What is happening here?  

RE: What is happening here?

Please take a clear closeup of the ends of the idler tension screws (not the head) as well as the position of the nozzle in the nextruder. It should look like the image on this page: Nozzle Insertion Check

RE:

I opened the project file you attached earlier. Some advice, I wouldn't print this in PLA and have it up against the chamber. PETG would be a better choice. Once you move on to other filaments that require a heated chamber you may find the parts warping. 

RE: What is happening here?

Quick question while I have you.  I'm currently printing a benchy with no problems.  Why would the other print fail as soon as the first layer...but an entire benchy can print in 15 minutes with zero problems.

RE: What is happening here?

I will do this as soon as the benchy finishes

Posted by: @hyiger

Please take a clear closeup of the ends of the idler tension screws (not the head) as well as the position of the nozzle in the nextruder. It should look like the image on this page: Nozzle Insertion Check

RE: What is happening here?

Ive never really had any luck printing in PETG.  I either ended up with a bad rough print...and/or a damaged plate.  I'm sure it was user error - but just kinda gave up on that kind.  I will attempt again once I get the current problem resolved

Posted by: @hyiger

I opened the project file you attached earlier. Some advice, I wouldn't print this in PLA and have it up against the chamber. PETG would be a better choice. Once you move on to other filaments that require a heated chamber you may find the parts warping. 

RE: What is happening here?

Okay, I'll deeper dive into the extruder.  I purchased it factory assembled so not quite sure how, but I'm sure I can find a yourtube video or an article on Prusa's site.

Posted by: @hyiger

This is definitely either caused by: a clogged nozzle, debris in the extruder or perhaps the nozzle is not fully inserted into the nextruder. Either way something is blocking the filament's path through the end of the nozzle. 

First, double check the heat block assembly is correctly inserted fully into the nextruder. Next, open the idler and look for debris. Perhaps a bit of plastic is blocking the entrance to the heat break tube. It could just be you have a bad nozzle. It's always important to have a spare nozzle and heat block on hand. 

Would advise getting a spare (non-HF) nozzle and start with that. For example: Nozzles 3D Printer MK4

RE: What is happening here?

Okay, two more Cold Pulls completed..and I took apart the extruder to see inside and also see how it works.  No jams at all and no debris inside by the gear.  I did see some lint (i think), large in first zoomed in photo...that is now gone.

Trying now again with door open.  Also, yes, the vent on top is open for each one of these prints I've tried.

RE: What is happening here?

Posted by: @therandy

Quick question while I have you.  I'm currently printing a benchy with no problems.  Why would the other print fail as soon as the first layer...but an entire benchy can print in 15 minutes with zero problems.

The benchy’s first layer is tiny and in the center of the print bed. The geometry of the object being printed, in-fill and other factors control success rate. Large prints covering most of the print bed are always going to be the most problematic. 

RE: What is happening here?

Posted by: @therandy

Ive never really had any luck printing in PETG.  I either ended up with a bad rough print...and/or a damaged plate.  I'm sure it was user error - but just kinda gave up on that kind.  I will attempt again once I get the current problem resolved

Posted by: @hyiger

I opened the project file you attached earlier. Some advice, I wouldn't print this in PLA and have it up against the chamber. PETG would be a better choice. Once you move on to other filaments that require a heated chamber you may find the parts warping. 

 

I strongly recommend picking up the BIQU CryoGrip Pro Glacier build plate. You’ll have no problems with PETG (or any other filament) the exception being TPU which sticks too well to it. Also, PLA shouldn’t be used anywhere near a source of heat, or in a hot car, or outside. It warps very easily. 

RE: What is happening here?

Posted by: @therandy

Okay, two more Cold Pulls completed..and I took apart the extruder to see inside and also see how it works.  No jams at all and no debris inside by the gear.  I did see some lint (i think), large in first zoomed in photo...that is now gone.

 

Trying now again with door open.  Also, yes, the vent on top is open for each one of these prints I've tried.

Back out the idler tension screws until they are flush with the end of the idler nut. 

RE: What is happening here?

If it happens again (the gaps in the first layer) I think one or more of the channels in your high flow nozzle is blocked. Also, check that the hot end is inserted fully into the nextruder heatsink and that the thumbscrews are not loose. 

RE: What is happening here?

Okay, I have purchased multiple additional nozzles and an extra heat block assembly today for delivery tomorrow.  Thanks for all the help, really.  I’ll keep posting here the progresss.

