Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG  

RE:

Had similar issues with Mk4S, so I pretty much right away replaced the HF nozzle with an Obxidian regular flow nozzle, which I use on all my Mk4S and XL. I didn't actually see any problems in the time I used the HF but I also didn't see any spectacular speed differences so why take any risk.

RE: Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG

Man I have been struggling with PETG on the Core One.   I need to put in a non HF nozzle and see if that fixes it.  Thank you for pointing this out.  I stopped using HF on my MK4s except for a few PLA things.

RE: Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG

I’m still using a Mk4s (about to molt into a core one).  Same extruder.  But I, too, had a lot of clogging issues running PETG on the CHT nozzle.  No issues with the Prusa Obxidian 0.4 nozzle.

RE: Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG

Thanks for the feedback everyone.  While the regular brass 0.4mm nozzle seems to be working fine, I may give the Obxidian 0.4mm nozzle a try as well.

RE:

I had no issues with PETG so far. Printing with 0.4mm brass CHT nozzle and 0.6mm ObXidian HF nozzle. Printed with Prusament PETG and some other brands. Just as I live in place with around 40% humidity, I have to dry PETG often and store it sealed to achieve flawless prints (no oozing, stringing, etc.). 

RE: Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG

I more or less only print PETG in my printer and I have gone through 19kg of PETG since i upgraded to the MK4S with HF Nozzle (Also using MMU3).

Not a single clogg. I also don't dry my filament. But i only use Add:north PETG and both me and that company is in Sweden, and our air is very very dry this time of the year.

RE: Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG

This also surprises me, and makes me wonder if something else may be at work.  I didn't see any negatives when upgrading to the Mk4S CHT nozzle...I suppose other than the larger purges.  I've used the same .2 Structural preset as always, and enjoyed using the faster .28 Draft config a few times as well.  

-J

RE: Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG

The only variable for my Core One between successful and unsuccessful prints is the nozzle. Two (2) 0.4mm HF nozzles - unsuccessful prints. Switch to 0.4mm regular nozzle and successful prints. My home is very dry in the Winter - currently 22% humidity. For those having success with PETG and the 0.4mm HF nozzle, are you changing any defaults in PrusaSlicer??

RE: Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG

Out of the box, stock nozzle (which is a HF nozzle when I am not mistaken), perfect quality with PETG (tried with both an older roll of Prusa PETG and a fresh Fillamentum roll)

RISPONDI: Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG

Same issue here! I recently switched from MK4 to Core One and ran into almost identical problems using Prusament PETG with the stock 0.4mm HF nozzle — stringing, blobs, and incomplete prints. Interestingly, the same spool performs flawlessly on the MK4. I went down the same rabbit hole: replaced the nozzle, heater, and thermistor — no real improvement.

What finally worked for me was:

Switching to a regular 0.4mm brass nozzle (just like some of you suggested).

Lowering the temperature by 5–10°C from the default in PrusaSlicer.

And tweaking retraction settings slightly (extra 0.2mm).

Now I’m getting clean, reliable PETG prints again.

It does seem like the 0.4mm HF nozzle is very sensitive with PETG — maybe too much flow for standard print speeds and layer heights? Curious if anyone has optimized the HF profile specifically for PETG with better success — or if it's just better to avoid it for now.

RE: Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG

Posted by: @foxrun3d

Had similar issues with Mk4S, so I pretty much right away replaced the HF nozzle with an Obxidian regular flow nozzle, which I use on all my Mk4S and XL. I didn't actually see any problems in the time I used the HF but I also didn't see any spectacular speed differences so why take any risk.

Did you need to increase hotend temp when using the Obxidion nozzle, like others have reported - or keep everything stock?

RE: Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG

Did you need to increase hotend temp when using the Obxidion nozzle, like others have reported - or keep everything stock?

Never made any adjustments. A least in my hands, the Obxidian are drop-in replacements. In that respect they are just like the tungsten carbide nozzles I used in the pre-nextruder days. At one point I experimented with Nozzle Z and hardened steel, and yes, those required adjustments to nozzle temps—which is why they didn't last long in my workshop...

RE:

No issue with Hatchbox Petg here, in fact I'm printing a part as we speak. I just tweaked the generic Petg profile a little for temps and thats it. I might try to push the speed up a bit at some point but quite happy with how it's printing for now.

Edit: using stock High-flow Prusa Nozzle brass CHT - 0.4 mm nozzle. Filament dried to around 20% RH, printing directly from drier.

RE: Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG

I had horrible issues with PETG after upgrading MK4 to MK4S with the high flow nozzle.  Read somewhere that the nozzle might be the issue, so I switched back to the one I took out of my MK4 during the upgrade process.  Still saw some issues occasionally, but I was kind of new to PETG at the time so I managed to figure out that the temps I was using were just too high for the brand of material I was using (Overture).  I want to say I have that profile locked to 230° on the extruder and 80° on the heat bed.  Works great now every time, but I do use glue stick on the bed as well.

RE: Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG

Posted by: @foxrun3d

Did you need to increase hotend temp when using the Obxidion nozzle, like others have reported - or keep everything stock?

Never made any adjustments. A least in my hands, the Obxidian are drop-in replacements. In that respect they are just like the tungsten carbide nozzles I used in the pre-nextruder days. At one point I experimented with Nozzle Z and hardened steel, and yes, those required adjustments to nozzle temps—which is why they didn't last long in my workshop...

Exactly what I'm after. I have the Obxidion High Flow version, which I am going to list up on eBay and purchase the non-HF version instead......

RE:

I had to increase my temperature 5 degrees with the obxidian 0.4 non HF, switched to a Diamondback nozzle and everything just printing perfectly so far. Only used PLA, various brands of petg and prasa PCblend.

Really liking those nozzles.

RE: Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG

Posted by: @chocki

I had to increase my temperature 5 degrees with the obxidian 0.4 non HF, switched to a Diamondback nozzle and everything just printing perfectly so far. Only used PLA, various brands of petg and prasa PCblend.

Really liking those nozzles.

So you had better luck with default temp values with the Diamondback?

How are you find the Diamondback different to the ObXidion, and which do you prefer?

RE: Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG

I've been using the Prusa HF nozzle with PETG without issue.  I also print Hatchbox filament and use the Prusament profile. 

Almost no stringing.  This is with black, and filament is dried and printed directly from a drybox.

Colored PETG does not print as nice and will have some nozzle buildup and light stringing.  Something about the pigment changes it's properties.  White is the worst. 

RE: Love / Hate Relationship with Core One 0.4mm HF Nozzle Printing PETG

I found with the obxidian and petg I got a few zits as well as having to run higher temps. The Diamondback seems to print cleaner and there isn't the oozing some people said may occur.