My table saw needs to be mobile so I can put it away against the wall when I’m not using it. The existing products are expensive or don’t fully swivel. I came up with a cheap and convenient solution using flip-down casters.
Pretty happy with how this turned out, even months later
You mentioned it was hard to get the wheels down because the crossbars match (saw + wheels). Instead of using spacers, you might also consider putting a small tab of wood in the middle on top of each wood crossbar so it sits above the saw crossbar, but not big enough to touch the floor when down.
I have what look to be almost those exact wheels on my table saw platform. I have a jobsite saw for which I built a cabinet, and I also put flip casters on it. I love them! They're miles better than the "locking" ones that just roll while you're trying to cut things.