Thupi lochotsa madzi limapangidwa ndi screw axis yokhala ndi ma plate omangira ndi osuntha omwe akulumikizana, popeza m'mimba mwake wa screw axis ndi waukulu kuposa plate yosuntha, plate yosunthayo imachita zozungulira ndi screw axis kuti isatseke. Malo pakati pa ma plate omangira ndi osuntha amakhala ochepa pang'onopang'ono motsatira njira yotulutsira matope. Pambuyo pa kuchuluka kwa mphamvu yokoka, matope amatengedwa kupita ku zigawo za madzi osowa, ndipo amachotsa madzi pansi pa kupanikizika kwamkati kwa plate yotulukira.