Z-probe Creating Incorrect Results

Hey all, 

Been having some very strange results with my z-probe and was wondering if anyone could shed some light on the issue. I was having no luck with G32. Today I'd had enough with fighting G32. I used G33 to create a bump map, the results were of course incorrect so I then redid each point by hand with the paper method. I'm getting very good first layers now, but this isn't really a solution because if I ever change anything I will have to go through this process again. At very least I have some nice data to go over, maybe that will lead to a solution. Thank you to anyone who tries to help.

Printer: DIY Delta (Kossel Mini derivative)
Firmware: Repetier 0.92.9
Board: Arduino Mega + Ramps

I'll link to my EEPROM settings, my config.h, and the results from redoing the distortion map by hand. 



Comments

  • Forgot to mention, I am using an inductive probe, not sure if it's relevant but here's the model:

    uxcell DC 6-36V NPN NO 3-wire 4mm Noncontact Inductive Proximity Sensor Switch LJ12A3-4-Z/BX

  • These are the bump map before and after results for anyone who doesn't want to use g drive, Thew ones labeled original came from the z-probe, the second set of results was me redoing each point with the paper method.



    ORIGINAL



    ORIGINAL


    18:30:29.400 : G33 X-50.00 Y-50.00 Z-0.388
    18:30:29.400 : G33 X-50.00 Y-33.34 Z-0.237
    18:30:29.404 : G33 X-50.00 Y-16.68 Z-0.137
    18:30:29.405 : G33 X-50.00 Y-0.01 Z-0.094
    18:30:29.409 : G33 X-50.00 Y16.65 Z-0.125
    18:30:29.409 : G33 X-50.00 Y33.31 Z-0.169
    18:30:29.409 : G33 X-50.00 Y49.98 Z-0.150

    18:30:29.413 : G33 X-33.34 Y-50.00 Z-0.094
    18:30:29.413 : G33 X-33.34 Y-33.34 Z-0.281
    18:30:29.417 : G33 X-33.34 Y-16.68 Z-0.200
    18:30:29.417 : G33 X-33.34 Y-0.01 Z-0.194
    18:30:29.417 : G33 X-33.34 Y16.65 Z-0.187
    18:30:29.421 : G33 X-33.34 Y33.31 Z-0.169
    18:30:29.421 : G33 X-33.34 Y49.98 Z-0.125

    18:30:29.425 : G33 X-16.68 Y-50.00 Z0.256
    18:30:29.425 : G33 X-16.68 Y-33.34 Z-0.263
    18:30:29.425 : G33 X-16.68 Y-16.68 Z-0.206
    18:30:29.429 : G33 X-16.68 Y-0.01 Z-0.225
    18:30:29.429 : G33 X-16.68 Y16.65 Z-0.244
    18:30:29.434 : G33 X-16.68 Y33.31 Z-0.219
    18:30:29.434 : G33 X-16.68 Y49.98 Z-0.163

    18:30:29.434 : G33 X-0.01 Y-50.00 Z0.256
    18:30:29.437 : G33 X-0.01 Y-33.34 Z-0.075
    18:30:29.437 : G33 X-0.01 Y-16.68 Z-0.106
    18:30:29.441 : G33 X-0.01 Y-0.01 Z-0.150
    18:30:29.442 : G33 X-0.01 Y16.65 Z-0.206
    18:30:29.442 : G33 X-0.01 Y33.31 Z-0.219
    18:30:29.446 : G33 X-0.01 Y49.98 Z-0.219

    18:30:29.446 : G33 X16.65 Y-50.00 Z0.719
    18:30:29.446 : G33 X16.65 Y-33.34 Z0.181
    18:30:29.450 : G33 X16.65 Y-16.68 Z0.088
    18:30:29.450 : G33 X16.65 Y-0.01 Z-0.006
    18:30:29.454 : G33 X16.65 Y16.65 Z-0.088
    18:30:29.454 : G33 X16.65 Y33.31 Z-0.169
    18:30:29.454 : G33 X16.65 Y49.98 Z-0.200

    18:30:29.458 : G33 X33.31 Y-50.00 Z0.913
    18:30:29.458 : G33 X33.31 Y-33.34 Z0.463
    18:30:29.462 : G33 X33.31 Y-16.68 Z0.312
    18:30:29.462 : G33 X33.31 Y-0.01 Z0.169
    18:30:29.462 : G33 X33.31 Y16.65 Z0.075
    18:30:29.466 : G33 X33.31 Y33.31 Z-0.050
    18:30:29.466 : G33 X33.31 Y49.98 Z-0.156
    18:30:29.470 : G33 X49.98 Y-50.00 Z1.131

    18:30:29.470 : G33 X49.98 Y-33.34 Z0.856
    18:30:29.470 : G33 X49.98 Y-16.68 Z0.556
    18:30:29.474 : G33 X49.98 Y-0.01 Z0.369
    18:30:29.474 : G33 X49.98 Y16.65 Z0.206
    18:30:29.478 : G33 X49.98 Y33.31 Z0.088
    18:30:29.478 : G33 X49.98 Y49.98 Z-0.069


