Njira yowotcherera ya arc yokhala ndi mbali ziwiri imatha kuzindikira kuwotcherera pamalo abwino kwambiri, zomwe sizili zophweka kukhala ndi zolakwika monga kusalongosoka, kupatuka kwa kuwotcherera ndi kulowa kosakwanira, ndipo ndikosavuta kuwongolera mtundu wa kuwotcherera.