Works fine. I had to add some angle iron down two sides in order for it to hold a plywood base. Nothing for the plywood to lie on.
Seems like a waste of space if you don't have a shelf there. Anything you store under it would have to be moved before you could roll it around.

It comes with one long and one short extender for each side. If you use one long and one short on each side, then it will be about 36x36. The only way you can get the 52" length they talk about is to move one of the extenders to each of the long sides, but then the short sides are even shorter.
That's why they say it can be up to 36x36 OR up 20x52.

I used this for a 400-plus pound Grizzly shaper (the base was rated at 600lbs). Other reviewers have commented on the lack of clear assembly directions, but I usually ignore the instructions anyway. I assembled the casters and lever assemblies first, simply because I wanted to see how they worked, and then added the rails, not tightening any bolts until I was ready to install. It took about an hour, but my time would have been cut almost in half if I'd had another person to help pick up and set the shaper on the dolly. Instead, I tipped it side to side and back and front, wedging a 6" length of 2x4 under each side, then slid the base in mounted the front rail. No complaints, it now rolls effortlessly when needed and stays put when not. Highly recommended

Wow, easy to setup, Price is ok for this heavy duty frame and huge easy rolling wheels and brake. I bought 3 units and they handle the joiner, 14" band saw and a huge Incra router table and stand with ease. Also, they roll easily, you just need to gently steer them. Buy them you will like them.

The saw is a dream to move around the shop now. I have a 2 car garage workshop and need as much space a possible. These wheels make it very easy to get the saw out and put it away. My saw with the fence is 8 ft long and over 350 lbs and I swear my 7 year old could move it around easily.

I wish I would have bought this sooner.

I purchased two of these initially - one for my bandsaw and one for my mortiser. I ended up getting a third for my jointer. Very satisfied with all three.

The corners are very solid and assembly is simple. The assembly instructions are minimal at best. An expanded diagram would be of great assistance. The one in the instructions is only about 2.5" square.

The only downside that I see is that the one I have under my jointer will move a bit with the wheels locked. That is mainly because it is much lighter than the other two tools that I have mounted on these. It is not enough movement to be concerned about, but the jointer feels less solid than the other two tools.