Design of a prototyping press for 3-d monolithic compliant mechanisms

Abstract

The Precision Systems Design and Manufacturing Lab at the Massachusetts Institute of Technology has the need for a metal forming device capable of applying a plastic deformation to two-dimensional sheet metal templates of up to 1/8-inch thickness and 8-inch diameter in order to transform them into prototype three-dimensional monolithic compliant mechanisms. These mechanisms have applications in industrial positioning as they are highly accurate and free from normal performance reducers such as friction, wear, and backlash. This thesis presents the design of a prototyping press capable of achieving the deformation required to produce the 3DMCMs from their 2D templates. The prototyping press that is developed herein utilizes a multiple-piston, hydropneumatic cylinder to deliver up to 5,000 lbf over a 4-inch stroke. The press offers force sensing to within 10%, displacement sensing to within 0.005 inches, and rate control centered around a 6-inch per minute average rate. It is powered by a compressed air supply at up to 100 psi and motion is controlled by a single electrical solenoid shut-off valve.