3D Touch Calibration - Can't move to negative Z position

[SarenT]

Hi,

I am trying to calibrate my 3D touch sensor, however I am stuck at the step, where I am supposed to manually move nozzle closer to the bed, until a folded paper barely fits in between. The problem is, that I can move Z to negative numbers. It stops at 0. Wiki page doesn't say anything about this. What am I missing? Should I allow negative Z values with a g-code command? (G1 S1/G1 S0?)

Thanks!

[William]

You should tell us which type of printer you are using, and upload your firmware, which is good for solving the issue

[SarenT]

Of course, sorry for missing that. I have Prusa i3 Pro W. I have managed to improvise it by setting current Z value from 0 to 3. Then I was able to move down. Let's say until 0,4. So I set the M851 Z-2.6. Wiki document assumes that you can go to negative Z positions, which wasn't the case for my prusa i3 pro W. Another confusion was for me, that I assumes after setting this G28 would go move the nozzle as close as printing position. Which wasn't the case nozzle always moves away during G28. Only during print it performs a multi position touch and the nozzle moves close to the bed to start printing.

[William]

You should change these lines(Please modify your firmware according to actual condition， this is an unmodified firmware, just for example only)

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