3D model of byu_cmr
The models were repaired and checked for printability.
A CORE, or compliant rolling-contact element, is composed of two cams joined together
...Plus with multiple complaint flexures. Tension develops in these flexures as the cams roll in contact with another; this holds the cams together. This motion allows the CORE to mimic the rotation of a pin joint. The developable CORE, or D-CORE, allows this CORE joint to be manufactured from a single sheet and stored in a compact position. Some advantages a D-CORE might have over the traditional pin joint include decrease in friction and wear, the mitigation of backlash, decreased cost of manufacturing, and decreased weight and possibly size. The most sizable difference between the motion of a D-CORE versus a pin joint is the axis of rotation. When a D-CORE rolls, its axis of rotation is moving. The movement of this axis of rotation is calculable but not dismissible; therefore, if an application requires a fixed axis of rotation, the use of a CORE mechanism will likely be impractical.
Printer brand:
Prusa
Printer:
i3 MK3
Rafts:
No
Supports:
No
Resolution:
0.2
Infill:
20
Filament brand:
Prusa
Filament material:
PLA
Notes:
To assemble this mechanism print 2 D-COREBases and 1 D-CORE.
Note: If needed, add a small amount of super glue onto each tab before inserting them into their proper places as shown. This will help secure each flexure while the D-CORE is in use.
The CORE joint has shown promise in multiple biomedical engineering applications including orthopedic joint replacements and brace designs.
The figure below shows a modified CORE design presented as an option for spinal disc replacements. This design achieves a healthy quality of motion for lumbar replacement as well as decreased wear compared to other replacement options.
Alexander Henry Slocum, a previous student at Massachusetts Institute of Technology, also used the principles of this CORE mechanism to develop knee and hip replacements, as well as a more advanced joint for a knee brace.
The D-CORE’s ability to store compactly also could have many advantages when it comes to space-constrained applications. These applications include minimally invasive surgeries, medical implants, aerospace technology, and even household furniture.
Halverson, P. A., Bowden, A. E., & Howell, L. L. (2012). A compliant-mechanism approach to achieving specific quality of motion in a lumbar total disc replacement. International Journal of Spine Surgery, 6(1), 78-86.
Nelson, T. G., & Herder, J. L. (2018). Developable compliant-aided rolling-contact mechanisms. Mechanism and Machine Theory, 126, 225-242.
“Deployable Joint,” Howell, L.L., and Nelson, T.G., U.S. Patent 10,227,804, issued March 12, 2019.
“Spinal Implant,” Halverson, P.A., Howell, L.L., Magleby, S.P., and Bowden, A.E., U.S. Patent 8,308,801, November 13, 2012.
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