    EACH POINT DONE BY HAND


    21:07:34.387 : G33 X-50.00 Y-50.00 Z-0.169
    21:07:34.387 : G33 X-50.00 Y-33.34 Z-0.088
    21:07:34.387 : G33 X-50.00 Y-16.68 Z-0.038
    21:07:34.391 : G33 X-50.00 Y-0.01 Z-0.038
    21:07:34.391 : G33 X-50.00 Y16.65 Z-0.031
    21:07:34.395 : G33 X-50.00 Y33.31 Z0.000
    21:07:34.395 : G33 X-50.00 Y49.98 Z0.000

    21:07:34.395 : G33 X-33.34 Y-50.00 Z-0.169
    21:07:34.399 : G33 X-33.34 Y-33.34 Z-0.125
    21:07:34.399 : G33 X-33.34 Y-16.68 Z-0.100
    21:07:34.403 : G33 X-33.34 Y-0.01 Z-0.069
    21:07:34.403 : G33 X-33.34 Y16.65 Z-0.050
    21:07:34.403 : G33 X-33.34 Y33.31 Z-0.038
    21:07:34.407 : G33 X-33.34 Y49.98 Z0.000

    21:07:34.407 : G33 X-16.68 Y-50.00 Z-0.125
    21:07:34.411 : G33 X-16.68 Y-33.34 Z-0.100
    21:07:34.411 : G33 X-16.68 Y-16.68 Z-0.044
    21:07:34.411 : G33 X-16.68 Y-0.01 Z-0.044
    21:07:34.415 : G33 X-16.68 Y16.65 Z-0.044
    21:07:34.415 : G33 X-16.68 Y33.31 Z-0.044
    21:07:34.419 : G33 X-16.68 Y49.98 Z0.000

    21:07:34.419 : G33 X-0.01 Y-50.00 Z-0.156
    21:07:34.419 : G33 X-0.01 Y-33.34 Z-0.050
    21:07:34.423 : G33 X-0.01 Y-16.68 Z-0.063
    21:07:34.423 : G33 X-0.01 Y-0.01 Z-0.119
    21:07:34.423 : G33 X-0.01 Y16.65 Z-0.056
    21:07:34.427 : G33 X-0.01 Y33.31 Z-0.106
    21:07:34.427 : G33 X-0.01 Y49.98 Z-0.119

    21:07:34.431 : G33 X16.65 Y-50.00 Z0.000
    21:07:34.431 : G33 X16.65 Y-33.34 Z-0.075
    21:07:34.431 : G33 X16.65 Y-16.68 Z-0.056
    21:07:34.436 : G33 X16.65 Y-0.01 Z-0.056
    21:07:34.436 : G33 X16.65 Y16.65 Z-0.050
    21:07:34.440 : G33 X16.65 Y33.31 Z-0.088
    21:07:34.440 : G33 X16.65 Y49.98 Z-0.088

    21:07:34.440 : G33 X33.31 Y-50.00 Z0.119
    21:07:34.444 : G33 X33.31 Y-33.34 Z0.019
    21:07:34.444 : G33 X33.31 Y-16.68 Z-0.025
    21:07:34.448 : G33 X33.31 Y-0.01 Z-0.025
    21:07:34.448 : G33 X33.31 Y16.65 Z-0.056
    21:07:34.448 : G33 X33.31 Y33.31 Z-0.038
    21:07:34.452 : G33 X33.31 Y49.98 Z-0.056

    21:07:34.452 : G33 X49.98 Y-50.00 Z1.131
    21:07:34.456 : G33 X49.98 Y-33.34 Z0.125
    21:07:34.456 : G33 X49.98 Y-16.68 Z0.019
    21:07:34.456 : G33 X49.98 Y-0.01 Z-0.056
    21:07:34.460 : G33 X49.98 Y16.65 Z-0.050
    21:07:34.460 : G33 X49.98 Y33.31 Z-0.050
    21:07:34.464 : G33 X49.98 Y49.98 Z-0.050

  • Hope heater was off when measuring. Heater creates inductive field influencing probe results.

    Futhermore your z probe height might be off 0.1-0.3mm as that seems the range of error.

    You should test repeatablility of z probe results. So at one point call G30 several times. SHould return the same result +/-0.02mm. If not your probe is not good or not working at the best range.
  • Repeatability is within acceptable range. However my heated bed was on, seems pretty obvious in hindsight that running what is essentially a giant coil under my sensor was a bad idea. 

    Thank you so much for the response!! That was a really stupid mistake on my part, I just assumed that the bed would warp a little when heated so I should preheat first so this gets compensated for.
  • So I tried again without my heated bed turned on, and you were right It was definitely affecting my values. However it is still not correct. I'm not really sure where to go from here.
  • What pin is your probe connected to?
    Is it connected via a resistor voltage divider or a reverse bias diode?

  • I have my probe connected to zmin. And I have the probe switching the 5v signal that normally comes from the endstop. It looks like this
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