Answer
Karkatattun zoben riƙewa yawanci juyi 2 ne ko 3-juyawa. An haifar da damuwa na radial a lokacin shigarwa ta hanyar haɓakawa (don zobba na waje) ko ƙaddamarwa (don zoben ciki) da ake buƙatar wucewa a kan shinge ko cikin rami. Matsakaicin damuwa $\sigma_{inst}$ ana bayarwa ta $\sigma_{inst} = \frac{E t (D_f - D_i)}{D_m^2}$, inda $D_f$ shine diamita kyauta kuma $D_i$ shine diamita na shigarwa. Saboda zoben juyi 2 ya fi sirara fiye da zoben hatimi guda ɗaya na ƙarfi ɗaya, yana iya fuskantar nakasu mai ƙarfi ba tare da samun nasara ba. Koyaya, idan zoben ya 'fi girma' yayin shigarwa, zai ɗauki saiti na dindindin kuma ba zai zauna sosai a cikin tsagi ba, yana haifar da rashin ƙarfi da rage ƙarfin turawa. Zobba masu juyawa da yawa suna rarraba damuwa na shigarwa cikin daidaituwa a cikin coils idan aka kwatanta da zoben sashe akai-akai.
