Hi. With great advice, I'm making a gizmo to turn a tombstone into a Christmas package using a pneumatic cylinder and an up-and-down motion. https://www.halloweenforum.com/tutorials-and-step-by-step/197801-early-work-tombstone-flipper.html I'd like to have another prop--also changing from a tombstone to a Christmas present--using a spinning motion...like a turnable, with a tombstone on one side, then it spins 180 degrees, revealing the package on the other side. I thought it would be cool having different types of transitions as my house alternates between Christmas and Halloween decorations. Because I use Light-o-Rama controllers to synchronize to music, I'm limited to a design that has the prop in one position when power is applied and in the second position when the power is turned off. Suggestions for a 180 degree spin?