Stringing, artifacts, and rough looking overhangs on prints after changing hotend
 

Stringing, artifacts, and rough looking overhangs on prints after changing hotend  

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jody.n2
(@jody-n2)
Eminent Member

So, awhile back I had jams on almost all PLA prints over 30 minutes. So after many hours on prusa support I just decided to buy a new hotend(genuine e3d from prusa3d). Unfortunately, now I have stringing, artifacts, and rough looking surfaces on some overhangs(didn't look into overhang too much yet). I typically don't like to mess with prusaslicer settings and would just try to fix it if i'm looking at an hardware issue.

When I contacted support for the problem they had me mess with retraction settings and nothing I did there made a positive difference. When they had me lower the temp by 10 degrees it did get a little better but really not that amazing. They also had me test thermistor and heater with multi-meter and they were fine. They also had me try silicone sock(I had one just don't like using them from bad experience). I believe they wanted me to try that because they thought temperature was unstable. However, temperature is very stable. I am missing some other stuff they had me try but I honestly cant remember. Unfortunately, at the end of chat they recommended I either just pull the strings off with pliers or send the printer in to be serviced. But the printer is out of warranty so I would have to pay for it to be serviced. If that is my best option I guess I could go that route to just not trying to throw too much money at problem.

So here are a couple frogs I printed in a quite new roll of opal green prusament. I also did try printing stringing tests on other brands of filament new and used but they all had same problem. I also did have to print a prototype of something with petg and it had some stringing too.

.4 mm nozzle .05mm layer height frog

.25mm nozzle .05mm layer height frog (some stringing already removed). you can also see rough overhang here.

Zoomed in picture showing some of the artifacts on leg of frog with .4mm nozzle

  

 

This topic was modified 6 months ago by jody.n2
Posted : 19/07/2020 1:40 pm
Peter M
(@peter-m-3)
Prominent Member

Printing 0.05 is I think difficult.

So try first 0.2 mm to see if this works.

Do you print in a enclosure, how hot is it where you print, give more info if possible.

Let us see a picture of your first layer.

Adjust the spring of the extruder, and retraction settings will be important(for 0.05 setting), test first with 0.2 with standard settings.

Posted : 19/07/2020 6:29 pm
jody.n2 liked
karl-herbert
(@karl-herbert)
Famed Member

@peter-m26

0.05mm layer height is very difficult to print with a 0.4mm nozzle. Small nozzles (0.25, 0.15) are more suitable for this. The print bed must be well leveled and the first layer must be exactly right.

to reduce stringing you can try the following:

- change retraction distance and speed

- decrease printtemp. and printspeed

- avoid long movements (try it with change seam settings)

- increase frontfan speed

- clean nozzle before printing

- keep your filaments moisture free

This post was modified 6 months ago by karl-herbert
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 19/07/2020 6:41 pm
jody.n2 liked
jody.n2
(@jody-n2)
Eminent Member

@peter-m26

Thanks for the reply.

I have had this printer for over a year and I have done many prints with .05mm layer heights before and they are typically near flawless. I know my printer is or at least was very capable.

I am away from printer right now but here is a stringing test I did at .2mm layer heights

I don't print with a enclosure, the room I print in is typically about 70-75 degrees ferinheight.

I can get a picture of first layer later, I believe it is pretty good but I can post a picture later when I have access to printer.

I can run this frog at .2mm layer height later. Tension seems ok but I've messed with it a little throughout troubleshooting.

I previously forgot to mention that I also checked ptfe tube.

It is just frustrating because I know this printer is capable of much better results. It may not seem like a big deal but this issue is really irritating to me.

 

Posted : 19/07/2020 6:52 pm
jody.n2
(@jody-n2)
Eminent Member
Posted by: @karl-herbert

@peter-m26

0.05mm layer height is very difficult to print with a 0.4mm nozzle. Small nozzles (0.25, 0.15) are more suitable for this. The print bed must be well leveled and the first layer must be exactly right.

to reduce stringing you can try the following:

- change retraction distance and speed

- decrease printtemp. and printspeed

- avoid long movements (try it with change seam settings)

- increase frontfan speed

- clean nozzle before printing

- keep your filaments moisture free

Thanks for the reply 

I did print one of those frogs with a .25mm nozzle. 

Messing with retraction distance did nothing in my testing except once I hit about 2mm test print looked awful. I upped speed with little improvement. 

Decreasing print temp did have some effect. Haven't tried changing print speed. Will look into that

Ok, I will look at those seam settings. First I have seen of this thanks

frontfan is at 100% already unfortunately

I make sure to clean nozzle

I keep all my filament in plastic bags with silica packets, and also made sure to try a unopened roll and saw no difference.

Again I am just really frustrated because I never used to have this problem making me think its a hardware issue when I changed hotend. I would much rather pay for a hardware fix then fight it in software but I will keep trying to anyway.

Posted : 19/07/2020 7:04 pm
karl-herbert
(@karl-herbert)
Famed Member

@jody-n2,

do you have the stringing problem with other filaments? I print a lot of Nylon (PA12) and stringing can hardly be avoided but at least reduced with the actions mentioned above.

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 19/07/2020 7:27 pm
jody.n2
(@jody-n2)
Eminent Member

@karl-herbert

I print almost exclusively with pla and petg. The prints shown are prusament pla. Stringing is about the same for both filaments. I think ive had a slight amount of stringing with petg(not like this) before. But never with pla. When I print with flexible I just expect it, with pla I never saw it until now.

This post was modified 6 months ago 2 times by jody.n2
Posted : 19/07/2020 7:30 pm
karl-herbert
(@karl-herbert)
Famed Member
Posted by: @jody-n2

Again I am just really frustrated because I never used to have this problem making me think its a hardware issue when I changed hotend. I would much rather pay for a hardware fix then fight it in software but I will keep trying to anyway.

