Linear-Motion Compliant Mechanism

Summary

This design was developed for a safing and arming mechanism for nuclear weapons. The use of compliant mechanisms allowed the design to be scaled down with some components the size of a human hair, yet still being reliable.

The design is a linear-motion large-displacement compliant mechanism. Other examples of these types of mechanisms can be found on Thingiverse here.

X-Bob

The X-Bob, as illustrated below, is an example of a planar, large-displacement device consisting of a center shuttle on a compliant suspension. An X-Bob is created by combining four Robert’s mechanisms in a reflective way so as to restrain the shuttle’s movement to one-degree-of-freedom. The X-Bob configuration has proven to be effective for micro-systems; a micro machined version is also shown below. The X-Bob shows low torsional off-axis stiffness but high transverse stiffness. 

Learn More

This design was developed by the Compliant Mechanisms Research Group (CMR) from Brigham Young University (BYU). Follow us at @byucmr on Instagram or visit the BYU Compliant Mechanisms Research (CMR) website to learn more about compliant mechanisms.

See https://rdcu.be/dnHx0 for an article in Nature Communications about how and why we share these maker resources.

Check out a similar build here: https://www.printables.com/model/583713-large-displacement-linear-motion-mechanisms. 

Technical Information

For in-depth technical information, see the following publications: 

Hubbard, N.B., Wittwer, J.W., Kennedy, J.A., Wilcox, D.L., and Howell, L.L., “A Novel Fully Compliant Planar Linear-motion Mechanism,” DOI:10.1115/DETC2004-57008, Proceedings of the 2004 ASME Mechanisms and Robotics Conference, DETC2004-57008. 

Kennedy, J.A., Howell, L.L., and Greenwood, W., “Compliant High-precision E-Quintet Ratcheting (CHEQR) Mechanism for Safety and Arming Devices,” Precision Engineering, Vol. 31, No. 1, pp. 13-21, 2007 

To learn more about compliant mechanisms in general, see the BYU Compliant Mechanisms Research (CMR) website or these books: Compliant Mechanisms, Handbook of Compliant Mechanisms 

Intellectual Property

The downloadable 3D print files provided here may be used, modified, and enjoyed for noncommercial use. To license this technology for commercial applications, contact:

BYU Technology Transfer Office

3760 Harold B. Lee Library

Brigham Young University

Provo, UT 84602

Phone: (801) 422-6266 

https://techtransfer.byu.edu/contact