Issues with PETG on brand-new mini+ (preassembled)  

issues again

After 14 hours of print I got clog just before print finished (:/).

I honestly don't know what is happening. In this case, as well as others I tried to do a cold pull, but I and having issues pushing filament straight to hotend. It seems to get stuck somewhere inside tube, I'm going to dissasemble whole thing again.

I can't for example push filament from top (with 280C), unless it has super sharp edge. Pushing needle from below is smooth and filament comes out on needle.

I'll see if this could be because I didn't chamfer ptfe tube, I got plastic guides from Bondtech page now so I'll redo this.

Any other ideas what could be happening here? I am really frustrated as it is supposed to be a printer in which you shouldn't tinker much..

Chewed

It looks like it chewed up the filament.  That is your clicking.  You either bad/wet filament or your tension screw is too tight.

I am really frustrated as it is supposed to be a printer in which you shouldn't tinker much..

Which is what I found it to be, with two exceptions:

1. Filament gets chewed up easily, and adjusting the idler screw gets old quickly. The Bondtech dual drive extruder to the rescue. $35 for the Trianglelab clone. No more problems.

2. It's easy to get an xz skew, in particular the way the belt tightening method works. But with some attention to detail, following the knowledgebase article on xz skew correction, it's an easy fix.

Posted by: @cwbullet

It looks like it chewed up the filament.  That is your clicking.  You either bad/wet filament or your tension screw is too tight.

You would think, but it only clicks on change of direction and I verified that when I had extruder dissasembled, gears are teoretically touching, but when I rotated one gear it had a bit of slack before it engaged. You can hear and see when it happens:

https://photos.app.goo.gl/mYSw9agBsBrpkBmi8

I noticed strange thing - underextrusion on higher layers

Flow factor is set to 95 - I changed it mid print to 97 on smaller test and I'll see how it goes.

As for filament, it's brand new Prusament PETG (arrived yesterday).

Oh, I reassembled hotend with new ptfe tube chamfered from both sides, intentionally a bit longer (37mm) so that for sure it is compressed from both sides.

At every clog in last few days I noticed small bump inside heatbreak on whole circuit, like it was flowing to very tiny gap (<0.1mm), will see how it goes now..

I'm up to the point where I'm afraid of leaving this print for longer than several minutes, which is frustrating knowing I have a bunch of interesting projects each for several hours of printing..

Dry the filamentg

Have you tried drying the filament?  It does not matter that it is a new roll.  

Posted by: @cwbullet

Have you tried drying the filament?  It does not matter that it is a new roll.  

I didn't. I will do that today to see if it helps. If this is it, what's the point of Prusa guys to have those spool shipped in vacuumed bag? Makes me mad :/

Previous print went flawless for 7 hours. Same spool, print started pretty much right after, humidity in room around 60%. 14 hours (not even, I could see bad layers in the evening (when it was toughly 3 hours in). So that would mean that I can't print more than 10 hours straight? This is insane.

Never seen this before but this summer I had significant issues with one type of prusament,  neon green PETG. Out of the dryer box it worked great in the morning. By the evening insane stringing and zits. 
You may want to try printing from a dry box but I'm not convinced it's wet filament in your case. 

Hydration

Hydration of filament is not just a Prusa issue.  I have had this with almost all makers that I commonly use.  I have come to expect it from time to time.  

Posted by: @cantchoose

 

Posted by: @cwbullet

Have you tried drying the filament?  It does not matter that it is a new roll.  

I didn't. I will do that today to see if it helps. If this is it, what's the point of Prusa guys to have those spool shipped in vacuumed bag? Makes me mad :/

Previous print went flawless for 7 hours. Same spool, print started pretty much right after, humidity in room around 60%. 14 hours (not even, I could see bad layers in the evening (when it was toughly 3 hours in). So that would mean that I can't print more than 10 hours straight? This is insane.

Mad?

Posted by: @cantchoose

 [...] I didn't. I will do that today to see if it helps. If this is it, what's the point of Prusa guys to have those spool shipped in vacuumed bag? Makes me mad :/

Not sure I understand why it would make you mad. If you're painting your house, you have to take care of the paint and clean the brushes. The bag is to improve the odds of the filament get to you without degradation. Too much exposure will make some filament completely unusable. The seal may not always be perfect, but the filament should be usable out of the box. Once you open the seal, if environmental conditions are right in your location and depending on the filament, a few days may be all that's required to experience problems (including with PLA). Any artist or builder has to take care of their materials.

RE: Issues with PETG on brand-new mini+ (preassembled)

Once you open the seal, if environmental conditions are right in your location and depending on the filament, a few days may be all that's required to experience problems (including with PLA). Any artist or builder has to take care of their materials.

Fully agree. I specifically wrote that my last filament was brand new - opened box and started printing.

Anyway, after replacing ptfe tube I didn't get clogs so far (13 hours). I also baked this filament and indeed it reflected in less stringing and better surfaces, which could be that brand-new filament was already too wet.

