Under and Over Extruding - Now no longer extruding at all. Please help
 
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Under and Over Extruding - Now no longer extruding at all. Please help  

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Jemma
(@jemma)
New Member
Under and Over Extruding - Now no longer extruding at all. Please help

Hello, I really hope you can help me!  

I have x3 Prusa Mini's which I received in Sep 20.  I have been using Yoyi Silk Green PLA 1.75mm filament since I got them as this is the colour of my company's brand.  I bought the Prusa Mini's after running x5 Ender 3 Pro's for several months but I've had massive issues with warping so I decided to buy the Prusa Mini's instead and have never looked back!  However, about 10 days ago, one of the Mini's stopped extruding halfway through a 2hr print (and halfway through a reel).  I couldn't figure out what was wrong and no matter what I tried, it just wouldn't print.  Then about 5 days ago another Mini started with the same issue.  It either under/over extrudes like in the photo in a stripy pattern, or it just doesn't extrude at all.  The gears are turning in the extruder but the filament isn't moving at all (the printer carries on as though it is printing).  I have cleaned out the nozzle, done a cold pull through the hot bed and I've cleaned out the extruder/gears (multiple times) but nothing seems to fix the issue.  As a way of eliminating all possibilities, I tried a different filament (the free Prusament sample that came with the Mini's) and the problem goes away. 🙄   I have contacted a local UK based filament manufacturing company to have the colour I use colour matched (as Prusa don't do anything similar) and I tried their sample and.... you guessed it...!  It sometimes extrudes, it sometimes doesn't.  I honestly don't know what to do.  They have Prusa's and Ender's etc that they test their filament on and they even track the +- deviation of the filament per spool which you can track like you can do with the Prusament.  Is my machine now too sensitive for some reason?

Has anyone ever seen anything like this before?  Do you think it would help if I somehow managed to change the gears in the extruder?  Why would this start happening after months of absolutely no issues whatsoever?  Could there be something else that's causing this that I've not thought of?  

I now have only 1 working Prusa Mini and I'm dreading having to change the reel.  If I knew of somewhere local that I could take it to (covid permitting) or something such as a service centre in the UK that I could send them to then I would, as production of my products has almost ground to a halt.  

If you have any thoughts, advice or if you have seen this before then I would really appreciate your help.

Thanks

Jemma x

 

Posted : 17/03/2021 1:05 pm
MadCyborg
(@madcyborg)
Eminent Member
RE: Under and Over Extruding - Now no longer extruding at all. Please help

If the filament diameter is consistent, and the extruder gear is turning consistently and in it's correct place (not wobbling or anything like that), then something else must prevent even transport of the filament. Do have an eye on the extruder temp? I think it's unlikely, but if it fluctuates very badly (+- 15 K or more), maybe this could happen?
What kind of spool holder do you use? Is it sitting next to the printer, or does the filament come through any longer way and maybe some ptfe tubes?
I'd also try to test, if the extruder transports the correct amount of filament. I like to do this through making a cube in Prusa Slicer, put in vase mode and scaling it, until it uses exactly 1 m of filament. I then measure and mark 1 m on the loaded filament, start the print and see, if it realy pulls 1 m.

Posted : 17/03/2021 4:29 pm
Diem
 Diem
(@diem)
Prominent Member
RE: Under and Over Extruding - Now no longer extruding at all. Please help

Two printers using the same filament suddenly develop the same problem but a change of filament works OK?

This does read like a filament problem.

As a second check open a fresh roll of your usual filament and test print with that.

Here's what I suspect but please note I am using i3Mk3.

I note you too are in the UK.  We have just had a run of unusually warm, for the time of year, very wet weather.  If you are like me you have used much less heating and your atmospheric humidity levels have risen.  I have just started having moisture problems with filaments left open to the air; about six weeks earlier than expected.

I haven't had a print actually fail but aIui the Mini seems a bit more sensitive to moist filament.

As correlation you might have heard fizzing and popping noises at the extruder 'though it's easy to miss them.  There may have had more stringing than usual or slight pitting on smooth surfaces.

Look for threads on here about filament drying - try a spell in an electric oven, it's not ideal but it is the quick and dirty way to test if a more sophisticated method is worth adopting.

The substitute filament you have commisioned with intermittent results is a seperate issue.  It's unlikely to be damp (yet) but a custom filament will not be in the slicer presets and you will have to create your own profile to suit it.

Your picture is not quite clear enough to be sure; your first layer is suspect: if it is like that with dry filament you may need to recalibrate.

Do you think it would help if I somehow managed to change the gears in the extruder?

By now they are probably full of filament debris, they will need cleaning.

Hth, Cheerio,

Posted : 18/03/2021 7:19 am
Jemma
(@jemma)
New Member
Topic starter answered:
RE: Under and Over Extruding - Now no longer extruding at all. Please help

Thank you so much to both of you.  I have tried to dry out the filament and I have now got one printer working so it seems it was a moisture issue after all.  I'll try the 2nd printer tomorrow and see if that one works too.

Again, thank you so much for your help, I am so very grateful!!!

Thanks

Jemma x

 

 

Posted : 18/03/2021 9:55 pm
EPICOREOz
(@epicoreoz)
Active Member
RE: Under and Over Extruding - Now no longer extruding at all. Please help

I am having the same issues.
Had my mini 2 weeks and had amazing prints then changed the filament and it crapped out.

Extruder gear turns but will not catch the filament, I have tried 3 different brands of PLA all 1.75.
The nozzle is clean and clear, all ptfe is clear of obstructions, If I take the extruder apart and feed filament through by hand it catches and spins the gear. Im using the spool holder that came with my mini.

