I backed a indiegogo project that was supposed to deliver a ping pong robot but they did not deliver.
Here's a post I wrote about it https://medium.com/@mkirank/trainerbot-table-tennis-robot-re...
I started playing around trying to see how this works and built one. The robot is built using laser cut and 3d printed parts.
I've used johnny-five, express, sequelize and some python.