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Nathan
(@nathan-5)
Trusted Member
Large Z Offset

Last night I kept running into a problem with the printer failing during the z offset part of the calibration. It would go through the wizard, fine tune all the points and then ask my to insert filament. I would do that and then when it would try to home the 9 points to begin the live adjust z print it kept failing on the second or third spot. I had to keep lowering the pinda probe to get it to successfully detect all 9 points. I lowered it to about half the height of the recommended zip tie and now my z adjust value is over -.900 . On my mk2 I never went over -.350. My XYZ calibration reported slightly skewed if that matters here. Is it ok to have the pinda so low and the z adjust so high or should I try something else to allow the pinda to be at the correct height and still detect all 9 points?

Thanks,
Nathan

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Posted : 25/01/2018 4:25 pm
karim.b
(@karim-b)
New Member
Re: Large Z Offset

Hi Nathan,
Instead of using a zip tie to set the height of my Pinda probe, I used a business card that was .48mm thick. I then needed to set my live z height to 1.307!

That was the only way I was able to get a good first layer.

I don't know if this means that my Pinda probe is more/less sensitive than it should be, but these are the settings that work for me.

Posted : 25/01/2018 4:56 pm
Bill
 Bill
(@bill-3)
Estimable Member
Re: Large Z Offset


Last night I kept running into a problem with the printer failing during the z offset part of the calibration. It would go through the wizard, fine tune all the points and then ask my to insert filament. I would do that and then when it would try to home the 9 points to begin the live adjust z print it kept failing on the second or third spot. I had to keep lowering the pinda probe to get it to successfully detect all 9 points. I lowered it to about half the height of the recommended zip tie and now my z adjust value is over -.900 . On my mk2 I never went over -.350. My XYZ calibration reported slightly skewed if that matters here. Is it ok to have the pinda so low and the z adjust so high or should I try something else to allow the pinda to be at the correct height and still detect all 9 points?

Thanks,
Nathan

What do you mean "it kept failing on the second or third spot"? Do you mean during the automatic leveling routine the printer goes through before every print? Or do you mean during the live Z print of filament? You should not have to adjust the live Z during the 9 point leveling routine. In fact, I am fairly certain that you cannot adjust live Z setting during this routine (as I recall live Z adjust will not show up in the menu until the printer starts to print the purge strip). Unless you mean you are manipulating the probe itself?

I would like to try and help, but I am not sure what you have going on. Also, do not obsess over the live Z number. As I learned and many others have said, every printer has a different number and what the actual number is means nothing. As long as you are getting a good first layer, the actual number is insignificant.

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Posted : 25/01/2018 5:10 pm
Nathan
(@nathan-5)
Trusted Member
Topic starter answered:
Re: Large Z Offset

It would fail during the 9 point level it does before each print, in this case the print was the z-adjust calibration print. I had to keep lowering the pinda and redoing the xyz calibration until finally it was able to find all 9 points. After which I had to live adjust z to -.920 in order for the filament to stick to the bed.

Thanks,
Nathan

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Posted : 25/01/2018 5:34 pm
paul.m27
(@paul-m27)
Honorable Member
Re: Large Z Offset


It would fail during the 9 point level it does before each print, in this case the print was the z-adjust calibration print. I had to keep lowering the pinda and redoing the xyz calibration until finally it was able to find all 9 points. After which I had to live adjust z to -.920 in order for the filament to stick to the bed.

Thanks,
Nathan

What do you mean by "fail"? What message came up on the screen, or did it hit the bed, or just stop?

Posted : 25/01/2018 6:57 pm
Nathan
(@nathan-5)
Trusted Member
Topic starter answered:
Re: Large Z Offset

The message was something like "Failed to detect bed point, waiting for reset" The nozzle did not touch the bed.

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Posted : 25/01/2018 7:31 pm
Bill
 Bill
(@bill-3)
Estimable Member
Re: Large Z Offset

That is odd. I do not recall anyone posting an error quite like this and I have been following the forums for almost a year. If this keeps happening my guess would be a faulty thermistor in the pinda probe or a short in the probe itself. Enough to pass the test, but giving faulty readings. I would check two things first...

One, see if you have a short in the thermistor wire or pinda wires. Second, take an Ohm measurement of the thermistor at room temperature and make sure the reading falls within the accepted range (what that is, you will have to ask someone more knowlegable than me). You could also try this test... http://help.prusa3d.com/l/en/article/3tSXh6nWJd-pinda-probe-testing

EDIT...

After more consideration, I would try the test in the link first. If you are getting values outside of thre prescribed >.02 value, I would report your findings to support and request a new probe. I was not aware of this test until I searched after seing your problem. Ran the test on my printer. Quite nice to have this data to see the actual measurement reading from the probe.

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Posted : 25/01/2018 10:29 pm
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