1mm Nozzle Seam Issues
I decided to try a 1mm nozzle on my VC4 and I'm really happy with how I've been able to get it dialed in, except for the seams. On the outer walls, I'm getting scaring (under extrusion) and on the inner walls I'm getting blobs. This is with Sunlu's High Speed PETG, using OrcaSlicer.
I've played around with retraction settings a bunch, and I've been able to improve the issue by bringing retraction down to 0.05mm (tried a range from .8mm to .05mm) and keeping extra length on restart at 0mm (tried a range from .8mm to 0mm), but I can't seem to solve the outer wall holes without making the inner seams significantly worse.
I have calibrated my flow, temp, and max flow rate using OrcaSlicer's calibrations, and I've disabled pressure advance for the time being.
Anyone else who's running larger nozzles - any tips or suggestions?
14 Replies
Small update, as I was expecting, dropping to 0mm retraction from .05 made no difference
It sounds exactly like a pressure advance issue.
Without a picture of the prints we are just guessing, but; yeh, sounds like you need to enable pressure advance and tune it.
I've given up for the time being and moved down to a 0.8 nozzle since there are already well tuned profiles. Running the pressure advance tuning in klipper's docs consistently had the best results at the start of the print, which is 0 if I'm understanding correctly. What did improve my holes in the print was messing around more with the retraction settings. Going back to 0.4mm of retraction with 0.4mm of extra length on restart seemed to help, and then reducing the wipe distance from 1mm (default) to 0.4mm made a huge difference. Still not the seam I'm used to seeing on smaller nozzle sizes, but closer to normal
Yeh pressure advance and retraction are linked. It's what made me suspect pressure advance is your issue.
Is there a reason you're using Klipper's PA tuning rather than Orca's?
I was simply following the commissioning guide from ratrig, which points to the klipper docs for pressure advance.
I’ve had many printers over the years, but this is my first klipper machine and I’m still getting familiar with the details. Do you recommend the orca tuning instead?
Yes, I don't like the Klipper model
Personally I really like the Orca line test, but many prefer the pattern test - both are much better than the Klipper model
Having the same problems even with the 0.8 nozzle and stock orcaslicer profiles, so currently trying the pattern test.
Here’s a picture of what I’m seeing. The seam is consistently missing material. Hard to get a good shot of a black object but hopefully this helps
If it's just your seam that you're having issues with and you're not having any problems in corners etc, then just try playing with your seam gap in the filament settings.
I think default is 10%, I often drop that down to 0-3% and occasionally some materials like a - value
Not sure how I've never seen that setting... giving it a shot now
And thanks for the tip about orca's pa calibrations. Definitely got more useful info from the pattern test than with klipper's
It was still set to the default 10%. Dropped it down to 1% and saw no change (somehow??) in the seam behavior. Currently trying -3% just for giggles, but don't have high hopes
Yeh in that case it's almost definitely a nozzle pressure issue.
But I'm almost certain you could fudge it with really high - numbers if you needed to. Big nozzles need funny settings sometimes, and at the end of the day if it works then it's not wrong!
But hopefully between the Orca PA calibrations and the seam gap settings you can get it sorted 🙂
I guess I'm not really understanding what the pressure advance number means then. Is there such a thing as negative PA value?
At 0 pressure advance on the pattern method, the corners have slight bulges. At 0.03, they look really good. At any higher, they start to get rounded off and under extruded.
At the same time, at any of these values, I see no change in my seam behavior
Or maybe the question I should be asking is where should I enable pressure advance? Following the commissioning guide, it seems I should be putting it into the printer.cfg file. But I also see that there's a pressure advance field in the filament settings in orca.
For anyone else looking at this in the future... I still haven't dialed the seam in, but I have managed to reach the opposite problem point. My seams are now over extruded by a fair bit, but it's close enough for me to get the current project off my workbench.
Biggest influencer in changing the seam behavior has by far been in the retraction settings under printer settings in orca. Retraction length seems fine in the stock profile, but adding extra length on restart has been huge. On the 1mm nozzle, 0.4mm of extra length helped immensely. It seems to be too much on my 0.8mm nozzle.
Decreasing wipe distance has also been a pretty big help. Default was 1mm, I brought it down to 0.4mm with good results.
Pressure advance (in my particular case) had a negligible impact on the seam issue, but did help other aspects of my prints once I dialed it in better. Still unsure of where that value needs to be, but I have it enabled in both printer.cfg and orca's filament settings.
Seam gap setting (Quality > Seam > Seam gap in orca) is extremely useful in dialing in the finer detail of seam, but could not make up for the ~1.6mm gaps I was having at seams.
I still have a lot to tweak and learn to get to a good point, but I am finally at something I can use
Yeh so there's two ways of handling pressure advance. You can enable it in the slicer, or you can use Klippers native control. If you enable it in the slicer, then you DONT want to be using the firmware. If you're using firmware then you don't want to be enabling it in the slicer.
There's different schools of thought on this so you'll find conflicting information on it. For me, I prefer to do all of this stuff in the slicer.