Hi!
I was having troubles calibrating the bed auto leveling so I made a simple test and find what I think is a problem.
The test (first steps are from Marlin documentation) :
a) I made a small mark in the bed with a marker/felt-tip pen.
b) I placed the hotend tip as *exactly* as possible on the mark, touching the bed. I raised the hotend 0.1mm and zero all axis (G92 X0 Y0 Z0);
d) I raised the hotend 40mm, lowered the Z probe (Z-Endstop) and placed it just on that mark by moving X, Y and Z;
e) I lowered the Z in 0.1mm steps, with the probe always touching the mark until I heared the "click";
f) I return the hotend tip to the small mark
g) I performed a M114
I was expecting the M114 to return: X:0.00 Y:0.00 Z:0.00 E:0.00 Count X: 0.00 Y:0.00 Z:0.00
but it wasn't the case. Here are the results I obtained (I run this test 3 times)
X:0.00 Y:0.00 Z:-4.60 E:0.00 Count X: 0.00 Y:0.00 Z:-0.03
X:0.00 Y:0.00 Z:-8.40 E:0.00 Count X: 0.00 Y:0.00 Z:0.01
X:0.00 Y:0.00 Z:-8.80 E:0.00 Count X: 0.00 Y:0.00 Z:-0.02
The printer is a homemade Prusa i3 with a RAMPS 1.4 and the latest Marlin software. I am using Pronterface for Mac (printrun 2014.08.01)
The Z screw is a M5 and I made the calculation using Prusa Calculator: [
prusaprinters.org]
any Idea of what is wrong?
