Linkage Prototype

MATLAB:

We decided to develop a Watt's sixbar isomer because it could combine two motions into one degree of freedom. The two motions that we desired were a 'reach down' motion and a 'flip around' motion. Using vector position analysis, we developed MATLAB code to calculate and solve for linkage lengths that met our requirements. We needed the claw to face away when fully extended, and flip back towards the user when retracted. 

SolidWorks:

With the previously found link lengths, a basic model was created in SolidWorks in order to visualize the range of motion. This model can be seen here. After confirming that this is the desired motion, we refined the model for manufacturing. This included making all pinholes either 5mm or 11mm to fit with the provided shafts and bearings. The updated model would be used to create g-code required for manufacturing. 

Manufacturing:

For manufacturing our initial prototype, we decided to make it out of CNC'd mahogany plywood. The sheets provided were 3/8 inch thick, and we used the X-Carve 3D wood carving machine in the wood shop to cut out our links. Once the links were cut, we sanded down all of the edges and press fit our shafts and bearings to create our assembly. The prototype result can be seen here. 

Motion of the linkage

Initial linkage prototype out of wood