martin.f3
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Re: P.I.N.D.A. probe misaligned

Mon Jul 04, 2016 5:39 pm

prusayo wrote:
christophe.p wrote:The extruder holder push the X-endstop with a small part. In the very first mk2 sent, there were some issue with sizes, I add to reprint it because the heater was not fitting well into the holder. There were some reports of users that had to add a little part of plastic on this small part to be able to properly trigger the endstop, and this may in some case add additional offset on the X-axis.
This printed part?
https://github.com/prusa3d/Orignal-Prus ... rriage.stl
Yeah, the little "L" part bottom right when you open that file online is the actual part that pushes the microswitch for x-end stop.
I couldn't move mine out much at all so I'm one of those who added some extra plastic to offset it a little bit, and now all 9 points are inside the circle and I'm printing happily :)

prusayo
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Re: P.I.N.D.A. probe misaligned

Mon Jul 04, 2016 11:11 pm

So I printed out the latest x-carriage stl from github and using digital calipers, do not see any difference in the length of the width containing the section that hits the endstop so I don't see how it would help to swap it out. The changelog for that piece is here:
https://github.com/prusa3d/Orignal-Prus ... 650a385550

I can't tell whether it's been made longer but the explanation is:
"Bigger bearing holes for easier assembly and fixed 2D manifold issues"

That doesn't seem like it's related to fixing the issue where the probe is off by 1-2 mm on the x-axis. It seems like a bit of work to swap it out as I'd have to cut off the zip ties and reinsert the black bands etc.

Based on the changelog can anyone confirm whether it would help with the probe being off slightly? The thing is, I'm not having a problem printing so maybe I'll just try the tape/cover trick to get the probe aligned perfectly or wait until the new 3.04 fw is available and deal with it that way instead.

prusayo
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Re: P.I.N.D.A. probe misaligned

Mon Jul 04, 2016 11:45 pm

Out of curiosity, I taped a 1mm pla rectangle to the L-section that hits the endstop and now the probe is directly in the circle. Calibration worked fine before, and it works fine now, so I don't see what the point was other than to have the probe perfectly in the circle.

wlg
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Re: P.I.N.D.A. probe misaligned

Tue Jul 05, 2016 8:23 am

Thank you Christophe for the awesome answer! (nice drawing from 'boulet' by the way ;)).
I had hints about the issues but the drawing along the explanation really helped me visualize it.
For that you need to unscrew the screws holding the endstop, push the endstop on the proper position, and while holding it, screw it again.
I tried to check that part but something bothered me. You cannot move the endstop that much and even though you can try to steal like 0.05mm of it, the screws will "bring it back" on track.
What I am trying to say is: the endstop (at least in my case) does not have the possibility to move in either direction of the x-axis. Apparently this was common in the first mk2? I will probably try the new beta FW in that case.

Thank you again for the great examples :)

wlg
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Re: P.I.N.D.A. probe misaligned

Thu Jul 07, 2016 6:30 pm

After upgrading to the 3.0.4 beta firmware... I now have a perfect bed calibration :).

This is a really really nice feature, I love it!

enrico.b3
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Re: P.I.N.D.A. probe misaligned

Tue Jul 11, 2017 8:00 am

Thanks Christophe for the very good explanation, but the heatbed of the MK2S kit has only circles at point 1 and 9.

What do you suggest to do for the P.I.N.D.A probe alignment?

Maybe you can do this:

1) Use "Auto home" from the LCD controller and do the adjustment you suggested, till the probe is in the middle of the circle at point 1.

2) Move the extruder on the X axis to the right, till the position of the expected point 3 (missing) circle. It can help, if you measure the distance of the point 9 circle and the right bed border and position the probe at point 3 at the same distance to the right border.

3) On point 3 measure the distance from the front bed border to the probe. If the distance is different from that on point 1, then do the adjustment you suggested.

4) Once that the the probe at the position of point 3 (missing) circle is correctly positioned (i.e. the distance from the probe to the front bed border is the same as in point 1 and the distance from the probe to the right bed border is the same as in point 9), move the extruder on the Y axis till the circle in point 9. If everything went well, the probe should be in the middle of the circle.

5) Use again "Auto home" to position the probe again on point 1 and check that the probe is still in the middle of the circle.

6) You have also to make sure that after all the adjustments, also the X-Y axis perpendicularity is still correct (see kit assembly manual chapter 7, step 19).

What do you think about this?

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