D.i.y sulky

I was thinking about making a homemade sulky for my walk behind and mounting a 2" towball to the rear of the mower to act as the swivel point. This should give me all the movement I need? Also going to make it a wheel-less skid plate, I saw one online somewhere, probably YouTube. Any thoughts or comments welcome.

It will work with just a ball on flat lands I imagine but a manufactured unit has more swivel points to avoid binding. Hill crowns, dips and uneven grounds will put some stress on the ball and hitch.