Prototype Iterations (07)

Build Iteration 1: Pantograph-type Mechanism with Acrylic

Description: Parts cut from acrylic designed with CAD. M4 screws are used as joints. Motion is provided by moving gear manually.

Conclusion: The unhooking motion does not clear the bars. Need mechanism that can produce a more apparent unhooking motion profile.

Build Iteration 2: Klann Mechanism with Acrylic

Description: Parts curfrom acrylic. Locknuts used as joints to prevent unscrewing. Total of three layers to accomodate linkages without interference. Detachable grip arm to prototype grip.

Conclusion: The joints have considerable friction and move around even when crank is stationary. Need assembly that makes it move smoother and minimize play.

Build Iteration 3: Klann Mechanism with Bearing and double support joints

Description: Double supports for linkages to avoid movement of linkage out of plane. Crankshaft built with press fit to acrylic linkage. Bearing are used for rotational motion.

Conclusion: Press fit bearings come off the link while in motion. Small play with the bearing and shaft is enough to jam mechanism. Crank shaft slips when there is high force. Assembly was difficult. Motion profile was desirable.

Build Iteration 4: Compact Klann Mechanism with 3D printed parts

Description: 3D printed parts were used to decrease number of linkages and joints. Press fits are minized by adopting shaft collars in the print. The snap fit joints are used to make the design more compact.

Conclusion: Printing the parts tend to fail for thinner portions. Design looks more sophisticated especially for the grip and arm. Snap fit joints are prone to failure, so it is necessary to find a solution for compact joints.

Bill of Materials: