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pictorial print issue identifier

Posted by rrr7 
Re: pictorial print issue identifier
April 15, 2015 04:46AM
Quote
rhmorrison
Z-wobble

Thanks. Will read those topics.
I already changed my threaded rods for the z-axis for other ones since they were really wobbly. Result stayed exactly the same, no difference at all, so I'm thinking that it isn't the problem.
Or there must be a different way to fix z-wobble

Link to video with old curved threaded rods;



Link to video with new straight (better) threaded rods;



The print result looks exactly the same, no improvement what so ever... sad smiley
Re: pictorial print issue identifier
April 19, 2015 06:01PM
Did you try any other colour?
I`m printing with esun pla and when I print in white, I have the same ribs (or z wobble that was mentioned) and my prints looks exactly like yours, I can change over to silver or blue esun pla with exactly the same settings and the same prints are as smooth as a baby`s butt. Think I have E steps issues with white, temperature issues or my white pla drank too much water.......don`t know.
Re: pictorial print issue identifier
April 21, 2015 08:04AM
Hi Bking1340. Haven't tried printed a different color filament with the same settings. Will do and let you know!
Thanks smiling smiley
Re: pictorial print issue identifier
May 14, 2015 05:52AM
Have you guys seen this guide from/for (?) ultimaker yet?
[support.3dverkstan.se]
Hopefully can help some people (will most likely not only apply to ultimaker machines) smiling smiley


3D Drucker:
Prusa i3 (Alu "Rahmen", Heated Bed, Bowden Extruder, E3D-V6 Hotend (Klon), RAMPS 1.4, A4988 (extruder)/DRV8825 (x/y/z) Stepper Treiber, Marlin 1.1.0 RC2, Reworked Plastikteile)
Re: pictorial print issue identifier
June 19, 2015 10:13AM
Thats wonderful help. Thanks for linking.
Re: pictorial print issue identifier
August 26, 2015 11:59AM
I have written my own print troubleshooting pictorial guide and have kept all photos, so I'll join the club with the reprap PTPG page!
Re: pictorial print issue identifier
October 04, 2015 05:29PM
Hi, this is a great thread, but most of them had no picture or insufficient or hardly can be seen without marker. Can those be fixed?
Re: pictorial print issue identifier
October 29, 2015 12:15AM
Awesome resource just put up by Simplify3D, with LOTS of pictures:

[www.simplify3d.com]
Re: pictorial print issue identifier
January 05, 2016 05:27AM
I just added a picture for insufficient material extrusion. This took my a while to figure out. My printer had been working fine, but then started producing totally unusable output. Turns out I somehow changed the filament diameter setting in Slic3r to 3mm instead of 1.75mm. I'll try and take a few more pictures of the failures. Although my problem wasn't on the page yet, this page was VERY helpful ruling things out.

-Matt
Re: pictorial print issue identifier
February 28, 2016 11:57AM
Could someone tell me what this is?
Doesnt look like a z-wobble imho.


Printed in vase mode with 0,05 layer in the bottom.
Speed is about 20 mm/s.
PETG 220°C
Modified Geeetech Prusa i3 X

thanks
kev0

Edited 1 time(s). Last edit at 02/28/2016 12:00PM by Kev0.
Re: pictorial print issue identifier
May 03, 2016 01:18AM
Hi
I am a newbie. I just buy a prusa i3, i update firmware 1.1.0-rc3. then try to print Wades extruder from thingiverse with cura. It look like the the X axis problem, but i dont know why and how to fix. This is a part of first layer,
please help me.
Thanks
Attachments:
open | download - IMG_20160503_1438061.jpg (183.6 KB)
Re: pictorial print issue identifier
March 29, 2017 07:25AM
I have a possibly challenging print issue for you all.

First of all, some specs.
PLA
Layer height: 0.2mm
Normal size benchy
Slicer: Prusa3D Slic3r MK2 with modified Prusa profiles.
Printer is a 1.75mm modified bowden printer. Printer is mostly redesigned by myself.
Here is a shot of the print head.


