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How can I get my printer to work again.  

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tre4b
(@tre4b)
Trusted Member
How can I get my printer to work again.

 

My printer has always been reliable and produced good prints with no effort.  I bought a MMU3 upgrade kit and that needed me to change from a 0.6 to a 0.4 nozzle.  I managed to break the heater and had to replace it, and combined it with a few other issues but now it is printing okay.  Except for one thing.  It keeps having a crash detection and starting again.  I tried turning crash detection off and the below was the resulting print, which I stopped before the bad escalated too far.

I've never had a problem printing PETG and I have always had crash detection switched on but never had any crashes occur.  I've done everything I can think of from temperature towers for the filament to checking for obstructions.  I think the crash detections are happening because occasionally an oozing happens and the nozzle hits it.  I have tried dialing retraction up to 3.5 I have tried speeding up the retraction and always with this happening somewhere.  I've been cleaning the nozzle before each print and I have run some cleaner filament through.  The first two or three layers are always good without issue, this always starts at about 5mm up from the bed.  I have calibrated again for squareness.

I am now out of ideas so thought it was time to ask here and see if anyone has any suggestions.  The above print was done with brand new prusament from the MMU3 kit so I think the filament should be fine.

This topic was modified 1 month ago by tre4b
Posted : 12/04/2024 1:34 pm
Eef
 Eef
(@eef)
Estimable Member
RE: How can I get my printer to work again.

Is it warping in the middle? Or just a matter of shade falling there? 

Seems a big blob caused that crash. Blob is (as far I know) the result of processing to much material, then there is place for. 
Having your other messages in mind, I know you must have cleaned very well, before this print. 
So what makes it produces too much?? 
Would calibrating E-steps make a difference? 
(As you see beyond my knowledge, but thinking aloud) 

And maybe not enough Z-heigth when hopping to other spots on the print?

Posted : 12/04/2024 2:23 pm
tre4b
(@tre4b)
Trusted Member
Topic starter answered:
RE: How can I get my printer to work again.

Yeah it is big blobs happening in various places. 

I've tried extrusion calibrating and all was fine.  I  tried increasing the z when hopping but it still crashed against the blobs.  I thought initially it was the filament, which is why I decided to open the new one.  It's so strange, I can normally iron these things out but I've not had a good print from the printer in over a week now.

Posted : 12/04/2024 2:40 pm
Eef
 Eef
(@eef)
Estimable Member
RE: How can I get my printer to work again.

Searching a bit in PrusaSlicer if there could be conflicting parameters: 
- nozzle size (I suppose 0.4?)
- extrusion multiplier (in my printer 1.1) but definitely has effect on more/less material 
- It is PETG, what about temp? It should flow of the nozzle (not pushed as with PLA). Higher temp make it flow and merge better with last layer. (and if it sticks better is will blob less 🙂 
- And directly connected, what about cooling? From: https://help.prusa3d.com/article/petg_2059  
"Unlike PLA, PETG requires a heated bed (85 °C). Its bridging- and overhang-behavior is usually worse, plus it is prone to stringing. Stringing can be moderated with higher retractions and lower nozzle temperature, but we suggest using the PrusaSlicer profiles that should work fine. It’s important to cool the PETG print - this helps to keep the model detailed and prevents stringing and oozing. But if you want the model to be as tough as possible, try to turn off the print fan. Higher filament temperature improves merging between layers which leads to better mechanical resistance. Otherwise, we recommend printing the first few layers with the print fan off to prevent deformation, then with the fan running at half its power." 

I would start with the temp/cooling first. You did a lot of rebuilding, so maybe the cooling is improved, etcetera. 

Posted : 12/04/2024 3:10 pm
Diem
 Diem
(@diem)
Illustrious Member

Please show us the hotend/nozzle assembly from two different angles.

Cheerio,

Posted : 12/04/2024 4:36 pm
tre4b
(@tre4b)
Trusted Member
Topic starter answered:
RE: How can I get my printer to work again.

Here you go,  that drip on the nozzle appears after any print finishes.  Sometimes it is 40-50mm so that is quite a short one.

 

Posted : 13/04/2024 3:14 pm
Diem
 Diem
(@diem)
Illustrious Member

Not as informative as I'd hoped (you need to clean your fan BTW).

You may need to remove the sock to check, it blocks the photos: Is there melted filament running down from the top of the heatblock?

Cheerio,

Posted : 13/04/2024 4:39 pm
tre4b
(@tre4b)
Trusted Member
Topic starter answered:
RE: How can I get my printer to work again.

Not any more.  The second time I took it apart was because I saw it was leaking from the top end of the heat break.  I was super nervous about it because of breaking the original heater cable so had not tightened the nozzle enough when it was hot.  There is none now though.

