Prusament PLA Stops Extruding Mid-Print  

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adi_pen
(@adi_pen)
New Member

I recently bought some Prusament PLA and there have been issues from day 1 with prints not printing fully and having some extrusion problems. I thought it was heat creep but it doesn't occur on the other PLA I own and the PETG that I own as well. Whenever I pull out the filament after it stops extruding, it has some transparent stringing on it. I've attached images below if anyone can help, I'd be very grateful!

Posted : 09/02/2021 3:42 am
GunnerP
(@gunnerp)
Eminent Member

Is your printer in an enclosure? If so, even though you don't have issues with other PLA filament, that doesn't mean heat creep isn't the issue. I have an enclosure that stays around 85-90F (29-32C) during a print and some PLA works fine while some jams due to heat creep. Different manufacturers have their own plastic formulations that vary slightly, which can effect how different filaments brands of the same material react to heat. Different colors can also change how the filament behaves, even if it is the same manufacturer.

Also, have you printed any other filaments besides the PLA and PETG recently?

This post was modified 4 months ago by GunnerP
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Posted : 17/02/2021 2:44 am
JirohP
(@jirohp)
Active Member

Hi,

I am having the same problem, the print will be running fine and then the extruder starts clicking and while it is clicking it isn't feeding. We have tried cold pulls, and replaced the nozzle.  This only really became a problem after we upgraded to Mk2.5S and put the printer into the ikea lack enclosure. Taking the enclosure off tends to fix it, butI thought it was friction for the feed.

Is it likely to be the enclosure causing the system to run too hot?

JirohP

Posted : 02/05/2021 10:01 pm
Lize
 Lize
(@lize)
Estimable Member

Yes, if I forget to run with my cabinet doors open when printing PLA then it gets too hot and the extruder starts clicking. I have a large cabinet and in my case if it gets much above 28C then the clicking will start a almost always 2 hours into the print.  Cold pull(s) is then necessary, if I stop the print quickly once the clicking starts then sometimes loading and unloading cleaning filament will cure.

Posted : 02/05/2021 10:25 pm
JirohP
(@jirohp)
Active Member

Thank you

I have been trying to fix this for months. I only use PLA and it has been driving me bonkers, some worked, some didn't I was trying to associate it with the layer height, friction on the spool, all sorts never knew too much heat in the cabinet could be a problem.

Looks like we'll just have to put up with the noise😆

Thank you!!!

Posted : 02/05/2021 11:12 pm
Lize
 Lize
(@lize)
Estimable Member

I hardly notice mine when its running, not what I'd call noisy, maybe a paving slab underneath?

Posted : 02/05/2021 11:13 pm
adi_pen
(@adi_pen)
New Member

@jirohp

The way I solved it was that I had to increase the speed of the print to 125% for it to print. That’s the only way I can get prusament to print, I think they have a higher melt temp than other PLA, but who knows ¯\_(ツ)_/¯  

Posted : 03/05/2021 12:00 am
JirohP
(@jirohp)
Active Member

@lize

I heard about the paving slab idea, but the one I have would probably crush the cabinet, if  I could even loft it that high😆

I will look at reducing vibration though. Thanks

Posted : 03/05/2021 8:11 am
JirohP
(@jirohp)
Active Member

If you think it needs more heat, why did you increase the print speed instead?  Sorry, I have had my machine for a while and not been very adventurous with it, but my daughter has just started using fusion at uni and wants to print everything... I suddenly need to understand how the printer behaves so I can problem solve her stuff. 

If you change the speed not the heat doesn't that give the PLA less time to heat up? Do you change the settings in slicer or on the machine?

I need to start to experiment🤔

Posted : 03/05/2021 8:17 am
JoanTabb
(@joantabb)
Moderator

@jirohp

sometimes experimenting is good...  You may get answers faster than the forum can give them... 

3D printing normally has a broad spectrum of printable combinations, where prints succeed but have lesser or greater quality.... 

