Improving Print Quality

Did you tidy this up? I don’t see any stringing :+1:

Hey, after you have calibrated your E-Steps you are gone right to calibrate your flow with this little
“just outline in vase mode cube”
Now you have to setup your flow to get the walls to the size you want it to.

I have read you are using simplify3d and i don´t know if you have set the preferences of your process right…

Tab “Extruder”
Nozzle Diameter is 0.4mm right?
Set the extrusion multiplier to 100% for your first print (this will be adjusted, this is flow in s3d)
Set the extrusion width to manual at 0.45mm (its your choice, bigger will also work but less than 0.4mm would not work good enough)

print it slow in vase mode and be sure not to messure the wall with/including the bottom layer.

Now if you messure 0.48/0.5/0.47/0.52 or anything else, adjust the flow by a few percent and print again till your print matches your wishes.

Hope this helps!

(here is another youtube guide:

So in S3D the diameter is auto calculated to 0.48, I switched that to Manual and set to 0.48.
I did the first vase and reading were all over 0.50 so then I adjusted as per instructions so it’s much closer to 0.48 apart from 1 wall, which is a little higher.

I don’t think I can adjust again as the other 3 will probably get smaller to try and fix the outlier.

I did not tidy it. I took the photo when the printing was finished. There are few stringing actually. But I think it is good enough.

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It’s interesting, out of the box the A350 was under extruding by 10% which I corrected. Interestingly the dimensional accuracy suggests that I need to lower my extrusion rate by 10%, which does help with accuracy. However, it leaves me with gaps in the top layer again… I’m going to up the rate and see if I can find a happy balance.

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Gaps in your layers between walls and infill may be due to linear advance. Linear advance or K value is set at marlin default of 0.22, however myself and a number of other users have tested and found a k value of 0.08-0.1 to be much better.

I copy below a message I sent to another forum member on how to calibrate for K value:

"As of this moment it is a slow process to calibrate K value but possible if you have the time to do it. I used the gcode generator at this link to make a test file https://marlinfw.org/tools/lin_advance/k-factor.html

Unfortunately as the SM2.0 currently doesnt respond to M900 Kx.xx commands, you cannot use the gcode generator above to automatically test multiple K values at once. However, it is still useful as a test print. Because of this, it does not matter what k values you set using the generator.

Once you have the g-code generated, try printing it. This will be done with K0.22 as this is the SM2.0 default. You can evaluate the print performance with reference to the visual guide at this link https://marlinfw.org/docs/features/lin_advance.html.

Once you have determined whether you need to increase or decrease your K value from the initial test you will need to change the setting on your printer before running the test again. To do this, connect to the printer over usb. Once connected, type into the command line M503. This brings up the printer saved settings and you should see one of the lines says M900 K0.22.

To change your K value type into the command line M900 K0.xx (I suggest jumping right to K0.08 as this is what I found was the best setting). Type M500 to save this value. Restart your printer by power cycling and re-connect over USB and type M503 again to double check your new K value has been set. Now re-print the g-code and re-evaluate.

Rinse and repeat until you are satisfied that you are printing consistent line width!

Hope this helps."

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Circling back on this, finally got round to playing with k-factor, it made a big difference to final output.

@Dojima
I had issues similar to yours. I found that the hot end was not holding a consistent temp. I added thermal paste to the thermister and that made a huge improvement.

Happy printing,
Atom

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Is the thermal paste an adhesive? The thermister can be quite loose, once you shove it back into the print head hard to say if it is lodged in properly or not.

@Dojima
if you buy a thicker thermal paste it will help secure its location (as it hardens a little bit as it dries, more like mud than a traditional adhesive). the fact that it seats so loosely is why i recommend thermal paste. it will help with both keeping the thermister in place, as well as improve the thermal conductivity for less temperature fluctuations. i recomend Artic Silver brand (available on amazon) but really any anti-oxidant compound that states “improved conductivity” will work. i used a brand called “ox-gard” (also available on amazon) that i got as a big tube from my local hardware store. but that is much harder to apply to the tiny hole then the nice syringes.

Sorry for hijacking this thread, I printed the gcode from the k-calculator today. I manually changed all “K” to “k” within the annotations. But I can’t see any difference between the line?!

I don’t think Snapmaker can change K value on the fly during print. So the K value is what you have set in firmware. If all lines look good then you probably have a good K value set.

I though exactly that was the generator for?!?!

Snapmaker runs a version of Marlin.
Doesn’t mean it supports all the commands and functions that are possible in Marlin.

-S

I thought it would work if you put the “K” in comment in lower case?!

The accepted gcode commands can change with each new firmware release. So it might have worked at one point and does not work now? Not saying that this is what happened, just offering a possible explanation.

It was mentioned in that thread that use of the M900 command was fixed but I never actually tested this. In any case, if you follow the tutorial I linked you on another thread you can test K value manually but it is more time consuming.

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I see on your picture that it works.
Step down to run the test between 0.0 and 0.1
The most people run a k-factor of 0.08, I use 0.09 and some use 0.1.
You could better optical differences if you run the test with 20mm/s - 60mm/s (or more) - 20mm/s.

For the most print optimization it is helpful to run the extremes what you want to drive/print with normally.

Hope this helps!

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I just ran this yesterday and can report that the k factor changes on the fly just fine. I deleted out all of the k Factor comments rather than bother with changing to a lower case, figured they don’t really need to be there. Worked just fine and could see a huge difference in the resulting lines as the factor increased. In the end k = 0.06 seemed to create the best result on my unit.

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Hello,

xchrisd, regarding the video you posted. They guy explains that you’re aiming as something just over the size of your extruder width. It makes sense that under that width it won’t work. What is says goes with the theory of the picture attached below. So roughtly .03 mm or so is the total extra width we’re aiming for? My picture is just exaggerating then I guess?

Thanks
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