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First layer calibration  

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YigalB
(@yigalb)
Eminent Member
First layer calibration

The first layer calibration is a time consuming process, unless I miss something, because every iteration the temp goes down to 170 for bed leveling, and then back to 210, and only at the end it displays the square of small lines. It is hard to do any change of the nozzle height dynamically, and see the difference. Perhaps if the machine could do several heights at same time, so the result would be something like 20 different squares of small lines, each with another height. It would make the selection process easier. Makes sense?  

Posted : 20/07/2021 1:18 pm
hli
 hli
(@hli)
Trusted Member
Life adjust Z my way...

https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/ gives you a larger area to work with, so you can try multiple Z heights in one print.

Posted : 20/07/2021 1:31 pm
YigalB liked
DRKMSTR
(@drkmstr)
Trusted Member
Live Adjust Z

The best solution is to print single layer squares (with a long single line tab at a corner for easier removal) and adjusting up and down between each  test. 

Ideally you should have almost no smudged lines on the top of the part / bumps that protrude above the rest of the printed surface (nozzle too close to build plate) and after you peel the part off you should be able to fold the square diagonally to the printed lines and it should not break or bend along those lines. 

I'll do a quick print and post pictures this evening.

Also some filaments don't like perfect first layers, some want to be a bit higher or a bit more smooshed. You can also increase your first layer tolerance by increasing the "first layer height" from 0.2mm to 0.25mm.

Best of luck!

Posted : 20/07/2021 1:54 pm
YigalB liked
DRKMSTR
(@drkmstr)
Trusted Member
...because I cannot edit old posts...

You can also edit the startup GCODE in these prints to remove the 170C cooldown requirement. This seems unnecessary when using the newer Z probe. My guess is that it was either to reduce temperature related effects on the probe and/or reduce filament oozing out the extruder during the z-probing process. 

Posted : 20/07/2021 2:07 pm
YigalB liked
BogdanH
(@bogdanh)
Honorable Member
We just need to deal with that

Yes, first layer calibration can be quite complicated, especially for new 3D printer owner. Without previous experiences, it's hard to recognize when first layer is "just right". And when that happens (with luck involved), then new user usually try to avoid any changes which could lead to calibration again. But as mentioned in previous post, there will always be the need for new calibration. So one just need to bite the challenge and learn that process by practicing -and important: to understand how printing works (because one just shouldn't rely on luck).

The idea of auto printing, say, ten squares with different Z-offsets (where user would at the end choose the best square) is very interesting. The problem is, for that to be possible, printer would need a sensor which would measure distance to print bed with very high accuracy. But we know that SuperPINDA doesn't measure distance -it only gives reference distance point.

As far I know, on all home 3D printers filrt layer calibration needs to be done manually, where process differs only slightly. The only printer that I'm still unclear in this regard is Anycubic Viper... I watched few reviews and it appears to me, that after auto bed leveling nothing more is needed to be done -the reviewer just starts with printing. Very interesting.

[Mini+] [MK3S+BEAR]

Posted : 20/07/2021 2:41 pm
YigalB
(@yigalb)
Eminent Member
Topic starter answered:
RE: First layer calibration

 

Posted by: @bogdanh

Yes, first layer calibration can be quite complicated, especially for new 3D printer owner. Without previous experiences, it's hard to recognize when first layer is "just right". And when that happens (with luck involved), then new user usually try to avoid any changes which could lead to calibration again. But as mentioned in previous post, there will always be the need for new calibration. So one just need to bite the challenge and learn that process by practicing -and important: to understand how printing works (because one just shouldn't rely on luck).

The idea of auto printing, say, ten squares with different Z-offsets (where user would at the end choose the best square) is very interesting. The problem is, for that to be possible, printer would need a sensor which would measure distance to print bed with very high accuracy. But we know that SuperPINDA doesn't measure distance -it only gives reference distance point.

As far I know, on all home 3D printers filrt layer calibration needs to be done manually, where process differs only slightly. The only printer that I'm still unclear in this regard is Anycubic Viper... I watched few reviews and it appears to me, that after auto bed leveling nothing more is needed to be done -the reviewer just starts with printing. Very interesting.

Thanks for the reply. My Prusa Mini gave some suffer time until I got into a working mode, and for weeks it was just perfect. I tried to breath quietly near by, but suddenly printing started to disconnect from the bed after while. About the sensor - I don't think we need a special one, as the user can insert the boundaries. Although I wonder why not have a good sensor, that knows exactly the distance. The frustration thing I noticed: when the calibration looks well (the lines in the box are well separated), the more the printing gets disconnected from bed. Dame prints reached the end with a "worst calibration square". Made me think if there is something else I am missing. 

BTW - I use PLA+ from eSun with defaults parameters. The only change I do is adding supports when needed.

This post was modified 3 years ago by YigalB
Posted : 20/07/2021 3:55 pm
YigalB
(@yigalb)
Eminent Member
Topic starter answered:
I will try this cool solution

 

Posted by: @hli

https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/ gives you a larger area to work with, so you can try multiple Z heights in one print.

Thanks ! I will check it. Sounds like a cool solution.

Posted : 20/07/2021 3:59 pm
BogdanH
(@bogdanh)
Honorable Member
first layer print

@YigalB
I don't understand what you mean by "the lines in the box are well separated"... they shouldn't be separated. If they are separated, that means nozzle is too high and print won't stick to bed. With good first layer, box must be a solid (thin) surface where lines stick to each other (as in this example).
Just clarifying misunderstandings 🙂 

[Mini+] [MK3S+BEAR]

Posted : 20/07/2021 6:52 pm
YigalB liked
YigalB
(@yigalb)
Eminent Member
Topic starter answered:
First layer print

@BogdanH Aha, good point. I was sure that the separation means better resolution. 

Posted : 20/07/2021 7:03 pm
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