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The claw link (Link 3) and one of the spacers are laser cut out of Baltic birch plywood since their geometries are completely 2D. All other parts of the linkage assembly are 3D printed with holes oversized by 0.1-0.4 mm to make up for the additional wall thickness added by 3D printers. Parts of the linkage assembly are bolted together using M3 socket screws and nuts. Bearings are press fit into the joints and shafts are kept in place using friction from the shaft collars. We used 8 in diameter shafts and linear bearings for the sliders and 6 in diameter shafts and bearings for the pin joints. The added rubber on the end of the claw and the stationary grip are super glued to the linkage assembly parts.
Figure 4.3: Complete set of construction images in order regarding the linkage assembly
We initially had problems with machining the shafts and ultimately used a Dremel to cut them. Additionally, to reduce undesired movement which we observed upon initial testing, we added shaft end caps that are friction fit to the ends of the shafts.
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