I have contacted Prusa about this and they are sending new printed extruder parts hoping that its the issues, but im not so sure its the extruder parts.
Also I dont have a moisture/dry issue.

Posted : 21/03/2021 8:44 pm
Diem
 Diem
(@diem)
Prominent Member
RE: Under and Over Extruding - Now no longer extruding at all. Please help

@epicoreoz

If you initially overtightened the extruder idler you *might* have distorted something...

Have you measured the diameter of the new filament?  It's unusual to find it these days but if it is a little thinner than spec it becomes hard to grip.

Cheerio,

Posted : 22/03/2021 4:01 am
EPICOREOz
(@epicoreoz)
Active Member
RE: Under and Over Extruding - Now no longer extruding at all. Please help

@diem

I have not overtightened anything. And its not the filament. I have tested 3 spools with it since it stopped working. 2 were the same brand as what I used on the machine before with no issues.

Posted : 22/03/2021 1:53 pm
Jemma
(@jemma)
New Member
Topic starter answered:
RE: Under and Over Extruding - Now no longer extruding at all. Please help

Well one of my printers is now working (fingers crossed!) and the other was working for a day but now it's not working again so that's 1 day working out of 2 weeks 🙁  I've tried drying out the filament, we have bought a dehumidifier and a humidity detector and both should be delivered this week.  I'm quite honestly fed up and I don't know whether to contact Prusa for help?  Does anyone know if the Mini's are particularly sensitive?  I'm using the exact same filament on my x5 Ender 3 Pro's and I've had no problems whatsoever!   

Posted : 22/03/2021 5:29 pm
Diem
 Diem
(@diem)
Prominent Member
RE: Under and Over Extruding - Now no longer extruding at all. Please help

@jemma

Is it possible you dried the outer layers of fiament and then printed those layers - so now you are printing damp filament again?

This is one drawback of oven drying, it drives the moisture in both directions.

Also there might be a slight change in surface character, gently tweaking the extruder idler pressure might help.

I don't know whether to contact Prusa for help

The best way is to log into your shop account, go to support and use Chat - bottom right in most browsers.

Cheerio,

Posted : 22/03/2021 11:43 pm
Diem
 Diem
(@diem)
Prominent Member
RE: Under and Over Extruding - Now no longer extruding at all. Please help
Posted by: @epicoreoz

@diem

I have not overtightened anything.

Granted, that would be unusual.

And its not the filament. I have tested 3 spools with it since it stopped working. 2 were the same brand as what I used on the machine before with no issues.

The same brand does not mean the same batch.

OK.

Loosen off the extruder idler, clean the teeth, trim the end of the filament, check for obvious hot end blockages.

Then tighten the idler one turn at a time and retry the load until you get some grip.

If you never get true grip but the gears turn and grind filament without feeding then check the filament path is straight and maybe try a cold pull.

Hth, Cheerio,

Posted : 23/03/2021 12:05 am
EPICOREOz
(@epicoreoz)
Active Member
RE: Under and Over Extruding - Now no longer extruding at all. Please help

@diem

Been there done that.... no luck

Posted : 23/03/2021 1:10 am
Diem
 Diem
(@diem)
Prominent Member
RE: Under and Over Extruding - Now no longer extruding at all. Please help

@epicoreoz

If you never get any grip, or If you never get true grip but the gears turn and grind filament without feeding then take a close look at the filament path, it reads as if something is not straight.

Cheerio,

Posted : 23/03/2021 4:32 am
HU3E
 HU3E
(@hu3e)
Active Member
RE: Under and Over Extruding - Now no longer extruding at all. Please help

Im new to 3D printing and I’ve run into some problems. When I first got the printer everything was printing fine up until four weeks after when it stopped printing halfway through a print. When I unloaded it the filament had grooves in it from where the extruder chipped away at it. After seeing that I clean the extruder I raised the heat break and also replaced the nozzle and nothing works it can’t even get a first layer down without it getting chewed up. The weird thing is I can load and unload it and also purge and everything seems fine it only happens when I print.

Posted : 30/03/2021 4:35 pm
JoanTabb
(@joantabb)
Moderator
RE: Under and Over Extruding - Now no longer extruding at all. Please help

@hu3e

I don't have a mini... so guessing... 

have you tried a Prusa gcode since this problem happened? 

Whilst not paying attention a while ago, I sliced a model printed and it seemed to be over extruding, so I went back into slicer, reset the extrusion multiplier and re sliced the model... 
when I reprinted on My Mk3S, the Prime line was no longer a little thick, it was like a slug on the edge of My build plate, and the skirt line was like wholemeal spaghetti, much thicker than expected and a bit rough on the surface... 

Turns out that instead of re setting from extrusion multiplier 1 to extrusion multiplier 0.9.... I had set it to 9.0 anf the slicer had swallowed the stupid entry, so my printer was trying to provide 9 times the previously over extruded amount... 

I escalated this with Prusa, and the more recent versions of slicer now question large Extrusion multipliers... 

but long story short... the issue may be in slicer, not your printer, and reverting to a Prusa prepared, pre sliced model, may show if that is the case... 

P.S. check that you have the latest Prusa Driver download, which includes the latest Slicer version.

Good luck, Happy Printing.
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 : 30/03/2021 8:15 pm
HU3E
 HU3E
(@hu3e)
Active Member
RE: Under and Over Extruding - Now no longer extruding at all. Please help

@joantabb

Thank you so much.🙏🙏

Posted : 01/04/2021 5:15 am
HU3E
 HU3E
(@hu3e)
Active Member
RE: Under and Over Extruding - Now no longer extruding at all. Please help

This is what all my prints look like and i really need some advice on was too do.

Posted : 05/04/2021 5:28 am
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