Merge pull request #888 from whosawhatsis/quick_home

Speed up QUICK_HOME feedrate for diagonal move

Marlin/Marlin_main.cpp

@@ -1287,6 +1287,11 @@ void process_commands()
         feedrate = homing_feedrate[X_AXIS];
         if(homing_feedrate[Y_AXIS]<feedrate)
           feedrate = homing_feedrate[Y_AXIS];
+        if (max_length(X_AXIS) > max_length(Y_AXIS)) {
+          feedrate *= sqrt(pow(max_length(Y_AXIS) / max_length(X_AXIS), 2) + 1);
+        } else {
+          feedrate *= sqrt(pow(max_length(X_AXIS) / max_length(Y_AXIS), 2) + 1);
+        }
         plan_buffer_line(destination[X_AXIS], destination[Y_AXIS], destination[Z_AXIS], destination[E_AXIS], feedrate/60, active_extruder);
         st_synchronize();