The linkages are 3D printed and were initially constrained using #8-32 1/4" standoffs with washers. The standoffs were too long resulting in unwanted translation of the mechanism.

Early Version of Prototype. Motor is constrained with zip-ties and linkages are constrained by #8-32 bolts.

To improve the mechanism, I used M3 bolts with locknuts to eliminate any translation within the linkage system. In addition, I used a 3D printed part with T-nuts to slide the aluminum extrusion along. This piece is shown below

Stationary portion of slider joint.

Rev2 of the Assembly with Slider constrained by T-Nut

This assembly did not have smooth frictionless motion as the 3D printed part kept binding against the aluminum extrusion. I added bearing wheels to the assembly to fix this issue. The final assembly is shown below.

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