I'm struggling with strange lines on my prints. I don't know what I can do about this. All lines are geometry related. The lines are always at places where something in the geometry of the entire print is changing. The lines are consistent and always at the same place in every benchy print.

The deck is visible in the perimeters. This can only be seen at this side of the boat.


More strange lines



The lines are even worse at the inside of the bow.



And there are some blobs. These are start and stop points. I don't think there is anything I can do about this.


Things I tried
- Infill/perimeters overlap set to from 25% to 15% and 0% . This make things even worse
- External perimeters first. This removes the deck poking through the outer perimeter. The rest of the print was way worse.
- Belts are tightened.

I running out of ideas. What is causing this?

If you need more information, please let me know. smiling smiley

Edited 4 time(s). Last edit at 03/29/2017 10:01AM by JanJans.
Re: pictorial print issue identifier
March 29, 2017 10:46AM
The last picture is a feature thats not printing very well. The back of benchy is supposed to say #3DBenchy. Although I've never had this come out unless I print benchy at 0.15mm layers.


Re: pictorial print issue identifier
March 29, 2017 11:14AM
I am aware of this. However, the blobs are also outside the text box area. This shouldn't happen in an ideal world grinning smiley
Re: pictorial print issue identifier
March 30, 2017 02:15AM
That's odd. Sometimes I have similar lines. Looks like a layer shifting, but only for (part of) a layer. Next layer is fine again. I know it only looks like shifting, but it isn't.
It turned out that one of my smooth Z rod fixations had a loose screw. I fixed the screw, and the lines disappeared. Now they came back, but I haven't found the reason.
You could check all your Z rod & fixing parts for loose screws.

Edit: I still have another thing in mind - I got the idea that it makes a difference if the outer perimeter is done clockwise or counterclockwise. I printed a part few days ago, got those lines, and I'll check the GCode for this.

Edited 1 time(s). Last edit at 03/30/2017 02:17AM by Inhumierer.
Re: pictorial print issue identifier
March 30, 2017 08:32AM
I doubt that has anything to do with the Z axis. All lines are geometry related. The lines are always at places where something in the geometry of the entire print is changing. If there a temporary misalignment in the print head it should be the X and Y axis. It would be interesting to change the orientation of the print just to see the effect of this on print quality. Printing the print on a pedestal could eliminate every doubt in the Z axis.

I think there can only be two explanations.
1. Print head is out of position for a entire layer
2. Print head is depositioning to much or to less material for some reason.

I think option 2 is more likely the case. Could this have something to do with the bowden setup? The bowden tube with filament acts like a big spring, messing up the accuracy of the extruder. Perhaps more heat (reducing extrusion force) can hide this problem. I could try this.
Re: pictorial print issue identifier
March 30, 2017 08:40AM
Considering your thought being option 2, it could be a case on inconsistent z heights. On one layer, maybe your Z is moving 0.2mm, and on the next layer it moved 0.21mm and the subsequent layer moved to 0.19mm due to some sort of slight mechanical miss alignment or if somethings slightly bent or not completely square. The layer movements that go to 0.19 instead of 0.2 could also make it look bulged out as it would be squishing the plastic more than normal making it look like over and under extrusion.
Re: pictorial print issue identifier
March 30, 2017 10:02AM
That is true.
Although it doesn't really explain the relationship between the lines and the change in geometry of the print. It would be a strange coincident that the Z height fault would occur at exactly these locations.
Re: pictorial print issue identifier
March 30, 2017 10:53AM
Update: I checked all my Z axis fixings, all look good. I checked my hotend, and I noticed that it could move a tiny little bit, with enough force. Fixed it, now looking for something to print...
Re: pictorial print issue identifier
March 30, 2017 12:55PM
Quote
Inhumierer
Fixed it, now looking for something to print...

