Autoleveling Doesnt seem to be working

I have a fully implemented autolevel bed that works great, but when it prints the z-axis doesnt seem to move at all except when changing layers.

I do the G28 and G29 before each print. Do I have to do anything else before Hitting print to actually implement it?

You shouldn't need to do anything else. Are you doing G28 and G29 manually before you hit print? If so, does your gcode contain an additional G28 at the beginning? Can you post the first chunk (20 lines or so) of gcode of one of the prints you have done?

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Quote
NewPerfection
You shouldn't need to do anything else. Are you doing G28 and G29 manually before you hit print? If so, does your gcode contain an additional G28 at the beginning? Can you post the first chunk (20 lines or so) of gcode of one of the prints you have done?

Sure!

; generated by Slic3r 1.0.0RC3 on 2014-03-06 at 18:56:09

; layer_height = 0.25
; perimeters = 3
; top_solid_layers = 3
; bottom_solid_layers = 3
; fill_density = 0.4
; perimeter_speed = 30
; infill_speed = 60
; travel_speed = 130
; nozzle_diameter = 0.5
; filament_diameter = 1.77
; extrusion_multiplier = 1
; perimeters extrusion width = 0.50mm
; infill extrusion width = 0.84mm
; solid infill extrusion width = 0.84mm
; top infill extrusion width = 0.84mm
; support material extrusion width = 0.50mm
; first layer extrusion width = 0.70mm

G21 ; set units to millimeters
M190 S50 ; wait for bed temperature to be reached
M104 S171 ; set temperature
G28 ; home all axes
G1 Z5 F5000 ; lift nozzle
M109 S171 ; wait for temperature to be reached
G90 ; use absolute coordinates
G92 E0
M82 ; use absolute distances for extrusion
M106 S255
G1 F1800.000 E-1.00000
G92 E0
G1 Z0.350 F7800.000
G1 X61.893 Y55.213 F7800.000
G1 E1.00000 F1800.000
G1 X62.593 Y54.583 E1.08802 F360.000
G1 X63.283 Y54.083 E1.16766
G1 X63.943 Y53.713 E1.23838
G1 X64.733 Y53.373 E1.31877
G1 X65.743 Y53.113 E1.41625
G1 X66.233 Y53.023 E1.46281
G1 X66.893 Y52.953 E1.52484
G1 X67.553 Y52.953 E1.58653
G1 X68.393 Y53.003 E1.66518
G1 X85.103 Y54.823 E3.23622
G1 X86.033 Y54.983 E3.32442
G1 X87.003 Y55.233 E3.41804
G1 X87.963 Y55.623 E3.51489
G1 X88.843 Y56.143 E3.61043
G1 X89.013 Y56.263 E3.62988
G1 X89.653 Y56.783 E3.70695
G1 X90.343 Y57.513 E3.80083
G1 X91.033 Y58.473 E3.91133
G1 X91.543 Y59.543 E4.02212

Edited 1 time(s). Last edit at 03/06/2014 07:34PM by kfootball15.

Is it the G90 command? Should it be G91 (use relative coordinates, rather then G90 - Use absolute coordinates)

Nope, unless you specifically have your slicer set to generate relative movements, you want the G90 there. There's no good reason to do this except for the extruder axis - [reprap.org] There's no real need to use relative extrusion either, though it does make some things easier, such as manually editing the gcode.

The problem is that your start gcode homes the printer again before printing (bold below). AFAIK, this resets the auto leveling. You need to do a G29 after that (underlined below). So, add that line to your Start G-code after the G28.

G21 ; set units to millimeters
M190 S50 ; wait for bed temperature to be reached
M104 S171 ; set temperature
G28 ; home all axes
G29 ; auto level Z
G1 Z5 F5000 ; lift nozzle
M109 S171 ; wait for temperature to be reached
G90 ; use absolute coordinates
G92 E0
M82 ; use absolute distances for extrusion
M106 S255
G1 F1800.000 E-1.00000
G92 E0
G1 Z0.350 F7800.000
G1 X61.893 Y55.213 F7800.000
G1 E1.00000 F1800.000
G1 X62.593 Y54.583 E1.08802 F360.000
G1 X63.283 Y54.083 E1.16766

Edit: Now you won't have to manually home and auto level your printer anymore. It will automatically do it at the start of each print after the heated bed warms up, which is the best time to do it anyways as a warm bed can vary in height slightly from cold depending on what it's made of.

Edited 1 time(s). Last edit at 03/06/2014 08:03PM by NewPerfection.

---

Help improve the RepRap wiki! Just click "Edit" in the top-right corner of the page and start typing. Anyone can edit the wiki!

Quote
NewPerfection
Nope, unless you specifically have your slicer set to generate relative movements, you want the G90 there. There's no good reason to do this except for the extruder axis - [reprap.org] There's no real need to use relative extrusion either, though it does make some things easier, such as manually editing the gcode.

The problem is that your start gcode homes the printer again before printing (bold below). AFAIK, this resets the auto leveling. You need to do a G29 after that (underlined below). So, add that line to your Start G-code after the G28.

G21 ; set units to millimeters
M190 S50 ; wait for bed temperature to be reached
M104 S171 ; set temperature
G28 ; home all axes
G29 ; auto level Z
G1 Z5 F5000 ; lift nozzle
M109 S171 ; wait for temperature to be reached
G90 ; use absolute coordinates
G92 E0
M82 ; use absolute distances for extrusion
M106 S255
G1 F1800.000 E-1.00000
G92 E0
G1 Z0.350 F7800.000
G1 X61.893 Y55.213 F7800.000
G1 E1.00000 F1800.000
G1 X62.593 Y54.583 E1.08802 F360.000
G1 X63.283 Y54.083 E1.16766

Edit: Now you won't have to manually home and auto level your printer anymore. It will automatically do it at the start of each print after the heated bed warms up, which is the best time to do it anyways as a warm bed can vary in height slightly from cold depending on what it's made of.

I feel stupid!

Thanks so so much!!!