Oozing, burning, and layer shifting  

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JustinianIII
(@the-_dude)
Active Member

I replaced a nozzle on my MK3S. I started getting some serious oozing all over my everything and some of it was burnt and would fall off into my prints as burned plastic blobs. I figured out after some reading that my new nozzles weren't matching up with the heat sink tube inside the head. At this point my stuff was a complete mess and I had broken my thermo wires trying to get things apart so I ordered brand new E3D parts. Got everything assembled and I reset my printer to rerun the wizard. The first 24 hours of printing was awesome. Then the first long print that I attempted (7 hrs), returned some layer shifting at the higher levels and I noticed that my white PLA filament had those nasty brown burned blobs in my print again. After looking at the nozzle, I see that the filament is once again oozing out. I'm not sure where to start on this one. When assembling my new print head, I put the nozzle in first, then the heat sink tube went in next to assure it was matching inside. Is there a magical sealant that I was supposed to apply that I didn't? Neither the previous nor the new setup had clogged nozzles or clogged pfte tubes. 

 

As for the layer shifting at higher levels, I'm assuming this is a different issue, but noted it here just in case albeit my belt tension stats are saying that they are in the sweet spot, I'll get some grease in it soon because my right Z motor is making a chirping noise which I am figuring is causing friction at just the height I'm seeing layer shifting in.

Posted : 13/07/2019 1:04 pm
JustinianIII
(@the-_dude)
Active Member

Oh. And I'm using ESUN PLA Pro + white filament. And my printer is in a spare bedroom that has it's own A/C unit that I keep set to 22C.

Posted : 13/07/2019 1:12 pm
JustinianIII
(@the-_dude)
Active Member

Posted : 13/07/2019 1:17 pm
Tim
(@tim-m30)
Illustrious Member

Common problem here is when replacing the nozzle folk don't follow the E3D instructions and end up tightening the nozzle to the heater block rather than against the heat break. This leaves a loose heat break and gap where plastic oozes past the threads and all over your parts.

Step 1 is everything is done at temperature (280c) - step two is keeping the HEX away from the heater block (1/4 turn loose).

https://e3d-online.dozuki.com/Guide/Changing+Nozzles/45

https://e3d-online.dozuki.com/Guide/V6+Assembly/6

This post was modified 1 year ago 2 times by Tim
It is always wise to get more than one opinion......
Posted : 14/07/2019 12:19 am
JustinianIII
(@the-_dude)
Active Member

If I'm building a new setup from scratch and everything is brand new, why would I heat it up to 280? And what difference does it make if I tighten the nozzle to the heat break or the heat break to the nozzle? Maybe I didn't make it clear enough in my original post and I apologize for that, but we're talking a brand new build on this and while my nozzle isn't sticking out away from the heater block as in your picture, I did thread the heat break into the heater block to fit tight up against the nozzle. I guess I must be missing something, because your reply makes no sense mechanically as to why doing it this way exactly is any different than how I did it and why I'm still having the oozing problem. 

 

Now on a different note, after doing some other reading I started looking at my settings in my slicer. In particular my retraction settings. While, yes, I do have a gap or something happening internally, I believe I've found that because I went from a .4 to a .25 nozzle, there was a lot more plastic being pushed to the nozzle than could actually fit. So I adjusted some retraction settings and followed a few youtub vids to get my brain wrapped around some of the theory here which makes sense. And while I still have some plastic oozing over the sides, it has now slowed to a crawl and I'm printing near normal again. Once I rip open the heat block and play around with the heat break and nozzle adjustments some more, this will hopefully be solved. 

Posted : 14/07/2019 8:39 pm
Tim
(@tim-m30)
Illustrious Member

Okay - if the fact E3D - who makes the parts - is very explicit on how to assemble the V6 hot end and says to not torque/bury the nozzle into the heater block and heat everything to 285c to tighten isn't enough reason.  And folk who ignore the E3D instructions have leaks. Not much else I can say.

