›

G33 distortion correction

mars0120mars0120
in Repetier-Firmware
I am having trouble with distortion correction.  I have my Z axis height and bed level so that I can print fairly well without any correction, but larger prints start to show the distortion and I have bed adhesion problems.  

When I run G33 I get a distortion map copied below..  

When I attempt to print the nozzle attempts to print several mm above the print bed. When I try to verify the distortion correction manually with the paper shim the nozzle is either 1mm above the bed or it crashes into the print bed. It is not even consistent between homing for the same distortion map.  It seems like when the print head gets to 0.5mm above the print head it just goes crazy.  

I must have something wrong.  Can you help me set this up?

I am sure the Z probe height is -5.7.  I am sure the z max distance is 463.8

00:47:26.421 : Z correction disabled
00:47:30.757 : Z-probe:-1.15 X:-50.00 Y:100.00
00:47:33.043 : Z-probe:-1.01 X:0.00 Y:100.00
00:47:35.375 : Z-probe:-0.94 X:50.00 Y:100.00
00:47:38.531 : Z-probe:-1.12 X:-100.00 Y:50.00
00:47:40.829 : Z-probe:-1.02 X:-50.00 Y:50.00
00:47:43.135 : Z-probe:-1.01 X:0.00 Y:50.00
00:47:45.453 : Z-probe:-0.92 X:50.00 Y:50.00
00:47:47.841 : Z-probe:-0.79 X:100.00 Y:50.00
00:47:51.405 : Z-probe:-0.99 X:-100.00 Y:0.00
00:47:53.744 : Z-probe:-0.97 X:-50.00 Y:0.00
00:47:56.077 : Z-probe:-0.95 X:0.00 Y:0.00
00:47:58.424 : Z-probe:-0.91 X:50.00 Y:0.00
00:48:00.778 : Z-probe:-0.89 X:100.00 Y:0.00
00:48:04.351 : Z-probe:-0.89 X:-100.00 Y:-50.00
00:48:06.699 : Z-probe:-0.95 X:-50.00 Y:-50.00
00:48:09.035 : Z-probe:-0.97 X:0.00 Y:-50.00
00:48:11.390 : Z-probe:-0.92 X:50.00 Y:-50.00
00:48:13.722 : Z-probe:-0.95 X:100.00 Y:-50.00
00:48:16.940 : Z-probe:-0.89 X:-50.00 Y:-100.00
00:48:19.311 : Z-probe:-0.92 X:0.00 Y:-100.00
00:48:21.663 : Z-probe:-0.96 X:50.00 Y:-100.00
00:48:23.581 : Info:Distortion correction matrix:
00:48:23.581 : 902, 892, 881, 875, 862
00:48:23.581 : 890, 882, 881, 874, 863
00:48:23.581 : 879, 878, 876, 873, 871
00:48:23.581 : 871, 876, 878, 874, 876
00:48:23.597 : 865, 871, 874, 877, 880
00:48:23.597 : Distortion correction at px:-100.00 py:-100.00 zCoorection:10.812
00:48:23.597 : Distortion correction at px:-100.00 py:-50.00 zCoorection:10.887
00:48:23.597 : Distortion correction at px:-100.00 py:0.00 zCoorection:10.987
00:48:23.597 : Distortion correction at px:-100.00 py:50.00 zCoorection:11.125
00:48:23.597 : Distortion correction at px:-100.00 py:100.00 zCoorection:11.275
00:48:23.597 : Distortion correction at px:-50.00 py:-100.00 zCoorection:10.887
00:48:23.612 : Distortion correction at px:-50.00 py:-50.00 zCoorection:10.950
00:48:23.612 : Distortion correction at px:-50.00 py:0.00 zCoorection:10.975
00:48:23.612 : Distortion correction at px:-50.00 py:50.00 zCoorection:11.025
00:48:23.612 : Distortion correction at px:-50.00 py:100.00 zCoorection:11.150
00:48:23.612 : Distortion correction at px:0.00 py:-100.00 zCoorection:10.925
00:48:23.612 : Distortion correction at px:0.00 py:-50.00 zCoorection:10.975
00:48:23.628 : Distortion correction at px:0.00 py:0.00 zCoorection:10.950
00:48:23.628 : Distortion correction at px:0.00 py:50.00 zCoorection:11.012
00:48:23.628 : Distortion correction at px:0.00 py:100.00 zCoorection:11.012
00:48:23.628 : Distortion correction at px:50.00 py:-100.00 zCoorection:10.963
00:48:23.628 : Distortion correction at px:50.00 py:-50.00 zCoorection:10.925
00:48:23.628 : Distortion correction at px:50.00 py:0.00 zCoorection:10.913
00:48:23.628 : Distortion correction at px:50.00 py:50.00 zCoorection:10.925
00:48:23.643 : Distortion correction at px:50.00 py:100.00 zCoorection:10.937
00:48:23.643 : Distortion correction at px:100.00 py:-100.00 zCoorection:11.000
00:48:23.643 : Distortion correction at px:100.00 py:-50.00 zCoorection:10.950
00:48:23.643 : Distortion correction at px:100.00 py:0.00 zCoorection:10.887
00:48:23.659 : Distortion correction at px:100.00 py:50.00 zCoorection:10.788
00:48:23.660 : Distortion correction at px:100.00 py:100.00 zCoorection:10.775
00:48:23.665 : Z correction enabled

