Davinci 2.0 upgrade

I upgraded my davinci 2.0 to arduino software. My problem is plots start 30 mm in from the edge of the bed. Where is the variable to move the extruder back?

It's somewhere in the unspecified arduino software.

And to think I thought this was a helpful forum

How would you expect someone to "just know" what Arduino software you're using?

Point taken, I am using version 1.8.0. I know it's in the config.h file just can't find where