Hiʻona 1:Hoʻopili ʻia ka rail sliding a me ka sliding block i kekahi i kekahi ma o nā pōpō, no laila ua liʻiliʻi ka haʻalulu, kahi kūpono no nā lako me nā koi pololei.
Hiʻona 2:Ma muli o ka pili ʻana o ka point-to-surface, liʻiliʻi loa ke kūpaʻa frictional, a hiki ke hana ʻia nā neʻe maikaʻi e hoʻokō i kahi kūlana kiʻekiʻe o nā mea hoʻokele, etc.