Most of my woodworking machines are on mobile bases. Some work better than others but the best is one that was made by the previous owner of my cabinet saw. It's a simple design made out of 2" square tube with hard rubber wheels, 1 swivel on one end and 2 fixed on the other. It's my largest base that spans the cabinet saw and extension table but is the easiest to move around. The design works so well that I'm planning to make and replace all of my other bases with the same design. What is your preferred mobile base?