When i was farming for sword, i kept spaaning into earth until i could find a spinmetal patch in the steppes close to the mothyards, pick it up a jump on sparrow and fly to mothyards. Hopefully get lucky and one will be right where you enter mothyards. Pick it up and fly back to steppes... i got lucky and was able to bounce back and fourth between the 2 for about 20 min and got all i needed.