<<Revamped M565 Z Offset. Set it and forget it!>>

Well it appears there is some success with this issue. The Marlin developers have agreed to have both positive and negative values for the Z Probe Offset and will update the LCD to allow +/- offset values.

Scroll to the bottom of this issue thread. .

https://github.com/MarlinFirmware/Marlin/issues/1682

The changes will be in pull request #1700 - not sure when the changes will be released in a stable version though.

More generally it appears to be a good time to engage with the developers and influence what goes into Marlin. So far the Filament Monitor and +/- Z Probe offset are being added. Some good progress is also being made getting the "filament consumed" to be calculated in Marlin and displayed on the LCD.

 

The smallest increment is based on the number of steps involved to achieve 1 mm of travel. So if it's 80 then the inverse would be the increment you could use (1/80 mm ~ 0.0125 mm). Personally, I ignore every digit beyond two right of the decimal point. Our Robo's simply do not have that much precision to make any difference, and 2 decimal places gives you 100 choices for z offset.

This is an extremely simplified explanation.

 

Don't over think it. Just put it in your startup GCode block and be done with it.

G28;
M565 -Zx.xx; your offset number
G29;