A microprocessor controlled cap gun. On each button-press two timed pulses of electricity are sent to a motor assembly, turning it forward for a fraction of a second then reversing it. The motor assembly tightens a modified bike brake cable that feeds into the grip of a toy cap gun. The cable pulls and releases gun's trigger, which then fires off a cap.
Despite my best efforts and several modifications to the motor assembly to reduce wear on the cable, it snapped a few hours after being installed in the gallery.
First version of the cap gun.
Second gun with improved trigger assembly.
First gun installed.
Second gun installed.
Circuit controlling the motor assembly. An Arduino waiting for a button press to switch three relays via mosfet transistors.
Early crude trigger assembly.
Installing the relays.
Close-up of the motor assembly.