images attached.
This is NOT infill showing. I checked it. What could it be?

Posted : 16/11/2020 10:00 pm
--
 --
(@)
Illustrious Member

Those are normal vertical surface artifacts. Part of printing in layers with stepper motors.

Posted : 16/11/2020 10:18 pm
Hooch
(@hooch)
Trusted Member

So those are visible "steps" of those motors? If so then it would be nice to have BLDC with encoders.

Posted : 17/11/2020 8:30 am
Neophyl
(@neophyl)
Famed Member

There is an absolutely enormous thread on this issue if you feel like spending a few hours reading 🙂 

https://forum.prusaprinters.org/forum/original-prusa-i3-mk3s-mk3-user-mods-octoprint-enclosures-nozzles-.../stepper-motor-upgrades-to-eliminate-vfa-s-vertical-fine-artifacts/

Posted : 17/11/2020 8:33 am
--
 --
(@)
Illustrious Member

@hooch

I'm curious, what sort of surface quality were you expecting from a 3D printer? 

And no - those are not steps, but artifacts of a moving mass, harmonic resonances, and general interaction of multiple noise sources affecting fluidic flow of melted filament. Some can be adjusted for slightly better performance using obtuse calibrations; some can be affected by modifying firmware, some require radical hardware changes. Most all is in the thread Neo listed.

This post was modified 7 months ago by --
Posted : 17/11/2020 8:50 am
Hooch
(@hooch)
Trusted Member

I read some of it. Now I see that I assembled my printer very well, because those VFAs are the really the only issues I have.

Posted : 17/11/2020 9:03 am
Hooch
(@hooch)
Trusted Member

@tim-m30

To be truthful, when printer is moving in only 1 direction I expected the edge to be "flat". As those ridges are in the direction of other axis (that is stationary at the moment)

Posted : 17/11/2020 9:07 am
--
 --
(@)
Illustrious Member

That's the spuriousness of it. Moving even in only one direction will have artifacts. Any variation in travel motion will allow fat and thin spots in extrusion. Thus, an artifact in the vertical wall. Add the fact the extruder motor is moving to push filament, too; you have two sources of artifacts in any axis. Then add the gear driving the extrusion process may or may not be perfect, now it's three. 

I've satisfied myself even the belt pitch in the Mk3 adds to the patterns. While good, not every notch in the belt is the exact same dimension, and this shows up in walls.  That would be an issue even with encoded servos.

Posted : 17/11/2020 2:29 pm
vintagepc
(@vintagepc)
Noble Member

Part of the problem is that steppers are non linear to a degree. Hackaday has a nice writeup on this - 

https://hackaday.com/2016/08/29/how-accurate-is-microstepping-really/

As pointed out, it's quite a complex issue arising in a combination of software and hardware. Some folks have had success with software adjustments, others with changing their motors (I'm in this camp) and yet others with both, or no success at all. There are many, many factors at play and there is not one "golden" cause to fix it. 

Posted : 17/11/2020 2:50 pm
ILovePrusa74
(@iloveprusa74)
Active Member

@tim-2

I have the same vertical lines. I am often printing figures for friends and they look ugly. I expect better print quality from a 769€ prusa printer then from my 259€ Anycubic. My Anycubic produces absolutely no vertical lines. 

I don't know why prusa is so hyped. I bought one and I have many problems with my prusa: y crash detection without any crash. The vertical lines. And a lot of different other problems at the beginning, which I have solved now. But to hear these vertical lines can not be solved are really bad news.

First I was just disappointed from my new printer but now I start to hate it and I regret that I have bought it.

All say cheap China printers are bad, but they are not for there price and with minimum additional money you can make them really good and they are still half the price of the prusa

I expect the very best quality from a prusa. And if there is a common problem with vertical lines I want it to be solved by prusa and not hear that I have to buy new stepper motors with 0,9 degree steps and modify my firmware by my self.

