Answer
Ana amfani da madaidaicin madauri don faɗaɗa zobe na karkace na waje don a iya zame shi a kan sandar kuma zuwa cikin tsagi. Babban diamita na mandrel yakamata ya zama kusan $1%$ zuwa $2%$ ya fi girma fiye da diamita, kuma 'taper' ko kusurwa yakamata ya zama marar zurfi (yawanci $10^\circ$ zuwa $15^\circ$) don hana yawan damuwa da zoben. Ana tura zoben zuwa ƙasa ta hanyar amfani da plunger ko hannun riga. Matsakaicin ƙira mai mahimmanci shine 'Mafi girman Iyakar Faɗawa.' Kada a taɓa faɗaɗa zobe kamar yadda ID ɗin ya wuce $D_{free} + (\sigma_y D_f^2 / E b)$, inda $\sigma_y$ shine ƙarfin amfanin gona. Wucewa wannan iyaka zai sa zoben ya ɗauki saiti na dindindin, yana haifar da rashin daidaituwa a cikin tsagi. Don haɗuwa ta atomatik, saman mandrel dole ne a taurare kuma a goge shi don rage juzu'i da hana ɓarna saman zoben.