A frient set My first printer to print the gear bearing model at ABS temperatures, which were a bit high for the PLA Filament that she used... 

the bottom layers were nasty, but the model improved a little as it moved away from the build plate....

when complete I was amazed that the gears still rotated despite the distortion... 

one thing to be aware of, if you have had other manufacturers printers, is that the Prusa Mk1, Mk2 and Mk3 series printers all have direct drive extruders and you don't need a lot of retraction. in fact large retraction values can cause blockages. the Prusa default retraction for these printers, is 0.8mm,   I tend to run mine at 0.4mm retraction and get good prints. 

the temperature sensors (Thermistors) on your printer are amazing for what they cost and how they generally perform, but they are sensors, not thermometers, so the temperature reported may not be correct.   try different temperatures, see what differences you get.

if your temperature is too low, the extruder tends to have problems extruding, if the temperature is too high the printer often causes strings between different parts of the model. see the image below.     this white filament  was very stringy at any temperature above 170C. unfortunately at 170C and below the Prusa Printers disable the extruder motor, (Unless you send a Gcode command to reset the cold extrusion temperature) which is what I eventually did with this filament

You can see some of the strings on the red sections. and this was after using a hot air blower to make the strings shrivel up!

My 3DQF PLA filament likes to print hot  in fact the manufacturer comments on this on the packaging. 

Have a play, try different temperatures, try different retraction settings...  and different speeds, see what happens. 
Every printer is a little different... even two of the same printers built by the same person, will perform slightly differently. 

For information a temperature tower test print, normally starts hot and work towards cool temperatures, to ensure that the printer starts to print... then if it reaches a temperature where it struggles to print, you know what's going on... 

regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK...
Posted : 03/05/2021 11:05 am
JirohP
(@jirohp)
Active Member
I've never hard the time or the incentive to experiment before, but I have just had to resign for medical reasons and there is no way she is going to know more about my printer than me.

I have time and incentive now...
Posted : 03/05/2021 12:02 pm
cwbullet
(@cwbullet)
Illustrious Member

@jirohp

Good luck.  I am retiring soon and will be in a similar situation.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 08/05/2021 2:28 am
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 --
(@)
Illustrious Member
Posted by: @jirohp

If you think it needs more heat, why did you increase the print speed instead?  Sorry, I have had my machine for a while and not been very adventurous with it, but my daughter has just started using fusion at uni and wants to print everything... I suddenly need to understand how the printer behaves so I can problem solve her stuff. 

If you change the speed not the heat doesn't that give the PLA less time to heat up? Do you change the settings in slicer or on the machine?

I need to start to experiment🤔

My theory on why speeding up the print works is that the pumping action of retractions pushes hot filament up into the heat break (standard fluid dynamics). When the filament isn't moving fast, the melt can cool enough to solidify into a plug that is a friction fit in the heat break. Adding speed allows less melt to flow backwards since it is being pushed through the nozzle faster. A thermal balancing act: too much heat and too little flow means clogs; just enough heat and just enough flow, works.  Heck, perhaps lowering the nozzle temp might work as well.

 

Posted : 08/05/2021 5:10 am
cwbullet
(@cwbullet)
Illustrious Member

@tim-2

Interesting theory.  I will try speeding my prints up during the need for retraction.  

--------------------
Chuck H
3D Printer Review Blog...
Posted : 08/05/2021 12:51 pm
JirohP
(@jirohp)
Active Member

This all sounds very technical, I think I will start with some basic test prints and learn how to use slicer properly. That way I might be able to learn a bit more about the feed rate, retraction speeds etc.

I have taken the top off the cabinet, and everything has printed properly since, but I haven't tried any long prints yet.

Maybe I'll have another go at the pumpkin headed horseman I tried the other day. Not my design.

Posted : 08/05/2021 1:05 pm
adi_pen
(@adi_pen)
New Member

@jirohp

Sorry for taking so long to reply, Speeding it up allows for better flow of the filament and in turn doesn't allow for heat creep. The problem currently is that the Prusament PLA I have suffers from an insane amount of heat creep. The less time the filament stays in the heating element, the less likely it is to suffer from this phenomenon. I used to slice everything to normal settings and then just increase the speed on the printer!

Hope this helps!

Posted : 14/05/2021 2:35 pm
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