Comments

  • RepetierRepetier
    Are we talking about a delta printer?

    Anyway -5.7 mm z probe height sound very wrong. That would mean when your z probe triggers, the extruder is 5.7 below bed level. With FSR/springs small negative numbers are possible but 5.7mm is extreme.

    Furthermore G33 L0 should show a distortion matrix that swings around 0 not in range of 10-11mm. It is a correction of zero.

    Also make sure that z home goes back from z max a few mm, on deltas maybe even 20mm to prevent crashing into endstops.

    So first check eeprom and check bed coating is 0, so we have not to watch for that. Disable distortion and do autolevel G32 S2. If you then go to G0 X0 Y0 Z0 your extruder nozzle should be very close to the bed. Better to go first to Z20 and then slowly lower as we are searching correct height. Once you touch bed the z must be added/subtracted from z probe height. Only once G32 S2 creates satisfying results you can run G33. Later on you can modify heights With G33 Xpos Ypos Zcorrection if it somewhere not as expected, especially with deltas where points were extrapolated to get a bigger circle.
  • mars0120mars0120
    Yes it is a delta.  

    My probe triggers when the print nozzle is 5.7 mm above the print bed.  I had the sign wrong on that field.  Below is the more appropriate distortion correction matrix.

    The nozzle no longer goes crazy but it still rides too high above the build plate.  If I disable distortion correction the printer works fine for prints around 100mm square in the center of the plate.  With distortion correction on the nozzle is always too high. It won't even print a 10mm square.

    Do I have to do G32 S2 prior to G33?  I have my print bed very level  manually.  Will a manual bed level not work?

