A homemade CNC machine for cutting PCBs.

Boston Dynamics' robot dog, Spot Mini is unavailable at any price. A Chinese copy is $30,000. Cut 99% of the cost and build one at home.

Say Alexa the move, it is automated using the xy plotter that we have made especially for Chess.

A4 size CNC 2D Plotter using Processing, Arduino, L298 and Stepper Motor | A4 CNC Plotter

Make this robot moves by just moving your hand!

Make an R2-D2 replica and control it by an app you programmed. Add a Nokia interface which gives you the Star Wars characters info.