Hubelino / Duplo compatible marble run items by advancedvb on Thingiverse.

Prusa Mk3S: 0.2mm resolution, 0.4mm nozzle, Devil Design Blue / Yellow PLA, 3DE Basic Silver PLA. Print time 4¾ + 3½ + 1 hours.

24.35mm sphere.

Prusa Mk3S: 0.2mm resolution, 0.4mm nozzle, 3DE Premium Shimmer Dark Green / Silky Candy Pink PLA, Rosa Starter Apple Green PLA. Print time 1¼ hours.