Manufacturing
The final design for my mechanism did not have any parts that had significant depth, so I decided on using the laser cutter to create all of my parts. I created all my parts using Retina Engrave and cut out the parts from ⅛” wood. Figure 5 below displays the cut outs of my parts within Retina Engrave 3 and Figure 6 displays the majority of my parts after manufacturing.
Figure 5. The designs I made within Retina Engrave 3 to be cut by the laser cutter.
Figure 6. The laser cut parts made from 1/8" wood.
Assembly
Using these parts, I constructed the claw mechanism. I used the hole in the plate to connect the micro-servo motor to the small gear using a servo horn. While doing this, I noticed that the gear had a significant amount of play when the gear was attached to the servo horn at only the center. I made a note to add parallel holes to the center of the gear to attach the gear to the servo horn in more than one point. After doing this, I attached the claw parts to the plate and aligned one of the claw gears to mesh with the small gear. The joints in this mechanism were made of M3 screws, nuts and 7mm ball bearings. The first prototype of the claw is shown in Figure 7.
Figure 7. The first claw prototype.
After testing out the initial claw prototype, I noticed that the claw felt loose after closing and opening multiple times. I concluded that parallel four bars linkages were needed in both the top claw and the bottom for the claw to be stable. This would mean that the final prototype of the claw would consist of 4 four bar linkages.