I would use a wheel hub. they can take hundreds of kilos of lateral load, and when based vertically Instead of horizontally run very true and smooth. They often have wheel studs already mounted, and the other end has theaded holes. Super simple to mount to.

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSulUfl_XXS0sirzl57Cib7F0RvtX7tJSYV5g&usqp=CAU