Faculty Advisor

Norton, Robert L.


Gillette Boston (old MQP)


This project redesigned components that were causing occasional binding of a cam-driven product inserter station on an assembly machine at the sponsoring company. The device consisted of a vacuum gripper and set of mechanical strippers guided by telescoping slides whose strokes were limited by a series of hard stops. We created parametric and dynamic models of the mechanism using CAD and FEA software, gathered experimental data using accelerometers, and examined the assembly through high-speed video and physical inspection. We discovered that the binding occurred within the inner slider assembly, where one of the hard stops applied large forces and moments and caused excessive wear to the sliding surfaces. We redesigned the assembly to increase the slide's bearing ratio and decrease the effect of the applied moment. Also, we implemented a new cam and observed a 17% decrease in acceleration during the hard stop and a 4.6% decrease in RMS acceleration over one cycle. We are confident that our redesign, if fully applied, would effectively eliminate the binding.


Worcester Polytechnic Institute

Date Accepted

January 2008


Mechanical Engineering

Project Type

Major Qualifying Project