Set-up geometry should provide rapid rounding and avoid convenient waviness.
• Convenient waviness and marginal stability cannot be completely avoided. However, convenient waviness is unlikely to be a problem unless waviness is forced by vibration at the same frequency.
• Static compliance in the system softens the imposition of errors into the workpiece and, hence, makes it easier to achieve low roundness errors.
• Resonant frequencies should be avoided since these amplify vibrations and cause large roundness errors. Resonant vibrations are minimized by well-designed structures and high damping.
• Forced vibrations at a resonant frequency should be avoided. This can be achieved by checking that excitation due to motors, drives, and wheel unbalance are not at a frequency coincident with a dominant machine resonant frequency.
• Sources of forced vibration such as wheel unbalance should not be allowed to excite a frequency of marginal geometric stability.
• Many problems can be overcome by adjusting workspeed. Ideally, a machine should provide a continuously variable range of workspeeds.