HF nozzle and filament profile observation
It seems that (some of) the profiles for filament are off for this new HF nozzle. I tried some Overture PETG, and just now some Prusa PETG (orange). I had to set the extrusion multiplier to 0.93 AND had to adjust the flow factor to 0.96 to get a decent print. If I understand correctly, that's the equivalent of 0.893. The default settings resulted in many blobs on prints, and knocking a 2mm high print off the platen. This did not happen on my MK4.
I have recently upgraded my MK4 to a MK4S, and have been struggling with getting decent prints again. Has anyone else noticed this problem? I'm just about ready to revert the nozzle, as all my old files won't print right. One shouldn't have to mess with old project files to get them to print again. I don't want the printer itself to be a hobby, I want the printer to support me making things. I hope filament profile updates improve, as having to mess with them defeats the purpose of having profiles.
RE: HF nozzle and filament profile observation
If you want my opinion, in all likelihood the trouble you and many others have with HF nozzles is the fact that Prusa cranked up a lot some parameters in the HF profiles, specially the max. volumetric speed in the filament advanced settings. This way, it would seem that these nozzles are capable of melting filament at a much higher rate than the non-HF nozzles, when the real gain in flow is very small.
Just use the profiles for regular nozzles and I bet you’ll be fine. No more need to readjust the extrusion multiplier and/or flow rate.
Sadly, it seems that nowadays Prusa is only interested on increasing sales, and they don’t hesitate to use every kind of bait to achieve that. One thing is optimistic marketing hype, and another thing is taking the customer for a ride.
RE: HF nozzle and filament profile observation
If you want my opinion, in all likelihood the trouble you and many others have with HF nozzles is the fact that Prusa cranked up a lot some parameters in the HF profiles, specially the max. volumetric speed in the filament advanced settings. This way, it would seem that these nozzles are capable of melting filament at a much higher rate than the non-HF nozzles, when the real gain in flow is very small.
Just use the profiles for regular nozzles and I bet you’ll be fine. No more need to readjust the extrusion multiplier and/or flow rate.
Sadly, it seems that nowadays Prusa is only interested on increasing sales, and they don’t hesitate to use every kind of bait to achieve that. One thing is optimistic marketing hype, and another thing is taking the customer for a ride.
I put my old nozzle back and used a non-IS profile (MK4) and reprinted. Used the default settings for the filament. Yes, it took longer. 43 minutes instead of 33. But guess what, it came out flawless, no blobs, no little bits sticking above the current Z level, and very little garbage deposited on the nozzle. And it printed correctly the first time, instead of taking three tries (at 33 minutes each).
This tells me that the HF+IS profiles are not very good, ie they need further development. In many ways, they are a step backwards. Just by looking about the forum, I see suggestions of fiddling with the extrusion multiplier or messing with the linear advance.
I'm disappointed at several levels. The MK4S update doesn't seem to give much, except for an improved fan shroud. But even the fan shroud is a pain in the neck, since it makes nozzle change more difficult. The ergonomics of nozzle change are just silly. Prusa has you disconnecting wiring and wire routing just to change the nozzle - that's crazy. I just loosened the thumbscrews and used the wrenches. It makes no sense to remove everything for a nozzle change. It increases the chance of damaging the wires and connectors, and takes a lot more time. It certainly doesn't value the user's time, who'd rather be doing more productive things.
RE: HF nozzle and filament profile observation
it came out flawless,
Yup. I spent a week with the HF after upgrading just to revert all my printers back to my trusted regular flow Obxidian. I don't have time or desire to deal with the fickle nature of the HF nozzle, when a few minutes longer per print makes no difference to me
The MK4S update doesn't seem to give much, except for an improved fan shroud.
Agreee. And for the kind of models I print the shroud does little if anything. Compared to the elegance of the old shroud the new one looks like a relic of the Modern Brutalism era and only gets in the way
Prusa has you disconnecting wiring and wire routing just to change the nozzle - that's crazy.
Sorta, but not anymore really. They did update their instructions
https://help.prusa3d.com/guide/how-to-replace-the-prusa-nozzle-mk4s-mk3-9s_734750
to point out that you can use the nozzle changing tool instead. Which makes a nozzle change really easy.
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: HF nozzle and filament profile observation
it came out flawless,
Yup. I spent a week with the HF after upgrading just to revert all my printers back to my trusted regular flow Obxidian. I don't have time or desire to deal with the fickle nature of the HF nozzle, when a few minutes longer per print makes no difference to me
The MK4S update doesn't seem to give much, except for an improved fan shroud.
Agreee. And for the kind of models I print the shroud does little if anything. Compared to the elegance of the old shroud the new one looks like a relic of the Modern Brutalism era and only gets in the way
Prusa has you disconnecting wiring and wire routing just to change the nozzle - that's crazy.
Sorta, but not anymore really. They did update their instructions
https://help.prusa3d.com/guide/how-to-replace-the-prusa-nozzle-mk4s-mk3-9s_734750
to point out that you can use the nozzle changing tool instead. Which makes a nozzle change really easy.
Hmm, my search found the initial article, not this one. I printed one of the heater block "wrenches". Since my printer wasn't working that well, I wasn't anxious to print something, but I left the old nozzle (low flow?) in and it printed fine. Thanks for the link to the newer article.
Had to update Octoprint so I could print a compressed file. I don't generate compressed files for my own designs.