image http://upload.wikimedia.org/wikipedia/commons/thumb/e/eb/English_length_units_graph.svg/605px-English_length_units_graph.svg.png style="width:300px"
G21 G-code
G21 means “all moves starting now have their units specified in millimeters ( metric units )”.
G21's evil twin is G20, which means “all moves starting now have their units specified in inches ( imperial units )”.
An inch is 25.4 millimeters.
G21 is the default when Smoothie starts.
Format
The command is used as such :
G21
Which means : units are now metric until another G-code changes it ( modal command )
Parameters
No parameters.
