print speed slow

[Zippojack]

after uppdating to main board LA IS the printer printet mush slower? any idea what may be the issue?

[rommulaner]

Maybe this is caused by a high value of Linear Advance.

[Zippojack]

hmm. i set the value to 0.75? after i tested, it felt like the correct setting.. i changed the k value in the g code on octoprint. after i did that i noticed that i could change it on the screen as well and i changed it from 0.2 - 0.75 during a print. ?

[rommulaner]

0.75 is quite high. I print at 150mm/s and have LA at around 0.06. the higher the value the slower the print.

[Zippojack]

0.06?? when i tested using K-factor Calibration Pattern form https://marlinfw.org i got 0,75 that was good for me, is 0,06 gonna do anything at all ?

[rommulaner]

There is also my Orca profile in the release to download. Try it.

[convicte]

There is also my Orca profile in the release to download. Try it.

Hi there @rommulaner, thank you so very much for your work. Installed your firmware pack yesterday and it's giving me amazingly nice looking prints.

This said, I was trying to see your Orca setup and when I try to import your setup in a fresh out of the box Orca 2.0 (https://github.com/SoftFever/OrcaSlicer/releases/tag/v2.0.0) I am getting:

There are 0 configs imported. (Only non-system and compatible configs)
Hint: Make sure you have added the corresponding printer before importing the configs.

I've both tried with adding a generic Marlin printer as a base as well as Anycubic Vyper, and both give the same result.

[rommulaner]

I used Orca 1.9.1 since now. I just updated and exported the profile again. I replaced it in the release 6.2.2. It should work...

[convicte]

0.06?? when i tested using K-factor Calibration Pattern form https://marlinfw.org i got 0,75 that was good for me, is 0,06 gonna do anything at all ?

You and @rommulaner seem to be conflating completely different parameters and comparing them to each other. I may be mistaken, but you are referring to the K value from M900 command, which from my test a moment ago I am seeing to be giving best results around 0.65-0.80, while @rommulaner is probably talking about the 'pressure advance' in the Orca slicer:

TeachingTech on Youtube says the two shouldn't be used at the same time and when set up in firmware, all slicer level settings should be switched off: https://youtu.be/n3yK0lJ8TWM?si=gJVCNZIackd2QXtX&t=594 What would be your thoughts @rommulaner ? Citing Marlin docs:

Thanks!!

[rommulaner]

In OrcaSlicer it writes an M900 command in the gcode if a pressure advance value is defined. So LA and PA is the same. Maybe the E acceleration and E jerk limits the print speed at high LA values. I'll test that.

[rommulaner]

I just tested some changes and even with higher E acceleration I don't get good prints with higher LA values. 0.15 works also good, Instay at 0.06. I also updated again the OrcaProfile as the travel acceleration was too high with 5000. 3000 works better.

[convicte]

I just tested some changes and even with higher E acceleration I don't get good prints with higher LA values. 0.15 works also good, Instay at 0.06. I also updated again the OrcaProfile as the travel acceleration was too high with 5000. 3000 works better.

I am not sure what is, but something must be different in the numbers we are comparing, since we use the same hardware but both @Zippojack and I need >0.50 LA for the best results. You are saying it's an order of magnitude lower for you. Having looked at a bunch of Youtube clips of people using the Marlin calibration procedure (https://marlinfw.org/tools/lin_advance/k-factor.html) majority of them would be also in the 0.3-0.8 and not 0.0x... Not sure where the disconnect is.

[rommulaner]

If I do the calibration print I also get a higher value of about 0.4 but in the print with this high speeds it doesn't work. Print a 50x50 square and adjust the LA during the infill then you see.

[convicte]

Ok, so it's a dissonance between an idealistic calibration pattern scenario and real life experience - got it! Makes sense!

Would you mind explaining a bit more what you mean by the 'Print a 50x50 ...' How would I achieve a variable LA during infill?

Cheers, Bartosz

[rommulaner]

Just slice a cube around 50x50, so the head can speed up to the set speed during the print moves. You can adjust the LA value during the print on the screen of the printer as you want. I just print two layers of it and cancel the print. The first layer as slow print and the second layer as normal speed print, normally the setup is like that with only first layer on slow speed. Start with a low LA value und raise it until you are happy. Make sure that you set the LA value globally in the slicer and not different values for each wall type otherwise the set value on the screen will be always overwritten. Or disable it, so then it uses the standard setting from the firmware.

[convicte]

I've done a lot of different tests and at the speeds from your profile I end up with needing roughly PA 0.21 - 0.25.

Here is the methodology (please let me know if I am doing something wrong): 1) Nozzle 0.4 and 0.6 - with your profile for the 0.4 and a modified 0.6 with 0.4 layer height. 2) Below the PA tower test from Orca - set to: 3) The outcome as follows: 4) Having measured across all different test (corner) types - I am looking at 10-13 mm height being the best 5) The calculation then will be PA=height x step of tower so my_PA=12 x 0.02 -> 0.24

Would love any constructive feedback!

Other take home messages: 1) I may be reaching max flow capacity of my hot end at the current temp 210C 2) Need to update my cooling as I've been seeing too much sag in places

[rommulaner]

Yesterday I changed my value to 0.15 and it's a bit better on the corners to get them sharper.

[convicte]

I've set mine to 0.22 for the moment, and will dial it back, if need be.

What I struggle to get right is the temp and overhangs, but I think it's related to the room temp in my server room getting toasty 25-30C these days. The default cooling being non-existant in the Vyper, just not keeping up, at your speed settings.

Did you upgrade your cooling to some ducted setup: https://www.thingiverse.com/thing:4974423/files

This is after feed rate calibration in Orca already.

Maybe I've got this wrong, and you would recommend tweaking something else a bit?

[rommulaner]

If the part isn't as small as the temp tower I don't have big problems with overhangs. It's still the stock cooling. Printing at your high environment is of course not good for the overhangs. There you need to print slower. Would be easy to setup if you just lower the volumetric flow to lower the speed for better results.

[convicte]

For this latest print I brought it down to 12mm3/min as compared to the standard 18mm3/min you had.

Trying to get the ducted cooling printed. We'll see!

Any other recommendations?

[rommulaner]

Slow down as much you need or point an external fan to the print. Perhaps a different filament type like ASA could work quite well.

[convicte]

I'll hopefully succeed with this latest print for the ducting and upgrade to it, as I already have all the parts anyway.

Thank you for all the suggestions!

[convicte]

I am so confused!

The print above failed with skipped filament rows and gaping holes due to under-extrusion.

EDIT:

I then went to do a max flow rate run to see how low does it fail, if it failed in a real print at 12mm3/s. The test model was set to 5-20mm3/s at 0.2 increment and it didn't fail at all at 12. nor even at 20... Hell, it's probably able to do almost 20-25mm3/s, with just minimal deterioration (going from matte to shiny)

Why all test model succeed while real life prints have such extrusion issues in the exact same environment and filament. Doesn't make much sense unless it's 100% pure temp creep and layer bubbling issue.

[rommulaner]

To me it looks like a wet filament. On high flow rates you don't have a problem with that, but when it's slower and needs to corner you get these bubbles. I never had a print like this on my vyper.

[rommulaner]

Could you solve the problem?