The mobile base that I showed up above, if built with enough accuracy, forces the legs to settle into the corner pockets. I built the one for my bandsaw and the enclosed base of my saw sits inside of the four corners very tightly. In fact, if I recall, I had a heck of a time got get the base of the saw inside of the base. It sits very firmly. The only problem that I have is when they built the storage room on the side of our mobile home, they put it on 4 x 4's but not enough of them. Then they put down plywood for the floor and it is a bit springy. I was always going to add another layer over it but never got around to it and now it would be a major undertaking to do it. Oh well.............