extramobile, intramobile, mechanical engineering, developable, mechanisms


Mechanisms that can both deploy and provide motions to perform desired tasks offer a multifunctional advantage over traditional mechanisms. Developable mechanisms (DMs) are devices capable of conforming to a predetermined developable surface and deploying from that surface to achieve specific motions. This paper builds on the previously identified behaviors of extramobility and intramobility by introducing the terminology of extramobile and intramobile motion, which define the motion of developable mechanisms while interior and exterior to a developable surface. The limits of motion are identified using defined conditions. It is shown that the more difficult of these conditions to kinematically predict may be treated as a non-factor during the design of cylindrical developable mechanisms given certain assumptions. The impact of toggle positions for each case is discussed. Physical prototypes demonstrate the results

Original Publication Citation

Butler, J., Greenwood, J., Howell, L.L., Magleby, S.P., “Limits of Extramobile and Intramobile Motion of Cylindrical Developable Mechanisms,” Journal of Mechanisms and Robotics,, Vol 13, 011024-1 to 011024-8, 2021 6

Document Type

Peer-Reviewed Article

Publication Date



Journal of Mechanisms and Robotics




Ira A. Fulton College of Engineering


Mechanical Engineering

University Standing at Time of Publication

Full Professor