I know this is years old, but I wanted to answer this question.
No, you typically want to use (3) skates and not (4). It is called a triangle of stability and machinery movers rely on (3) skates to make sure weight is always on the skates. It you use (4), you need to tie/attached all skates to the machine so when a corner get light, the skate stays under the machine. No floor/surface is perfectly flat. With (4) skates the machine will literally leave a skate behind at some point during the move then regain weight on that corner and drop to the ground. This is much less likely to happen with (3) skates, but you still need to watch. (2) skate wide, typically on the heavy side & (1) skate centered on the lighter side
Cut pieces of plywood narrow enough to fit into the “tray” the plywood needs to be a little bit thicker than the height of the sides on these skates.






