CurvedLinks: Medium Size Circular Links

CurvedLinks were developed for quick turn-around proof-of-concept prototyping of developable mechanisms by the BYU Compliant Mechanism Research Group. Combined with commercial components from the LEGO Group, a wide range of developable mechanisms can be created.

What is a Developable Mechanism?

A developable mechanism is a mechanism that, at some point in its motion, conforms to a developable surface. In other words, it is a device that can move and that is shaped to match a curved surface in a certain position.

If the the CurvedLinks are connected so that in one position they match the base circle, you've created a developable mechanism.

Visit the BYU Compliant Mechanisms Research (CMR) website or see this video on how New devices morph and transform - like Iron Man's suit to learn more about developable mechanisms.

How to Make it

We recommend that you print at least one circular piece, as well as several other of the curved beams and some connector pieces for this Thing. That way you'll have enough pieces to experiment building with.

3D Printing

The CurvedLinks can be 3D printed using any rigid filament. We print with PLA and find that works well. Support material is not necessary, but may help ensure the countersink holes come out the right depth.

Assembly

Use CurvedLinks just as you would any other LEGO-compatible part. Connect them together using LEGO joint connector pieces.

Using With Other CurvedLinks

There are several other types of CurvedLinks that we've designed. There are different sizes and lengths that you can experiment with.

We've also designed each set of CurvedLinks to work with each other. The small set fits inside the medium set, which fits inside the large set, and adapter pieces link the sets together as part of the same mechanism. Nestling the circles inside one another can give motions that you otherwise would not have achieved.

Find our other CurvedLink files here:

CurvedLinks: Adapter Pieces

CurvedLinks: Large Size Circular Links

CurvedLinks: Medium Size Circular Links

CurvedLinks: Small Size Circular Links

Learn More

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

Technical Information

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

Nelson, T., Zimmerman, T., Magleby, S., Lang, R., and Howell, L., “Developable Mechanisms on Developable Surfaces,” Science Robotics, Vol. 4, Issue 2, DOI: 10.1126/scirobotics.aau5171, 2019.

Greenwood, J.R., Magleby, S.P., and Howell, L.L., “Developable Mechanisms on Regular Cylindrical Surfaces,” Mechanism and Machine Theory, Vol. 142,
https://doi.org/10.1016/j.mechmachtheory.2019.103584, 2019.

Hyatt, L.P., Magleby, S.P., Howell, L.L., “Developable Mechanisms on Right Conical Surfaces,” Mechanism and Machine Theory, Vol. 149, paper no. 103813,
https://doi.org/10.1016/j.mechmachtheory.2020.103813, 2020.

Sheffield, J.L., Sargent, B., and Howell, L.L., “Embedded Linear-Motion Developable Mechanisms on Cylindrical Developable Surfaces,” Journal of Mechanisms & Robotics, Vol. 16, 015001-1 to 015001-11, https://doi.org/10.1115/1.4062133, 2024.

Hyatt, L, Greenwood, J., Butler, J., Magleby, S.P., Howell, L.L., “Methods for Mapping Mechanisms to Developable Surfaces,” International Journal of Mechanisms and Robotic Systems, special issue associated with the 2020 USCToMM Symposium on Mechanical Systems and Robotic, https://doi.org/10.1504/IJMRS.2021.115154, Vol. 5, Nos. 1-2, pp. 39-60, 2021

Seymour, K., Bilancia, P., Magleby, S., Howell, L., “Hinges and Curved Lamina Emergent Torsional Joints in Cylindrical Developable Mechanisms,” Journal of Mechanisms and Robotics, https://doi.org/10.1115/1.4049439, Vol. 13, 031002-1 to 031002-8, 2021.

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, https://doi.org/10.1115/1.4048833, Vol 13, 011024-1 to 011024-8, 2021.

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 developable mechanism 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