Posted : 12/05/2021 7:23 am
cwbullet
(@cwbullet)
Illustrious Member

@iloveprusa74

Anycubic is not bad, but is not a Prusa.  If you get a good one, they work.  If you get a bad one, good luck getting support.  

 

--------------------
Chuck H
3D Printer Review Blog...
Posted : 12/05/2021 11:50 am
Dan Rogers
(@dan-rogers)
Prominent Member

I changed out my X and Y motor just for shits and giggles to see if I could get an improvement.  There was, but the biggest improvement was the motor noise was greatly reduced.  Think about the comments above - highly fluid compound being dropped in space and crushed against the prior layer - noise is a reflection of the smoothness of the movements - and this is the "modem whine" you hear when certain orientations are printed together.  The motors harmonically beat against each other and the noise you hear is being transmitted through the molten filament.

Even without changing out motors, which for me was a hobbyist experiment with my hobby plastic spitting robot (MK3s) I found that I could dial away those lines by just rotating the part on the bed so the high noise moves were avoided.  The extruder motor also has a direct impact on the waves of noise flowing through the molten plastic - but I didn't change that one out.  Another trick is to soften your belts just a touch - that smooths out the belt imperfection contribution.

The newest firmware release *.*.10 has an experimental setting that changes the way the steps are managed in the software.  It should smooth out extruder noise (my understanding is the experimental menu setting for this only applies the change to the extruder motor.).  I'm waiting for the next slicer release and then will try that firmware upgrade (the upgrade has some features that are only supported in the next slicer release).

Finally, if you hate your MK3s+, where are you located and what do you want for it.  My business is picking up and I will need another one sometime this year if the sales volume for my lures keeps ticking up.

 

Posted : 12/05/2021 2:39 pm
ILovePrusa74
(@iloveprusa74)
Active Member

@dan-rogers

Thank you for your reply. I have contacted prusa support which is very good. I try to find a solution.

Sorry for my bad comment this morning. I was charged with bad emotions. I do not hate prusa or the printer. I love my new printer but it is all so difficult with it.

I am so tired of trying to find solutions for problems. And I was frightened by the fact that so many people seem to have this vertical line problem but no one in no forum ever found a solution. 

I hope this problem will be solved quickly.

My belts are very loose. Or what do you mean by soften the belts?

I will try the new firmware. But if it's a bad stepper motor then this will make no change.

I don't think it's the extruder stepper because the lines are stronger when print head moves parallel to y.

I have sent an example picture with this post

Posted : 12/05/2021 3:03 pm
--
 --
(@)
Illustrious Member

The motors have 180 steps per rotation and they are then microstepped 256 times to add resolution. One rotation of the motor is about 32 mm of travel (going form memory - I might have the math wrong). So final steps are not microscopic and are visible. The extruder is also stepping to extrude plastic at a finite resolution.

Then add in contributing issues like loose belts, or tight belts, or poorly attached drive gears that all amplify stepping artifacts, you will get visual artifacts. But if you actually measure the amplitude of these artifacts, they are sub-millimeter, almost microscopic. Light is just a great way to show off microscopic defects. By bouncing light off the part you can see defects that are even beyond microscopic. 

The only way to ensure a perfectly smooth surface that isn't going to show artifacts under good lighting conditions is to mold it or sand and polish the part you want. Or, get a printer with grand resolution, like an SLA type, where the 'pixel' size is microscopic. Even then, with the right light, you'll still see artifacts.

 

This post was modified 1 month ago 3 times by --
Posted : 12/05/2021 6:37 pm
Dan Rogers
(@dan-rogers)
Prominent Member

@iloveprusa74

I did not mean to infer there is anything wrong with the steppers that come with the printer.  Their resolution is what it is.  I did not change them out because they were bad, I just wanted to try out the Moons steppers which have a slightly different behavior (no jiggle at the end of each full turn, in layperson terms).  They did improve my VFA's but as you are reading in other threads here - an FDM printer is not going to ever be free of some artifacts on the final print - whether it is layer lines, or VFA's on very thin vertical walls.  If you thicken that wall up, the VFA's become nearly indistinguishable.  If you sand the print, you can make them go away, and then with a little clear coat you get the smooth gloss you are looking for.