This post was modified 1 year ago by Tim
It is always wise to get more than one opinion......
Posted : 14/07/2019 9:00 pm
david.a66
(@david-a66)
Honorable Member

the heat block expands when heated, what was a tight connection at room temp is now loose and leaky.  have a look at either the e3d or prusa plant tour youtube videos and they both show the hotend assembly /test stations and the requirement for final torque of the nozzle at 280C. the only hood procedure is .. install nozzle and back out 1/4 turn, install heatbreak till tight against nozzle, install heatsink and  ptfe, install in printer and power on and heat to 280C. while at 280C torque nozzle to final position

Posted : 14/07/2019 10:39 pm
JustinianIII and Tim liked
JustinianIII
(@the-_dude)
Active Member
Posted by: Tim

Okay - if the fact E3D - who makes the parts - is very explicit on how to assemble the V6 hot end and says to not torque/bury the nozzle into the heater block and heat everything to 285c to tighten isn't enough reason.  And folk who ignore the E3D instructions have leaks. Not much else I can say.

First off, thank you David.

 

To Tim,

 

Uppity answers like this are why people avoid the internet. I wasn't being argumentative, I was asking for an actual answer and not just some cut and pasted, 2 cent company line. Now that David explained a little more it makes sense. How can someone learn their printer if all you spout is accusations from the get? I was looking for an answer as to how my printer works, not some 2 bit link and a shitty attitude. I came here because this is the OEM site and figured there'd be a welcome reception to people learning things. So I fucked up.. it's my printer and my money. If you didn't want to give an actual answer and help someone while being a decent human being, you could have just as easily not typed a response and went about your day kicking puppies, raping goats, and eating cats. Anyway.. consider this solved and no need to respond as I'll be deleting my account from here if this is the type of answers I can expect from a "famed" member. 

Posted : 15/07/2019 12:06 am
Tim
(@tim-m30)
Illustrious Member
Posted by: JustinianIII
Posted by: Tim
Common problem here is when replacing the nozzle folk don't follow the E3D instructions and end up tightening the nozzle to the heater block rather than against the heat break. This leaves a loose heat break and gap where plastic oozes past the threads and all over your parts.

First off, thank you David.

 

To Tim,

 

Uppity answers like this are why people avoid the internet. I wasn't being argumentative, I was asking for an actual answer and not just some cut and pasted, 2 cent company line. Now that David explained a little more it makes sense. How can someone learn their printer if all you spout is accusations from the get? I was looking for an answer as to how my printer works, not some 2 bit link and a shitty attitude. I came here because this is the OEM site and figured there'd be a welcome reception to people learning things. So I fucked up.. it's my printer and my money. If you didn't want to give an actual answer and help someone while being a decent human being, you could have just as easily not typed a response and went about your day kicking puppies, raping goats, and eating cats. Anyway.. consider this solved and no need to respond as I'll be deleting my account from here if this is the type of answers I can expect from a "famed" member. 

I guess my stating the reason to follow the manufacturers instructions is to avoid a leaking hot end isn't good enough.   I wonder if someone telling you that changing the oil in your car per mfg recommendations is a good idea is also an affront if they don't also explain why metal - metal contact is a problem.

See ya.

ps: My apologies if I offended.  That wasn't my goal.

This post was modified 1 year ago by Tim
It is always wise to get more than one opinion......
Posted : 15/07/2019 12:52 am
bobstro
(@bobstro)
Illustrious Member
Posted by: JustinianIII

If I'm building a new setup from scratch and everything is brand new, why would I heat it up to 280? [...]

Just a bit of expansion: I've read that the heater block will expand more than the typical nozzle, so the high temp ensures everything tightens back up with a good seal. This mirrors my experience, so I'm not going to change anything.

[...] And while I still have some plastic oozing over the sides, it has now slowed to a crawl and I'm printing near normal again. Once I rip open the heat block and play around with the heat break and nozzle adjustments some more, this will hopefully be solved. 

Be prepared for a bit of internal cleanup when you do next remove a nozzle. With any luck, it'll clean out easily. Just be sure to get it out or you'll be stuck with that oozing and flaky nozzle fit.

I've put notes on setting up PrusaSlicer (formerly Slic3rPE) profiles with different nozzle sizes here. It's unfortunately you're running into some speed bumps, but keep with it. A lot of great opportunities open up when you start playing with nozzles.

This post was modified 1 year ago by bobstro
My notes and disclaimers on 3D printing and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan...
Posted : 15/07/2019 1:54 am
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