Early Concepts

Copper block concept to increase overall heat transfer to plate. The copper would be expensive, and expansion coefficients of copper and steel are similar which would make a copper puck/steel pin press fit more secure.

Early compliance idea: spring steel flexure embedded inside bottom of puck. There would be a 90 degree section of aluminum material and a 90 section of void that the flexure would be rotated through.

Copper ribbon concept to increase heat transfer near pucks. The small section of ribbon would take heat from below and provide a more direct path near where the pucks sit. Both ideas don't address the poor heat path directly.

Flexure would allow two section of the pucks to rotate independently to a degree and would also stop pucks after 90 degrees of travel. Having two surfaces rotating independently would lead to having two sliding faces, however.

Early hard stop flange attached to the bottom of pucks with a tab that would collide with a fixed block to stop it and the puck's rotation. 

Early hard stop block which restricts path of hard stop flange above. Flange could travel through void sections, but would collide with diamond-shaped protrusions. Both the hard stop flange and block would be made of steel.

Initial idea would used linear motion of actuators to bend spring steel flexures to approximation linear motion for connecting bar. Bar would attach to spring steel ribbons wrapped around each puck in order to rotate the array of pucks. 

These two parts were modified and included in the final design. Early versions of the hard stop flanges modified to better the heat path to the puck body and to simplify the design. Early versions of the hard stop block was replaced to simplify the machining and assembly process by smaller individual blocks.

Initial idea using timing belt to rotate all pucks together. Timing belt idea used in final design, but permanent roller locations and connection to cam puck modified.