Our playground set is super old and there's no parts being sold.
So, I measured the original old one and modified a bit to fit to the pole.
I also put the original design as well.
I used Overture ASA and it took 10 hours to print.
Stool is fixed with ¼"-20 1" machine screw to the pole with ¼" hold flat washer.
There's ¼" hole with 0.28" long steel barrel at the axis to make it rotate while note scraping off the contact point in the original product.
I resued that part to assemble.