Going forward I will get myself a filament dryer, and pre-bake all new spools as pre-caution. It's dumb (I can't figure out any other material sold to customers that is essentially broken before opened, yet acceptable by buyers), but if this solves my problems, I will do it with grim on my face.

Filament dryer

Posted by: @cantchoose

Anyway, after replacing ptfe tube I didn't get clogs so far (13 hours)...

I'm glad you made it! -let's hope it will stay that way for a while 🤗 

About filament dryer... Before deciding, I recommend you to watch this video (6 most popular dryer tested).
I'm using food dryer, because it's cheaper and more effective, but one can't print and dry at the same time -so pick what suits your needs best.

End of print was unfortunately quite bad, with next print (straight after cleaning sheet) having problem even to finish first layer (partial clogs). I didn't print over night, filament got baked for 4 hour in morning and now 1 hour in it prints good again. All the time now printer is in other room, radiator is fairly hot with low moisture in air. Seems that filament out of the box is just too wet to print, which checks out that next print was bad on start (enough filament was used to unravel lower layers on spool). I'm gonna research good dryer. It sucks that even after baking for few hours, I can't print more than what, 7-8 hours before filament degrades. It's supposed to be premium filament.. It's so far really bad experience and I can't help but think that I could get away with chinese printer for 1/3 of this price to tinker same amount and have moisture issues on brand new filaments. 

I was thinking about double gear bondtech extruder as an upgrade, however seems that drying out filament should be good enough to get rid of clogs and ultimately all issues it this thread. Mind blowing.

About filament dryer... Before deciding, I recommend you to watch this video (6 most popular dryer tested)

Awesome video! Seems Ebox Lite is kind of best middle ground for amateur use and is far better than sunlu that I was looking at. Thanks a lot for posting it 🙂

Posted by: @cantchoose

Awesome video! Seems Ebox Lite is kind of best middle ground for amateur use and is far better than sunlu that I was looking at. Thanks a lot for posting it 🙂

Amateur or not, you wish to successfully dry any filament type in shortest period of time. In that sense, as mentioned in video, only Eibos can be called a "real" dryer (by reaching temperature up to 60C).
The rest can go only up to 45C and are thus meant for PLA in first place -of course one can dry other filaments too, but will take "ve-e-e-ry" long time.
The other usage would be, to keep (already dry) filament dry during printing -which assumes you have two dryers. For example: I already have food dryer for actually drying filament and in this case, Ebox Lite would be reasonable choice for me (if I would need a 2nd dryer).
Yes, Eibos is expensive.. but it does the job. On the other hand, you can buy food dryer three times cheaper... decisions, decisions...  🤨 

I got replacement extruder gears - there is no slack between them anymore, however clicking didn't disappear - it comes from extruder motor itself - could it be damaged after couple of clogs? 🙁

I bought back Prusament PLA and I have some very strange results.. Look at calibration cube (vase mode):

First several layers are almost perfect, then nightmare happens.. Gaps, as well as overextruded layers.

Mods that were made in meantime:

- added squash ball legs (5 of them)

- added Z support brace part ( https://www.prusaprinters.org/prints/67635-prusa-mini-z-axis-support-brace/files)

It also shows on first layer calibration print this:

I tried to look for others with issue like that but I can't (I might be poor with looking though).

All of above prints were made on PrusaSlicer 2.3.3 with default profiles for Prusament PLA , 0.2mm Quality preset and default Mini profile.

I looked through the thread again and something obvious apparently hasn't been mentioned yet. Is your grub screw (the small set screw that holds the extruder pulley in place on the motor shaft properly secured, against the flat side of the shaft? See Step 14 in https://help.prusa3d.com/en/guide/how-to-replace-an-extruder-motor-mini-mini_157410/.

If it's slipping it could cause all sorts of issues, just like what you're seeing.

I wanted to be 100% sure before I respond so I took extruder apart (again..) - it is correctly set and screwed - no slipping there. I also took opportunity to check motor, there is no slippage on shaft itself. Idler screw was set to be flush when no filament is present.

Am I missing something?

magic

I am around 70% in second cube and it is so far flawless. The only thing I can possibly think that changed was that I adjusted extruder puller slightly (to be exactly 2mm from motor as it was roughly 2.2mm).

Clicking is gone as well. 

If it returns then I will put some loctite on this screw, as  my suspision is that with fast movements and heat it could become slighthy loose (it wasn't loose when I took it apart though).

RE: I had to curse it

It lasted till half of cube. I didn't hear any clicking through whole printing, so at least this is better.

I'm running out of ideas here. Seems the problem manifest themselves at higher points in the print. That cube looks great at the base so I take that as an indication that it's not related to printer settings or underextrusion. So if it's not a partial clog, I don't know maybe it's something related to the extruder motor itself. I'm grasping at straws here... I can't recall from the previous posts, did you get on the chat with Prusa Support? If it's hardware related, they should be the best to advise you.