First layer print height .2mm too high

[brant81]

I think something in my startup code is messing up my first layer height. The machine controls are showing that it is printing at .38 which seems to be accurate for it's current height off the bed, but it should be .18. I'm printing .2 layer height and the first layer settings are set to print at 90% of the layer height.

I have a Robo3D R1 with autolevel. I don't have skirt/brim enabled, so I have a bit of G-Code to wipe the nozzle (which doesn't work super well actually). Here's my startup G-Code:

Code: Select all

G28 ; home all axes
G1 Z5 F5000 ; lift Z by 5mm
M565 Z-1.3 ; set the offset for auto-leveling mechanism
G29 ; run auto-level

G1 Z2; RAISE Z-AXIS TO 2MM
M84; KILL MOTORS
G92 E0; ZERO EXTRUDER

M140 S[bed0_temperature]
M190 S[bed0_temperature]
M104 S[extruder0_temperature]
M109 S[extruder0_temperature]

G1 X5 Y250; MOVE CLOSE TO END OF Y AXIS
G1 Z.2; LOWER Z-AXIS TO .2 MM
G1 F1500; SET MOVE RATE SLOW
G1 X220 E15; CLEAR FILAMENT
G1 Z2; RAISE Z-AXIS TO 2MM
G92 E0; ZERO EXTRUDER

So why does it print the first layer at .38 instead of .18? Shouldn't the printer know what height it's at? The app is reporting the height correctly.

[JoeJ]

Do you have gcode offsets set on the G-Code tab of your FFF settings? Check the z-axis gcode offset, since that you affect the position of the first layer as well