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dennis.p8
(@dennis-p8)
Eminent Member
First layer problems

Hey all!

Two weeks ago I bought my first prusa MK3 and built it myself almost succesfully. I am dealing with a problem regarding the first layer not printing properly. First I ran the g-codes G80 and G81 to check if there is a problem with my P.I.N.D.A. probe. the variation kept below 0.2mm so it is not the sensor.Attached I have the output of the G80 code. Can any of you tell me what I can do with this data? Does it tell me the bed is not perpendicular enough? A second thing that worried me, my y distance to min. seems not good to me. On the internet I have read the values should be close to each other. Anyways, my opinion the bed is not good, because I have checked everything and I don't know what to do now.

Please discuss your suggestions!

Thanks in advance.

Posted : 02/10/2018 2:02 pm
stahlfabrik
(@stahlfabrik)
Honorable Member
Re: First layer problems

Hi!

0.2mm is one layer height! If your variance in between two measurements is so big, your PINDA is NOT performing well. PINDA should be quite repeatable (at a constant temperature) so more like 0.02mm.

What you can do with the data is to visualize it. I would suggest to use octoprint and a nice plugin for that https://github.com/PrusaOwners/OctoPrint-PrusaMeshMap

You could then try to improve on our overall bed variance. There are several methods for that, starting with a very thorough build of your printers Y and Z axis. Other methods introduce springs under the bed spacers, or get rid of the spacers and adjust the height by screws.

https://github.com/PrusaOwners/prusaowners/wiki/Bed_Leveling_with_Wave_Springs
https://github.com/PrusaOwners/prusaowners/wiki/Bed_Leveling_without_Wave_Springs

But you did not state WHAT the problem you are having is - so I can only give general advise here.

So what problems DO YOU have exactly?:-)

Posted : 02/10/2018 2:31 pm
thrawn86
(@thrawn86)
Honorable Member
Re: First layer problems


0.2mm is one layer height! If your variance in between two measurements is so big, your PINDA is NOT performing well. PINDA should be quite repeatable (at a constant temperature) so more like 0.02mm.

prusa has a support page that I can't find at the moment and suggests that you're shooting for less than .2 between physical (not interpolated) points. I agree that "not printing properly" could mean anything, but I still wonder why some probes are much more inconsistent than others.

Posted : 03/10/2018 5:41 am
dennis.p8
(@dennis-p8)
Eminent Member
Topic starter answered:
Re: First layer problems


Hi!

0.2mm is one layer height! If your variance in between two measurements is so big, your PINDA is NOT performing well. PINDA should be quite repeatable (at a constant temperature) so more like 0.02mm.

What you can do with the data is to visualize it. I would suggest to use octoprint and a nice plugin for that https://github.com/PrusaOwners/OctoPrint-PrusaMeshMap

You could then try to improve on our overall bed variance. There are several methods for that, starting with a very thorough build of your printers Y and Z axis. Other methods introduce springs under the bed spacers, or get rid of the spacers and adjust the height by screws.

https://github.com/PrusaOwners/prusaowners/wiki/Bed_Leveling_with_Wave_Springs
https://github.com/PrusaOwners/prusaowners/wiki/Bed_Leveling_without_Wave_Springs

But you did not state WHAT the problem you are having is - so I can only give general advise here.

So what problems DO YOU have exactly?:-)

Thansk for the octoprint advice, I ordered one today! To answer your pinda probe variation question, look at this link:
https://help.prusa3d.com/l/en/article/3tSXh6nWJd-pinda-probe-testing

I am gonna wait till my raspberry Pi is delivered and I will run the plugins.

Posted : 05/10/2018 7:19 pm
andy.b15
(@andy-b15)
Active Member
Re: First layer problems

Following. My bed shows a similar slope in octoprint but I can't determine the cause.

Posted : 05/10/2018 8:40 pm
dennis.p8
(@dennis-p8)
Eminent Member
Topic starter answered:
Re: First layer problems


Following. My bed shows a similar slope in octoprint but I can't determine the cause.

I have fixed the y min issue, what is your problem exactly?

Posted : 05/10/2018 8:53 pm
andy.b15
(@andy-b15)
Active Member
Re: First layer problems


I have fixed the y min issue, what is your problem exactly?

I have two things going on. One is a slope from left to right when probing, and the other is a fluctuation in Z height across the bed. Prusa sent me a new heat bed and Y carriage but it made no difference.

Posted : 05/10/2018 9:07 pm
dennis.p8
(@dennis-p8)
Eminent Member
Topic starter answered:
Re: First layer problems



I have fixed the y min issue, what is your problem exactly?

I have two things going on. One is a slope from left to right when probing, and the other is a fluctuation in Z height across the bed. Prusa sent me a new heat bed and Y carriage but it made no difference.

IMG_0059.jpg
Screen Shot 2018-10-05 at 3.05.40 PM.png

I recommend two things for you:

1. Try to adjust the left side or right side with 'bed level correct' option under the tab calibration. As I look to your pictures you can clearly say the right side is much lower than the left side. the good thing is, the variation goes into layers and not like the middle is lower than the left side. So adjusting the mesh bed leveling should do.
2. Try these two links someone posted in this thread:

https://github.com/PrusaOwners/prusaowners/wiki/Bed_Leveling_without_Wave_Springs
https://github.com/PrusaOwners/prusaowners/wiki/Bed_Leveling_with_Wave_Springs

I have read both of them and they really give good information! Unfortunately I have to wait till I have my raspberry Pi. If you have tried any of these options, can you tell me what was the output of it? I recommend you try option 1 first. If you need any help with getting STL files, I got some for you if you want. I understand you don't want to print all the blocks all the time. I got some STL files which only prints the 3 blocks on the left or right.

Posted : 05/10/2018 9:23 pm
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