If your belts are very loose (remember, you cannot tell belt tension with the built in #'s on the control panel, not really, as those measure drag, not tension).  Print out in Prusament PETG (only Prusament PETG) the belt tension gauge you can download from the print library.  That will help you dial in your belts.  

Your picture also indicates probably needing to tweak the cooling on that print - the walls look like they warped.

Each different model with each filament will often need fussing with to get as close to perfect as possible - do invest in some files and sanding pads (150 and 280 grit are what I use) and then if you need to get smoother than that, go to wet-dry paper and wet sand to the level of gloss you want.

My VFA's are not gone - but they did reduce some - but that is because I didn't change out the extruder motor because I bought the 1 amp motors for X and Y.  The extruder does far more work and runs at higher current in firmware versions below the newest *.*.10 - which has that experimental menu setting that allows the extruder to run cooler (at lower amperage)

Posted : 12/05/2021 7:10 pm
--
 --
(@)
Illustrious Member

Stepping on to soap box:

What I find humorous in all of this is people buy a cheap printer ($750 is cheap) and expect million dollar performance from it. It's also fun to watch people spend hundreds more to make it better, and as far as I can tell most of these improvements aren't.  Sure - there are tangible differences for some of the upgrades, but it is still an FDM printer with steppers with finite vertical resolution and a 0.4 mm nozzle (0.15 mm if you are adventurous). Even folks who have upgraded to the best steppers out there, and replaced the extruder with a geared version to further increase resolution still have artifacts on their prints. Some even turn to ABS and vapor etching to further reduce the surface to remove FDM artifacts. In the end, if you look close, there will still be identifiable artifacts that show you printed the object.

I'm also just as amazed as I am amused by these efforts. It shows just how enthusiastic people are in their hobbies. I'm actually jealous in some ways -- so please, don't take my comments in a negative way. In the end, the enthusiasm is contagious, and nearly everyone benefits. 

However, it's just like the kid who gets a peddle car for Christmas, but isn't happy it isn't motorized. Or the one that gets the electric version, but complains it isn't as fast as dad's gas go cart.  You want a plane, get one, then complain it isn't a Lear. You wanted to be an astronaut and get to orbit but never get to the moon... lol

Sigh - what it means to be human.

Stepping off soap box now.

This post was modified 1 month ago by --
Posted : 12/05/2021 7:42 pm
cwbullet
(@cwbullet)
Illustrious Member
Posted by: @tim-2

Stepping on to soap box:

$750 is cheap

Say it again, brother, say it again.  

 

--------------------
Chuck H
3D Printer Review Blog...
Posted : 12/05/2021 8:31 pm
--
 --
(@)
Illustrious Member
Posted by: @cwbullet
Posted by: @tim-2

Stepping on to soap box:

$750 is cheap

Say it again, brother, say it again.  

Hmm - how many $30 spools of filament did I use last year? I know last weeks trash can had 7 empties...

Posted : 12/05/2021 8:53 pm
ILovePrusa74
(@iloveprusa74)
Active Member

I just wanted to say thank you for your answers and your advice.

I just wanted to give an update. Prusa support told me to print a xyz cube and then call back. But I never did.

I printed the cube and then ignored belt status and did what I always did with my Anycubic. Tension the belts intuitively.

After this I did a new test print and the results are much better. I also made sure everything runs smoothly.

I added a photo of y. The cube at the bottom was first and at the top was second print.

X ist still better but I think I have to live with the result. Or spent 100 dollar for new steppers and change firmware. No thanks. 🙂

Posted : 15/05/2021 9:14 pm
ILovePrusa74
(@iloveprusa74)
Active Member

This is x

Posted : 15/05/2021 9:15 pm
Page 1 / 2
Share:

Please Login or Register