I noticed that whenever I would backup my droid quickly that my center foot would rear back causing it to dig in and actually stop my droid or cause him to drag his foot. I also would notice the side feet arc forward a little if I would accelerate quickly. That cant be very good for traction so I thought to correct that action by placing wedges in between the ankle and the foot housing to lock the feet in place. This also brought up a concern I had. I wanted to make sure my droid was at the proper angle before I locked the ankles into position. Once I had determined the ankle was correct and not conducive to a ill timed face plant (i.e. the droid is standing to tall or forward), I installed the locks. This had a nice side effect for the outside leg motors of improved traction and response. For the center foot it cured the moon walk problem on backing up. However, it cause another problem. It started hitting the front of the center foot whenever he would go up surfaces with a sharp incline. The ankle lock wasn’t allowing the foot shell enough movement to clear some obstacles so I had to relax or open up the arc of the ankle lock to allow a little movement. Once that was done it seemed to work just fine. The ILM droid appears to have had ankle locks built in to the ankle design. This is something I didnt noticed until after I had installed mine……Interesting……….One thing I will do when I make them again is make them wider for the side motors to distribute the load better . This set was only 1/4″ thick. The next version will be 1/2″ thick for the side motors and 3/8″ for the front.