IMO, you can never have enough #3DBenchy models or Marvin key chains. Those always seem to be my go-to test prints these days. The Marvin key ring is always a good test for retraction and ooze on the topside of his head and the actual key ring loop.
Re: pictorial print issue identifier
March 31, 2017 01:40AM
I'm building a housing for my Mendel90 and there are a few parts missing. I printed two of them with tall smooth walls, and - tataaa - they look perfect. So my issue was indeed a loose Z rod, even if the problem didn't look like a Z axis problem, and a loose hotend.
Re: pictorial print issue identifier
April 02, 2017 01:16AM
I have been busy too. Yesterday I checked the mechanics of the printer. I couldn't find anything wrong with the Z axis. The Y axis however as a some play on the bearing of the print head carriage. The play is pushed consistently to one side by means of gravity. Perhaps this in not always the case when accelerating violently. I will try to replace this bearing. The bearing glued inside the aluminium housing. This could be problem.

Nevertheless I printed 3 benchys yesterday. I tried 3 different settings.
1) Printed without the cover on the printer. The cables are grinding against the cover. This could influence accuracy. There was no increase in print quality.
2) Rotated the benchy 90 degrees. The strange lines on the print relocated to other places on the print. The overall print quality was unchanged.
3) Increased the printing temperature with 10 degrees celcius. Perhaps a slight improvement in print quality.

I will replace the bearing and print a new bency. If this doesn't increase print quality then I think I going to mount the extruder on top of the print head as an experiment. This will reduce the bowden tube length significantly. This could eliminate my doubts surrounding the bowden system. You can really feel the flexibility of the bowden system when you push filament true the bowden tube by hand. Perhaps a 1.75mm bowden configuration is not a good idea.

Edited 1 time(s). Last edit at 04/02/2017 01:51AM by JanJans.
Re: pictorial print issue identifier
April 08, 2017 10:45AM
Update!
I ditched the bowden system. I went from this



To this. The extruder is temporarily held in place by tape and tyraps.



The increase in print quality is amazing! I should have done this earlier.

However, there are still some lines in the print. You cant feel the lines any more though. This is a big improvement.


The deck is still poking through. No change there, but all other lines are a lot less visible.


I discovered that the lines are highly sensitive to the extrusion multiplier. Higher extrusion multiplier values increase the thickness of the lines.

However, there are two issues that are more visible with this set up. There are gaps in the top surface. These are consistent between the prints. you can see that the gaps are not consistent between the layers.



This has lead me to believe that there is stretch in the X and Y axis belts. One of the problems with this printer is the placement of the X en Y axis motors. They are placed at the bottom of the printer. The printer itself is rather large. Therefore there are very long belts between the motor and the motion mechanism on top of the printer. This could also be a good explanation for the deck poking through. Changing the motor location will be challenging.

Edited 4 time(s). Last edit at 04/08/2017 10:49AM by JanJans.
Re: pictorial print issue identifier
May 13, 2017 03:49AM
Update!
I replaced the belts with new steel wire ones. These have a new belts have significantly less stretch than the kevlar ones. I was shocked when I discovered that the original belts where the wrong types! The pulleys where GT2 pulleys and they where using MXL belts! That explains a lot! The designers of this printer are noobs to say the least.

The print quality again improved significantly. I still have some issues with strange lines but those are small issues. The overall print quality is really good!

Re: pictorial print issue identifier
August 31, 2017 11:44AM
Mechabits4772.jpg

It's almost like digital Braille, but whats it telling me, besides the bottom layers...should have checked adjustment.
About 5mm up I get an almost perfect line, i had hit 1.1 on extrusion multiplier by mistake somewhere in the print
then I have some nicely aligned stepped lines, belt? or microsteps? I think microsteps
as higher up they double up(when speed slows) but stay aligned, but it's difficult to know which defects are just from the layer below
there's 2 diag' lines, I assume that's some staggered Z hop/retraction? should I check vref's at some point?

Wondering if best improvement would come from Direct Drive or 32bit...

So what does it tell you guys?

Edited 1 time(s). Last edit at 08/31/2017 08:25PM by MechaBits.
fma
Re: pictorial print issue identifier
October 06, 2017 12:03AM
Our hackerspace started this 'Reprap Print Doctor': [www.logre.eu]

But it is in french...


Frédéric
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