Do you know I had never noticed the dust in that fan in the real world so didn't look at the fan.  Will be vacuuming that now....

Posted : 15/04/2024 6:32 pm
tre4b
(@tre4b)
Trusted Member
Topic starter answered:
RE: How can I get my printer to work again.

 

Well feck me!!!

Thought I would check the ruddy thing and look what I found....  Annoying beyond belief that this happened again.  You can see this was from when I was initially trying to print in prusa orange before changing to the new black.   I will get this resolved and try again.  And I'm leaving the flipping sock of until it is working solidly again.

 

Posted : 15/04/2024 6:40 pm
Diem
 Diem
(@diem)
Illustrious Member

so didn't look at the fan. Will be vacuuming that now....

I find a stiffish atist's paintbrush is the best tool.

I will get this resolved and try again.

Pay particular attention to the diagrams at the bottom of this page:

https://help.prusa3d.com/en/article/changing-or-replacing-the-nozzle-mk2-5s-mk3s-mk3s_2069

Make sure you have genuine E3D nozzles, there are lots of cheap 'clones' around that are a fraction short in the thread.

Cheerio,

Posted : 15/04/2024 10:30 pm
tre4b
(@tre4b)
Trusted Member
Topic starter answered:
RE: How can I get my printer to work again.

I'm using NozzleX nozzles which I got from E3D.

I think what happened was when I cleaned up the block I inadvertently left some melted plastic in the threads of the block.  When I had put the nozzle together this probably compressed to leave a gap that caused another leak.  I noticed trying to run a volcano nozzle all the way through it stopped in the middle, so I heated the block and ran a tap through it until it was smooth and clean.  I just produced a perfect calibration cube so I am hopeful that a full print will work now so will try that later.

I've long been thinking of replacing the head with a revo one or something.  Then the Mk4 came out so I've been tossing up whether to do the upgrade or wait and see if they come out with a Mk3 size CoreXY at some point 😉    Thanks so much for the help.

Posted : 17/04/2024 7:48 am
Diem
 Diem
(@diem)
Illustrious Member

They already have 'though not for the hobbyist market:

https://blog.prusa3d.com/the-future-of-manufacturing-by-prusa-research_55993/

Cheerio,

Posted : 17/04/2024 9:32 am
tre4b liked
tre4b
(@tre4b)
Trusted Member
Topic starter answered:
RE: How can I get my printer to work again.

Yeah I'd seen them, I'm hoping they will realise quite a few people are looking at moving away from bed slingers.  I really don't want to move to the X1Carbon or similar.  I like Prusas views on open source and am willing to put money where my mouth is.  It's just the XL is so much more than I would really make use of, even though I do toss up going for it 😉

Good and bad news on the print though.  It just finished and the part is serviceable, but I still got different colour filament embedded in the print from somewhere.  I am assuming again from a collision or it dripping from somewhere.

I will double check the join later just in case it is still not right!

Posted : 17/04/2024 10:58 am
tre4b
(@tre4b)
Trusted Member
Topic starter answered:
RE: How can I get my printer to work again.

 

Now that is strange.  Do you know what it means by power failures?  As far as I know there were none, nor did anything appear to happen with the filament.  I print via octoprint so maybe something to do with that?

Posted : 17/04/2024 11:02 am
Diem
 Diem
(@diem)
Illustrious Member

Is the power connection loose?

Check the underside of the print, are you still getting warping?  - if so those crashes might be genuine ... if unsure show us the underside and maybe we'll address this as a warping issue.

Otherwise, to rule out several common causes of false crashes run through:

  https://help.prusa3d.com/en/article/i3-printers-regular-maintenance_2072

  https://help.prusa3d.com/guide/maintenance-tips_23200

Then, if they continue, come back and we'll work through the less common possibilities.

Cheerio,

Posted : 17/04/2024 7:00 pm
tre4b
(@tre4b)
Trusted Member
Topic starter answered:
RE: How can I get my printer to work again.

Well the good news is it is now working perfectly, just turned out a perfect quality print and starting on another now.  The issue above was, believe it or not, the same leakage thing AGAIN.   I had put the whole hot end back together before putting it back in the extruder thinking I had tightened it up (was using an external heater to heat the block etc to clean it so I just used the same to preheat for putting the nozzle back in).  I'd forgotten I could not get enough purchase to tighten it an meant to do it when back in the printer.  I have done that now and it is working properly without leakage.

So two weeks of problem prints all relating to my own stuff ups along the way, from breaking the heater cable to not tightening up the nozzle enough.  Definitely must be getting old.  Thank you so much for your help @Diem.   

Posted : 19/04/2024 7:46 am
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