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XYZ first calibration point not found. Frustrating.  

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Digitalfire
(@digitalfire)
Active Member
XYZ first calibration point not found. Frustrating.

I am pretty sure I have this put together correctly. I have assembled another before.
It puzzles me that the head is scanning (very close to, but no touching, the bed), in a circular pattern and then back and forth in a square, but the circle printed on the bed (which I am assuming is what it is looking for) is a little to the right and back of where it is scanning (included image shows, I do have paper in place). Thanks.

Posted : 05/08/2019 6:49 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: XYZ first calibration point not found. Frustrating.

when you say head! do you mean extruder nozzle, or Pinda probe?

It is the Pinda Probe that does the sensing, and as the Pinda probe is offset to the right of the extruder assembly, I can't see how it's searching the area you show... 

the picture above shows the nozzle at the left most extremity of the heat bed, and the Pinda, with the white end, is to the right of the ned retention screw

If your yellow elipse, shows the nozzle path, then the Pinda path is probably around the sense point. 
this activity does take sometime, could you be aborting it before it has finished?

Regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 05/08/2019 11:56 pm
Digitalfire
(@digitalfire)
Active Member
Topic starter answered:
RE: XYZ first calibration point not found. Frustrating.

Thanks. That is reassuring because I thought there could be issues with circuitry in the bed that was sensing nearness of the head.

The head looks to be about the thickness of a credit card away while the Pinda it is searching for the point on the bed. Is the Pinda sensor enabling the printing assembly to bring the head that close or is it guessing? Is it scanning looking for a magnet embedded in the bed? If it can get that close to the bed how could it not be able to sense the magnet?

Posted : 06/08/2019 9:47 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
RE: XYZ first calibration point not found. Frustrating.

the pinda is sensing a copper pad in the heatbed, trying to ascertain where the pad is, in 'space' it should then move on to locate three more pads, in order to identify their relationship to each other,  these tests enable the printer to measure the accuracy of the build, and if found wanting, the printer will try to compensate for the build skew in which ever planes they are recorded...
the pinda is not fantastically accurate, so it does a lot of passes over each sense point, changing X, Y and Z relationship in different combinations, to improve accuracy.  later in calibration, you put the steel build plate on the heatbed, complete Z calibration and then complete first layer calibration (adjusting Live Z... ), during this adjustment, the pinda senses the build plate,in various spots (either 3x3 matrix with 9 sense points, or 7x7 matrix with 49 points) to try and measure the surface undulations in the heatbed. so that the printer can try and compensate for lumps and hollows in the bed surface,with the result that the printer arbitrarily sets the best height above the bed that it can measure(But the nozzle should be safely, too high..., then during Live Z adjustment, you move the nozzle progressively closer to the heatbed, whilst observing the resultant filament deposition, on the heatbed. increasing live Z  from 0.00mm towards a more negative number, until your filament trace is suitably squashed into the heatbed. 

this page might help https://cults3d.com/en/blog/articles/6-main-factors-for-perfect-first-layer-3d-printing

tramming is the technical term for the Pinda asessing the lumps and bumps and angular displacement of the heat bed/build plate, relative to the extruder nozzle path...

I hope this helps, regards Joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 06/08/2019 11:59 pm
Digitalfire
(@digitalfire)
Active Member
Topic starter answered:
RE: XYZ first calibration point not found. Frustrating.

I got it solved. Thanks for the help. A question on another thread about whether the x-axis was able to move all the way to the left and right was the key. The following picture shows the issue, all why the scanning area was off. You might want to note these issues in the manual.

 

Attachment removed
Posted : 07/08/2019 4:04 am
Markus
(@markus-3)
New Member
RE: XYZ first calibration point not found. Frustrating.

Thanks for suggesting to check the X axis.

I had taken apart, cleaned, and reassembled the hot end. And I just couldn't figure out why afterwards, XYZ calibration no longer passed. It just didn't make much sense. Everything looked fine.

Until of course, I discovered that the zip ties for the hot end heater cartridge had shifted just a little bit. And that was enough for the heater cables to run into the XZ-frame. That meant, X origin was off by just a little bit. And that then resulted in XYZ calibration failing. The error message, of course, wasn't very telling unless you already knew what to look for. But your photo gave me the necessary hint.

Posted : 11/04/2020 10:52 pm
3DPrinterGuy=9134
(@3dprinterguy9134)
New Member
RE: XYZ first calibration point not found. Frustrating.

Hello,

Since November, I wasn't able to use my Original Prusa i3 MK3S printer (w/o the Multi-Material Upgrade) because of the technical issues regarding the XYZ and bed calibration.

1) I did all the suggestions from the forums regarding calibration of XYZ and the HeatBed and nothing works.

2) I lubricated all the bearings with sticky lubricant and the z-rods with regular lubricant.

3) I checked the P.I.N.D.A sensor in multiple positions and it works fine.

4) The self-check was successful.

5) The auto home runs successfully. 

6) I checked that the firmware of the Original Prusa i3 MK3S printer that we bought is 3.9.2-3594.

Yet still, the XYZ calibration fails before the detection of the 1st-bed calibration point.

Please advise. Thank you.

Posted : 15/02/2021 9:13 pm
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