bˌʌt ɪnstˈɛd ðə dˈɪsk ɪz mˈaʊntᵻd æɾ ɐn oʊblˈiːk ˈæŋɡəl, wˌɪtʃ kˈɔːzᵻz ɪts ˈɛdʒ tʊ ɐpˈɪɹ tə dᵻskɹˈaɪb ɐ pˈæθ ðæt ˈɑːsɪlˌeɪts ɐlˈɔŋ ðə ʃˈæfts lˈɛŋθ æz əbzˈɜːvd fɹʌm ɐ nˈɑːnɹoʊtˈeɪɾɪŋ pˈɔɪnt ʌv vjˈuː ɐwˈeɪ fɹʌmðə ʃˈæft.
But instead the disk is mounted at an oblique angle, which causes its edge to appear to describe a path that oscillates along the shaft's length as observed from a non-rotating point of view away from the shaft.