For FDM printing, how fine a thread is practical?

[7milesup]

There are so many variables and possibilities to make this work better.
A .20mm might help quite a bit for example. Slowing the print speed down, along with cooling, can make a difference.

As you mentioned, filament can make a big difference, but trying to sort that all out is maddening. Once you change filaments, one should do new calibration tests, including pressure advance. This can even change with the same filament but in a different color. I am still on the quest to find a good filament and stick with it.

It does look like you have a win for the most part. Congrats.

 

[WobblyHand]

There are so many variables and possibilities to make this work better.
A .20mm might help quite a bit for example. Slowing the print speed down, along with cooling, can make a difference.

As you mentioned, filament can make a big difference, but trying to sort that all out is maddening. Once you change filaments, one should do new calibration tests, including pressure advance. This can even change with the same filament but in a different color. I am still on the quest to find a good filament and stick with it.

It does look like you have a win for the most part. Congrats.

Not sure where to look for pressure advance. I have had a couple recommendations to look at this. This is in the slicer? Typically in what section? I'm just a novice and still using PrusaSlicer, so that's my limited view of the world. I have found links to test files, but not where I would control this parameter. Or is it in the printer itself? Sorry for the simplistic question - it's outside of my experience.

Edit: in the PrusaSlicer this is hidden in some gcode that is dependent on the filament selection. But this is not a filament that Prusa has profiled. So it seems I need to run the tests to determine what the "best" K factor is. I read a little about it. It's slightly over my head, but eventually I may figure it out.

 

[7milesup]

Not sure where to look for pressure advance. I have had a couple recommendations to look at this. This is in the slicer? Typically in what section? I'm just a novice and still using PrusaSlicer, so that's my limited view of the world. I have found links to test files, but not where I would control this parameter. Or is it in the printer itself? Sorry for the simplistic question - it's outside of my experience.

Edit: in the PrusaSlicer this is hidden in some gcode that is dependent on the filament selection. But this is not a filament that Prusa has profiled. So it seems I need to run the tests to determine what the "best" K factor is. I read a little about it. It's slightly over my head, but eventually I may figure it out.

Sorry for the late reply.
I am not 100% familiar with PrusaSlicer, but you would need to be in the "Advanced" mode. You are correct that tests must be done, and each filament would be saved as its own profile. This parameter should be found in the filament section. For example, if I used Zyltech Dark Blue ABS I would do a test and save that as a profile. Each filament would have a profile vs a generic. This is somewhat new to me, too, because I am trying to dial my Voron 2.4 in, and it seems like everything I do is always more complicated than it should be.

I should point out that I am using OrcaSlicer, which is a morph of PrusaSlicer and Bambu Labs, and therefore, I am not 100% sure where it is in PrusaSlicer, but I would think that it would be the same.

 

[WobblyHand]

I'm always skeptical of adopting someone's calibration gcode. Did it once and scratched my build plate because, unknownst to me they didn't include any bed calibration/z offset in their code. I know better now, but am not yet gcode aware enough to avoid issues.

I will look into this as the print goes fine for quite a while but then the slicing changes and micro blobs come out and end up on the z layer or the nozzle. If a big enough blob, there's some kind of crash with the head. I've seen stuff fall off the nozzle and harden on a layer and then a crash. It's to the point that I have to babysit the printer on some prints and examine the nozzle every 3mm or so and clean it it necessary. Not much fun.

The picture I posted earlier of my first attempt was when I walked away for dinner. Came back to a mess of spaghetti and a knocked over piece. So there's some motivation to look into this further.

 

[MikeWi]

I'm always skeptical of adopting someone's calibration gcode.

You should be. Someone else's settings will never work as well for you. As someone else said, too many variables.

Pressure advance depends on what software you are using on the printer, not the slicer. Klipper uses Pressure Advance, Marlin calls it Linear Advance. Not sure what else is out there. There's a calibration process to go thru, and this gives you settings to use in that software. Then you place code in your slicers (they all have a place to do this) that turns on whatever system your printer is using for that, and sets the variables that you found in your testing. This way you can have a specific setup for ea. type of filament.

The blobs normally happen when the print head pauses, and filament continues to ooze out. Temperature affects this, but you can also use retract settings in your slicer to try to suck back the filament when it pauses. It could take both to stop it. Another possibility is travel speed. The longer it takes to move to the next position without extruding, the more time it has to ooze out of the nozzle before printing again.

PETG is more prone to this than others, but you can fix it.

 

[WobblyHand]

You should be. Someone else's settings will never work as well for you. As someone else said, too many variables.

Pressure advance depends on what software you are using on the printer, not the slicer. Klipper uses Pressure Advance, Marlin calls it Linear Advance. Not sure what else is out there. There's a calibration process to go thru, and this gives you settings to use in that software. Then you place code in your slicers (they all have a place to do this) that turns on whatever system your printer is using for that, and sets the variables that you found in your testing. This way you can have a specific setup for ea. type of filament.

The blobs normally happen when the print head pauses, and filament continues to ooze out. Temperature affects this, but you can also use retract settings in your slicer to try to suck back the filament when it pauses. It could take both to stop it. Another possibility is travel speed. The longer it takes to move to the next position without extruding, the more time it has to ooze out of the nozzle before printing again.

PETG is more prone to this than others, but you can fix it.

Thanks. In this case, the printer was traveling pretty fast, so there's little time to ooze. Think it's some sort of retraction thing or linear advance. In the past, I tried modifying retraction, but it made little difference. However, that was before I upgraded my printer. The dynamics of the head are quite different now. Extruder is different as well.

 

[7milesup]

I'm always skeptical of adopting someone's calibration gcode.

I think that there is a misunderstanding here. You would not be using someone's Gcode. When you adjust your printer's settings, such as filament temps or pressure advance, you save that as a profile. That profile is saved locally on your hard drive, so the next time you open your slicer that particular filament that you already tested is ready to be "loaded" into your slicer.
I would never use someone else's g-code for a print. That is a disaster waiting to happen.

 

[MikeWi]

When I was helping out with the Klipper forum, people would frequently ask for someone's configuration, thinking that they could just do that rather than go thru the tuning. I guess I'm just used to people referring to that now!
Gcode can be used, if it doesn't have any printer settings in it, (you add those in). However, you need to be highly skeptical of the code you use from someone else. If you don't know them, just don't do it.

 

[WobblyHand]

I think that there is a misunderstanding here. You would not be using someone's Gcode. When you adjust your printer's settings, such as filament temps or pressure advance, you save that as a profile. That profile is saved locally on your hard drive, so the next time you open your slicer that particular filament that you already tested is ready to be "loaded" into your slicer.
I would never use someone else's g-code for a print. That is a disaster waiting to happen.

What I meant by this was someone had created a calibration printing test for some parameter tuning. But this file was incomplete - and I as a beginner didn't know that.

As for the pressure advance or linear advance, I found where it is done in a special section that the slicer puts in the beginning of the gcode of a print. I was using Overture PETG, but using the profile for Prusament PETG. The command that the MK4 uses is

M572 Sxxxx to set linear advance.

Prusament PETG has a value of 0.055. Apparently Overture PETG needs a different value. These little blurbs don't happen often in a simple print, but the fine threaded part (that initially failed) had some interesting slicing and rapid accelerations in it. Apparently, for 0.1mm SPEED & DETAIL profile, 0.055 is not a good value for Overture PETG. So sometime I will mess with it, hopefully with some special test print that I can understand.

As a total guess, I'd think too much was applied for this filament, so I'd reduce it.

As an aside, the SainSoft TPU I was printing today has a pressure advance of 0.