What fun! One of our engineering customers has taken time off from business to print a marvellous fun object.
It is the “The Cyclone: triple lift, triple track marble machine” , by mroek, published
It can be found at: https://www.thingiverse.com/thing:1340784
This one was printed in PETG and took about 23 hours to print and stands a fraction short of 160mm high.