Posted by: @hyiger

If it happens again (the gaps in the first layer) I think one or more of the channels in your high flow nozzle is blocked. Also, check that the hot end is inserted fully into the nextruder heatsink and that the thumbscrews are not loose. 

RE: What is happening here?

Posted by: @therandy

Okay, I have purchased multiple additional nozzles and an extra heat block assembly today for delivery tomorrow.  Thanks for all the help, really.  I’ll keep posting here the progresss.

If I may ask, what kind of nozzle did you pick up? 

RE: What is happening here?

Yeah, no worries! Screenshot

Posted by: @hyiger

 

Posted by: @therandy

Okay, I have purchased multiple additional nozzles and an extra heat block assembly today for delivery tomorrow.  Thanks for all the help, really.  I’ll keep posting here the progresss.

If I may ask, what kind of nozzle did you pick up? 

RE: What is happening here?

OK, that should do. I don't have any experience with the ruby nozzles but having a nozzle on-hand that can handle abrasive material is always a good choice. Just remember to turn off High-Flow and turn on Hardened when you swap it out (I tend to forget myself sometimes). 

RE: What is happening here?

also a rather silly question but worth asking... are you sure the plate is absolutely clean? Not just a swipe with alcohol but a thorough cleaning under hot water with dishwasher soap? it would be silly to discover that the two stripes where the filament is not printing are greased somehow...

RE: What is happening here?

Morning all.  Okay, sorry for the delay in updates.  On the last attempt after 2 more cold pulls AND leaving the door open, the print was successful and did not have any issues!  I tried one with the idler screws flush with the idler nut and no filament came out of the extruded…I put them back where they were from the factory and left the door open 👌

I remember reading before buying that the core one case was perfectly designed for all filaments and that the air flow design would allow the case to be closed for ALL prints 🙄 - clearly that is not the case.  Unless there is still an underlining cause and the cold pulls and door open just so happens to help mitigate the problem, but not solve it.

I’m going to change the the nozzle today and attempt another print with a fairly large first layer and I’ll leave the door closed to see what I get.

Thanks again, all. 👍

Posted by: @hyiger

One last thought. I'm 100% convinced now that its a nozzle clog. When you are printing the PLA I assume you have the top vents opened? Try doing another cold pull and leave the door open when you print (you'll need to disable the door sensor in UI setup screen). Anyway, unclogging a HF nozzle is difficult at best. 

RE: What is happening here?

Posted by: @chmax

also a rather silly question but worth asking... are you sure the plate is absolutely clean? Not just a swipe with alcohol but a thorough cleaning under hot water with dishwasher soap? it would be silly to discover that the two stripes where the filament is not printing are greased somehow...

That would manifest itself as gaps or holes for sure but not that large and even. The previous photos are showing areas where no material at all is being extruded. Anyway, seems the issue is resolved for now. Scratching my head as to why Prusa decided to include a HF nozzle with the kits and not a regular nozzle to begin with. My opinion that HF nozzles are just not beginner friendly if clogs develop. 

RE: What is happening here?

Posted by: @therandy

Morning all.  Okay, sorry for the delay in updates.  On the last attempt after 2 more cold pulls AND leaving the door open, the print was successful and did not have any issues!  I tried one with the idler screws flush with the idler nut and no filament came out of the extruded…I put them back where they were from the factory and left the door open 👌

 

I remember reading before buying that the core one case was perfectly designed for all filaments and that the air flow design would allow the case to be closed for ALL prints 🙄 - clearly that is not the case.  Unless there is still an underlining cause and the cold pulls and door open just so happens to help mitigate the problem, but not solve it.

I’m going to change the the nozzle today and attempt another print with a fairly large first layer and I’ll leave the door closed to see what I get.

Thanks again, all. 👍

Cool! To @chmax's point it also good to have IPA on hand to wipe down the sheet between prints. The Prusa sheets are notorious (in my opinion) for collecting finger prints and such, producing bad first layers. Let us know how your new nozzle is working though. It's never bad advice to purchase a spare. 

As for the door being open. I don't print a lot of PLA and the stuff I do print is specialized and can't be printed through a HF nozzle. I learned about the door trick from others getting nozzle clogs printing PLA with a HF nozzle. I'm sure there are plenty of people who have not had this issue but then all I can say is :shrug: