  Parallel kinematic mechanisms are interesting alternative designs for
machining applications. Three 2-DOF parallel mechanism architectures dedicated
to machining applications are studied in this paper. The three mechanisms have
two constant length struts gliding along fixed linear actuated joints with
different relative orientation. The comparative study is conducted on the basis
of a same prescribed Cartesian workspace for the three mechanisms. The common
desired workspace properties are a rectangular shape and given kinetostatic
performances. The machine size of each resulting design is used as a
comparative criterion. The 2-DOF machine mechanisms analyzed in this paper can
be extended to 3-axis machines by adding a third joint.
