Variable span multistep straightening process for long/extra-long linear guideways

This paper presents a variable span multistep straightening process (VSMSP) to improve straightening accuracy and reduce the number of straightening steps for the multistep straightening of long linear guideways. It can also efficiently deal with the ineffectiveness caused by the single-step straightening process. The VSMSP adopts a sequence of three-point straightening processes with variable spans at different straightening positions. The paper presents the modeling of the behaviors of linear guideways in a straightening step and explains the use of the model to calculate the variables of the VSMSP. Key variables including span size, straightening position and straightening moment and stoke are optimized. The VSMSP and the model are validated experimentally on a straightening machine.