Started out as Wicked Monkey in an Oz LARP. First set of wings I gave myself the following parameters. The wings had to extend out, instead of up as most Cosplay wings do. I could sit with them on, and not walk sideways through doors. First generation used pulleys and springs. Second generation I cannibalized a Harbour Feight 18 VDC cordless drill and 5/8 all thread for a homemade actuator. While this worked for the LARP it took a full minute for the wings to extend and contract. An 18 VDC battery pack gets heavy after a while.
Third generation used I use two cordless screwdrivers. Combined they weighed less than the 18 VDC drill and opened the possibility of getting the wings to flap. Tweeting the wings I shaved 5” in height and cut the open/closed time in half.
Fourth generation, inverting the motor allowed me to decrease the mounting size of the wings. And play around with differnent gearing. Using the motor housing as a guide did increase the width.