The plan was to repaint and fix a drab old rental skee-ball machine.
First, I disassembled the machine a bit to assess things. The heart of the machine were plastic targets with integrated ramps and optical sensors. Unfortunately, these were blow-molded and had become brittle and were damaged beyond repair.
The broken targets rendered the game’s electronics completely nonfunctional. 
I talked with the client and we decided to fabricate durable new targets and ramps and simplify the planned paint job to keep the overall project within budget.
I made the new targets from hardboard paneling and rigid foam. 
Transplanted ball sensors and wiring harness.
Making new targets and ramps changed the project from one of refurbishment to one of game engineering and design. It took a couple tries to find the ratio of hole size to ball size to get the balls to “circle the drain” in a satisfying way, and I spent a while experimenting to learn the right shape for the ramp to lob the ball at the target without skittering across it.
Ball return mechanism. 
Reassembled for playtesing before refinishing.
The finished machine looked snappy, if a little plain for a carnival machine. But it’s durable enough to last years and it played, counted, and sounded great.