    09:53:26.883 : Z correction disabled
    09:53:32.218 : Z-probe:15.43 X:-50.00 Y:100.00
    09:53:36.558 : Z-probe:15.48 X:0.00 Y:100.00
    09:53:40.941 : Z-probe:15.63 X:50.00 Y:100.00
    09:53:46.167 : Z-probe:15.40 X:-100.00 Y:50.00
    09:53:50.499 : Z-probe:15.55 X:-50.00 Y:50.00
    09:53:54.887 : Z-probe:15.57 X:0.00 Y:50.00
    09:53:59.289 : Z-probe:15.65 X:50.00 Y:50.00
    09:54:03.739 : Z-probe:15.79 X:100.00 Y:50.00
    09:54:09.357 : Z-probe:15.48 X:-100.00 Y:0.00
    09:54:13.744 : Z-probe:15.60 X:-50.00 Y:0.00
    09:54:18.132 : Z-probe:15.54 X:0.00 Y:0.00
    09:54:22.521 : Z-probe:15.64 X:50.00 Y:0.00
    09:54:26.945 : Z-probe:15.71 X:100.00 Y:0.00
    09:54:32.570 : Z-probe:15.55 X:-100.00 Y:-50.00
    09:54:36.942 : Z-probe:15.52 X:-50.00 Y:-50.00
    09:54:41.310 : Z-probe:15.50 X:0.00 Y:-50.00
    09:54:45.696 : Z-probe:15.59 X:50.00 Y:-50.00
    09:54:50.101 : Z-probe:15.66 X:100.00 Y:-50.00
    09:54:55.374 : Z-probe:15.55 X:-50.00 Y:-100.00
    09:54:59.746 : Z-probe:15.52 X:0.00 Y:-100.00
    09:55:04.127 : Z-probe:15.52 X:50.00 Y:-100.00
    09:55:07.065 : Info:Distortion correction matrix:
    09:55:07.065 : 28, 22, 18, 6, -9
    09:55:07.081 : 24, 12, 10, 4, -7
    09:55:07.081 : 18, 8, 13, 5, -1
    09:55:07.081 : 12, 14, 16, 9, 3
    09:55:07.081 : 8, 12, 14, 14, 10
    09:55:07.081 : Distortion correction at px:-100.00 py:-100.00 zCoorection:0.100
    09:55:07.081 : Distortion correction at px:-100.00 py:-50.00 zCoorection:0.150
    09:55:07.081 : Distortion correction at px:-100.00 py:0.00 zCoorection:0.225
    09:55:07.081 : Distortion correction at px:-100.00 py:50.00 zCoorection:0.300
    09:55:07.081 : Distortion correction at px:-100.00 py:100.00 zCoorection:0.350
    09:55:07.096 : Distortion correction at px:-50.00 py:-100.00 zCoorection:0.150
    09:55:07.096 : Distortion correction at px:-50.00 py:-50.00 zCoorection:0.175
    09:55:07.096 : Distortion correction at px:-50.00 py:0.00 zCoorection:0.100
    09:55:07.096 : Distortion correction at px:-50.00 py:50.00 zCoorection:0.150
    09:55:07.096 : Distortion correction at px:-50.00 py:100.00 zCoorection:0.275
    09:55:07.096 : Distortion correction at px:0.00 py:-100.00 zCoorection:0.175
    09:55:07.112 : Distortion correction at px:0.00 py:-50.00 zCoorection:0.200
    09:55:07.112 : Distortion correction at px:0.00 py:0.00 zCoorection:0.163
    09:55:07.112 : Distortion correction at px:0.00 py:50.00 zCoorection:0.125
    09:55:07.112 : Distortion correction at px:0.00 py:100.00 zCoorection:0.225
    09:55:07.112 : Distortion correction at px:50.00 py:-100.00 zCoorection:0.175
    09:55:07.112 : Distortion correction at px:50.00 py:-50.00 zCoorection:0.113
    09:55:07.112 : Distortion correction at px:50.00 py:0.00 zCoorection:0.063
    09:55:07.128 : Distortion correction at px:50.00 py:50.00 zCoorection:0.050
    09:55:07.128 : Distortion correction at px:50.00 py:100.00 zCoorection:0.075
    09:55:07.128 : Distortion correction at px:100.00 py:-100.00 zCoorection:0.125
    09:55:07.128 : Distortion correction at px:100.00 py:-50.00 zCoorection:0.038
    09:55:07.128 : Distortion correction at px:100.00 py:0.00 zCoorection:-0.012
    09:55:07.128 : Distortion correction at px:100.00 py:50.00 zCoorection:-0.088
    09:55:07.146 : Distortion correction at px:100.00 py:100.00 zCoorection:-0.113
    09:55:07.150 : Z correction enabled

  • RepetierRepetier
    Your problem is in deed manual calibration. In this case G33 compensates for bumps + difference to G32 S2 and that is apperently 0.1mm or so on average. This also means your z probe height is 0.1mm too high. G32 S2 must be the height you'd also set manually. Then do G32 S2 and G33. If your in total a bit too high/low you could adjust using bed coating to go up or down in total.
Sign In or Register to comment.