This is the first prop of any kind I've tried to make, so I'm learning as I go. A friend challenged me to make some BTTF shoes that actually autolaced. So this is what I came up with: It all hides behind the strap on the back of the ankle and uses fishing line to reel in the top strap. It's not as fast as the movie, but it's quite strong. I had to cut my way out a couple of times while testing. I also put a pressure sensor in the sole of the shoe so as you put your foot in, it automatically tightens. I have all the parts I used and an obnoxious, over-produced video on my website: http://www.hscott.net/shoes/ The other day I made version two, which is much simpler: This version runs on a single cell lithium ion battery, which allowed me to remove some of the circuitry from the first version. This means that the motor turns slightly slower, but I figured the simplicity I gained was worth it. To precisely control how tight the straps get each time, I put an encoder on the end of the motor so count rotations. Just using timing didn't end up working very well. I'm curious about what other mechanisms people have used to accomplish autolacing?