A few years ago, I worked on a show that had three Kabuki drops. One was
china silk and the other two were 22 ounce
velour. They were all 24' x 54'. The mechanisms were long pieces of 1by. One piece was fastened to the bottom of the pipe
batten, and the other piece was attached to the first piece with hinges on the bottom. There were steele pegs running out at a slight angle up from the front board. The Kabuki had grommets in the top, that were placed over the pegs. There was a 120vac
solenoid mounted in such a way that it released the front board allowing it to fall forward and the kabuki would then slide off the pegs and fall to the floor. Because the
curtains were quite heavy, the front board was divided into 3 sections with each having a
release mechanism. The solenoids were powered by a
dimmer circuit and the board was activated by SEMPTE from the audio
track. It was pretty cool, and did 4 to 5 shows a day for a year, that I was there.
It wouldn't be difficult to make a much smaller version using a 12 or 24 dc
solenoid to
release it. I just recently purchased that type of
solenoid from either mpja.com or electronic gold mine. I don't remember which one at the moment.