Do you use the original E3D hotend?
If you can exclude everything on the software side (which is not so easy), I would check the hotend. Is the PTFE tube ok (correct length with chamfers) and does it fit correctly. Drive pulleys and idler tension also ok and the filament loading is smooth? Maybe test a new brass nozzle.

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 19/07/2020 8:42 pm
jody.n2 liked
jody.n2
(@jody-n2)
Eminent Member

@karl-herbert

Yes, the one I swapped out for is a genuine e3d from prusa store. The ptfe appears to be ok. I didnt measure it when I took it out took pictures for support and they didnt see anything wrong with it.

Filament loads ok. I always felt idler tension is a bit weird as it grabs filament even if other side is not screwed in but I made sure to have it screwed in proper distance. Drive pulleys appear ok. I tested both my .4 and .25mm nozzle the .25mm was pretty much new. But I can try a new .4mm nozzle tonight. I have a couple spares.

Posted : 19/07/2020 8:55 pm
jody.n2
(@jody-n2)
Eminent Member

@karl-herbert

@peter-m26

Good news after swapping nozzle I printed a .2mm frog and it seemed pretty good! Here is previously requested photo of first layer(I realize its probably a little high I just calibrated it after swapping nozzle and could probably be better). I did no changes with print settings with assumption that it was hardware problem.

Here is finished print👇

I will be running a stringing test and try a higher res frog but this seems ok. Im not going to call it solved yet but if next couple prints are ok then I will.

Thank you for the advice/suggestions.

This post was modified 6 months ago by jody.n2
Posted : 20/07/2020 7:08 pm
karl-herbert
(@karl-herbert)
Famed Member

@jody-n2

That looks good. I would be glad to hear from you if it works with a layer height of 0.05mm without stringing.
What such a nozzle change can do! For this reason, I only buy high quality brass nozzles.

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 20/07/2020 7:27 pm
jody.n2
(@jody-n2)
Eminent Member

@karl-herbert

Well I may have spoke a little soon because stringing test was still pretty awful. Im printing a .05mm frog anyway. I am also considering maybe trying my old hotend for a stringing test after that to see if that would change things. It jams on pla quite a bit but it would probably be ok for a test. If that doesn't work then I guess print settings will be my only other option. 

Posted : 20/07/2020 7:36 pm
karl-herbert
(@karl-herbert)
Famed Member

@jody-n2

A very persistent phenomenon. Should this change when using the old hotend, it would be interesting to investigate this more closely or compare it with the new hotend. But if everything was installed correctly, I can hardly imagine that this is the cause. So I'm curious.

This post was modified 6 months ago by karl-herbert
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 20/07/2020 7:48 pm
jody.n2
(@jody-n2)
Eminent Member

@karl-herbert

Hey, I might just be replacing thermistor now. I tried printing at 195 instead of 215 which is the lowest I have gone and saw very good results.

The thermistor was reading 1-2 degrees below bed temp at room temp but I didn't think much of it but maybe its proportional.

Posted : 21/07/2020 3:09 am
karl-herbert
(@karl-herbert)
Famed Member

@jody-n2

Here a thermistor table overview (Semitec 104GT):

Temperaturtabelle für Thermistor Semitec 104GT

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 21/07/2020 4:00 pm
jody.n2 liked
jody.n2
(@jody-n2)
Eminent Member

@karl-herbert

thanks for the handy chart. It actually seemed ok it is about 24 Celsius and it read 22 on printer and tested at 101 on multi meter. But other thermister I had off old hotend read 25 degrees celcius on printer and tested at 105 on multimeter. Although that doesn't seem to quite line up as I would expect resistance to be lower.

Anyway I swapped the thermistors and ended up with this

its not great but it is quite a bit better. Will have to see how notable it is on other prints. I never actually ran stringing test with it previously. Maybe after that I will try and fight it with settings a bit too.

Posted : 21/07/2020 8:03 pm
karl-herbert
(@karl-herbert)
Famed Member

@jody-n2

The thermistors differ from each other because they are subject to a tolerance range. The temperature is not measured directly but is calculated by changing the resistance according to a table. Deviations of 5 degrees C. or more can occur. I would simply adjust the print temperature for each filament until the result fits, no matter what value is shown on the LCD display.

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen....
Posted : 21/07/2020 8:45 pm
jody.n2 liked
3Dean Printing
(@3dean-printing)
Active Member

Interesting case that's going on. I've had this issue whenever i print 0.07mm or less. You can try to calibrate the hotend temperature in the calibration menu. Its called Temperature Calibration. I use this whenever I have stringing while adjusting the temperature/retraction settings. It could be that your filament needs to be dried. I recently got a new hotend too but never had an issue like you. How long have you had the filament you've been testing with? I dry my filament as much as possible or at least once a month. Hope this helps.

I'm a high school student who has had the MK3S MMU2S for a year and have had a lot of successful prints. I try to help as much as I can....
Posted : 21/07/2020 11:58 pm
jody.n2 liked
jody.n2
(@jody-n2)
Eminent Member

@pro_grammer

Thanks for the reply. I tried very hard to make sure filament was not a factor the roll of prusament I am using is 2 weeks old and has been kept in a bag with silica packet whenever not in use. I also tried a fresh roll(gizmodorks) to be safe. Have not looked at that temp calibration thanks. Will look at that. With my limited testing when switching thermistor back it appears I have some stringing and a ugliness to .05mm layer height prints. I will try that temp calibration, then mess with settings as it seems almost entirely based on temperature. I have had this printer for quite awhile and had saw temp calibration before but kind of forgot about it.

Posted : 22/07/2020 12:30 am
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