Quote Originally Posted by cropwell View Post
First of all the Prusa Homes by detecting motor stall current, so it has a reference point for a start.

You need a reference point, otherwise your machine does not know where it is. So Home switches provide that. and set machine 0,0,0. If you have a fixture (jig) for the workpiece, you can then use work offsets to relativise your Gcode to the work. This gives you repeatability.

BUT you don't have to do it that way, especially for one-off machining. You can set x and Y zeroes manually above the workpiece and then touch-off against the material top (manually or with a touch plate and macro!). So your Gcode then operates as is relative to the 0,0,0 you have set on the machine.

Whether your system is open or closed loop is irrelevant, as you still need your start reference.
I see, and i begin to get it... Thanks!