This custom R2-D2 LEGO minifig started at as a regular Hasbro toy. First, the figure had its sound board removed. Next, brickmodder “did some extensive testing and rerouting of the traces and components” so everything would fit inside the minifig. Continue reading to see the final result.
I used a 6mm x 6mm tactile switch in the dome and everything is running from a CR1225 battery inside the “body”.