Saboda kusurwar helix, ainihin kusurwar rake na famfo zai karu yayin da kusurwar helix ya karu.Kwarewa ta gaya mana: Don sarrafa karafa na ƙarfe, kusurwar helix ya kamata ya zama ƙarami, gabaɗaya a kusa da digiri 30, don tabbatar da ƙarfin haƙoran haƙora da taimakawa tsawaita rayuwar famfo.Don sarrafa karafan da ba na ƙarfe ba kamar jan karfe, aluminum, magnesium, da zinc, kusurwar helix ya kamata ya fi girma, wanda zai iya zama kusan digiri 45, kuma yanke ya fi kaifi, wanda ke da kyau don cire guntu.