Luffing mechanism yog lub luag haujlwm tseem ceeb ntawm jib crane, uas yog siv los hloov lub amplitude ntawm crane, uas yog, hloov cov kab rov tav nyob rau hauv nruab nrab ntawm tus nuv (los yog grab) mus rau lub axis ntawm crane rotation center, thiaj li mus hloov. mus rau kev thauj khoom thiab tshem tawm cov khoom los ntawm crane nyob rau hauv cov xwm txheej sib txawv.
